How do I add grunge & rusting texture to a pre-made material? [CYCLE] I am working on a nature scene where there is a car due to nature it gets rusted and rather by time it gets old. I want to add grunge and rust texture. I had bought materials plugin a while ago, so used the already made plugins from there. The problem is I have no clue where to apply the roughness texture since I am not that experienced.

Firstly, the grunge and rust textures are from megascan ( not sure if this helps).

First the glass material;

When you expand it this is what it looks like

Where do I apply the image texture of grunges which I got fro megascans to , where do I plug it to be exactly?

Second

I also have another metal material which has scratches over it, and it is premade, I would like to add some rust texture as well from megascans.

I can probably post the whole node, but I don't have 10 rep.

You mix nodes with Mix SHADERS use "fac" to blend between both influences. And then connect that last node to the Material output.

Here´s a 4 minute vid on how to make rust: https://youtu.be/hccqcCIGGUw
When you're done, connect it to the second plug on your mix node (the first one is your glass shader).


How is the vector transform node used? The Vector Transform node  has been a bit of a mystery to me. I would presume it would be useful more for procedural textures, but I have no idea how it should be used, or where it might be most useful.  Unfortunately, the manual does not have much to say on the node, and there is not much information, or any simple examples of usage anywhere that I have been able to find.

From the manual:

  The Vector Transform node allows converting a Vector, Point or Normal
  between World <=> Camera <=> Object coordinate space.

Knowing that we can convert from one coordinate space to another with this node, where might this be most useful?

To better phrase the question,  what is the correct way to use the vector transform node, and where is its application useful?

Overview

To effectively make use of the Vector Transform node, you first need to appreciate the differences between the various coordinate spaces - World Space, Object Space, and Camera Space.

You can get a feel for the different coordinate spaces by using the different modes of the Transform Orientation control in the 3D View.

Available 'modes' are Global, Local, Normal, Gimbal, and View.

Starting from the default scene, select the default Cube and press R, R and rotate it so it is no longer flat to the plane and click to accept the new orientation. With the Transform Orientation set to 'Global' you'll see that the control handles (the red, green, blue arrows) remain aligned with the world grid (the red and green lines on the grid)

This demonstrates World coordinates. If you use the Grab handles (the red, green, blue arrows) to manipulate the object it will move in World space - ie, the red arrow will move it in the X direction, green in the Y direction and blue in the Z direction.

Now change the Transform Orientation to 'Local'. The Grab handles (arrows) will swap to be aligned with the object's own orientation.

This demonstrates Object coordinates. If you now use the Grab handles to manipulate the object it will move in its own local (Object) space. ie, the Blue handle will move it 'up' in relation to its own axis rather than the world.

Now change the Transform Orientation to 'View'. The handles will swap to be aligned with the screen (you'll no longer see the blue one as it points directly away from the view - unless you move the objects away from the centre of the view - in which case it will point along the perspective line into the distance at the centre of the view).

This demonstrates Camera coordinates. Using the handles to move the Cube will move it parallel to the dimensions of the current view. Moving in the Z direction will move it closer and further from the view.

The above examples are useful to demonstrate the coordinate spaces for Location and Rotation. For World and Camera coordinates the scale is always the same - with 1 unit of World coordinate space equating 1 unit of Camera coordinate space. However, for Object coordinates, the object's Scale is also taken into account - if the object is scaled at a factor not equal to 1.0 then the Object coordinates will be similarly scaled - so for a scale of 2.0, one unit in Object space will be the equivalent of 2 units in World or Camera space.

The Vector Transform node is used to transform a Vector - whether it represents a Point, a Vector, or a Normal - from one space to another. The different 'modes' (Point, Vector, Normal) control which aspects of the space are used - useful when transforming to/from Object or Camera coordinates and the Location or Scale should be ignored - needs to be set appropriate for the type of vector being manipulated. Similarly, care must be taken to ensure the Convert From and Convert To options are set appropriately or the result will not be meaningful.

Here are some commonly available vectors :

Location - any object's Location is measured in World space, with (0,0,0) being the world origin. The Location is visible in the properties panel (N) and can be accessed via Drivers using the Transform Channel variable type or directly by using the material Object Info node.

Object Coordinates - the Object coordinates of the Texture Coordinates node returns the sample point on the surface (or in a volume) of the object in Object space. The origin of Object space is the origin of the object itself - so the vector describes the path from the object origin to the surface or volume point being considered in the shader.

The other nodes of the Texture Coordinates node aren't compatible with the Vector Transform node as they use subtly different coordinate spaces. In particular, the Camera socket should not be confused with Camera space coordinates used in the Vector Transform node as it is significantly different (the origin and scaling are different). Attempting to use those vectors with the Vector Transform will produce confusing results.

Normals are a bit tricky as their 'space' depends on which particular version of Normal you use - it's available on both the Texture Coordinate and Geometry nodes - with one being in Object coordinates (Texture Coordinate) and the other in World coordinates (Geometry). However, the Vector Transform can be used to translate these between the spaces (so you can use, say, the Texture Coordinate one where you'd normally use the Geometry one by passing it through a Vector Transform).

Two other interesting sockets of the Geometry node are the Position - which represents the point on the surface/volume - and Incoming, which represents the path of the incoming ray, both in World coordinates.

Vector Transform

To demonstrate the use of the Vector Transform, start with the default scene, rotate the cube some random amount and create the following material. The colours of the cube will effectively show the World Space coordinates - note that they aren't aligned with the cube and are, instead, aligned with the 'world'.

Now repeat the same but this time using Object coordinates from the Texture Coordinate node. You should be able to see the difference since the colours of the cube will remain aligned with the cube rather than the world.

To demonstrate the use of the Vector Transform node we can take the Object coordinates and transform them into World coordinates as shown (note the Vector Transform node settings Point, Object, World) :

The results should be identical to using the Position world coordinates directly. The Vector Transform has translated the Object coordinates into World coordinates.

One potential use of this is to shade an object based on the proximity of another object (or empty). By using Drivers we can get the World coordinates of an object into a material (using Transform Channel), then transform them into Object coordinates, then perform some calculation (such as calculate distance).

For example, the following material uses a driver to capture the Torus location and populate the input coordinates via the Combine XYZ node. This is converted from World coordinates into Object coordinates (which includes the translation for Location, Rotation and Scale of the object) and the Dot Product used to calculate the distance from the centre of the Torus (actually distance squared) and set the color accordingly.

As the Torus moves the surface of the cube changes color based on the proximity to the centre of the Torus.

Taking this a step further, we can affect the surface based on the proximity in Camera space - and can use that to affect a material based on how objects overlap in the camera view :

The material of the cube is such that when it's lined up with the magnifying glass (from the point of view of the camera) it becomes transparent. It works by converting the coordinates of the magnifying glass, and the point on the surface, into Camera coordinates. and calculates the distance between them. This allow it to determine whether the point lies within the diameter of the magn ifying glass lens and, if so, shade it as transparent. Note that the Z coordinate in Camera space indicates the distance from the camera. In this case the ratio of the distances is used to adjust the X/Y coordinates to scale based on distance. This makes the transparent region larger the closer the magnifying glass is to the camera.

So far the 'mode' has always been set to 'Point'. When used in this way the transform is assuming that the incoming Vector represents a point in space - in relation to the associated origin - and this means that the Object's location, rotation, and scale are all used in the calculation. If the Vector actually represents a vector that is independent of the location of the object (eg, a Normal) then you may need to ignore the object's location and/or scale. The 'Vector' mode ignores the object's location while the 'Normal' mode ignores both the object's location and the object's scale.

One example of how this can be used is to convert the Normal into Camera space and to use this to create a Toon-style shader based purely on the angle with the camera.

By passing a known fixed vector into the Vector Transform we effectively probe the properties of the object (eg, its orientation and/or scale) since the vector can be transformed into its Object space.

For example, this answer - https://blender.stackexchange.com/a/76237/29586 - uses the following material to determine how much an object is rotated away from a particular direction vector.

Using a similar technique we can extract the X, Y, Z scales from an object.

This material passes fixed unit-length vectors (one along each axis) into Vector Transform nodes set to Vector (so that the Location is ignored but Rotation and Scale are preserved) set to convert from Object space to World space and then measures the length of each resultant vector. The length of each vector will be a direct measure of how long that dimension is in the object once it is converted to World space coordinates - ie, it's scale in that direction.

EDIT : A further use is to determine the distance from the camera. For example, in this answer the vector transform is used to convert the distance into a color.


How to place images directly on object I'm currently learning Blender,exploring Skyrim 3D objects and wondering whether I can place my images directly on an object.

Or in other words, is it possible to add like a picture of a star, or coke bottle directly on an object (like a cube) and have it draw it's self on the object? ATM the only way i know how to edit the textures is directly with the draw tool.

I'm sorry if i'm not being clear enough, i'm still very new to blender.

The answer to your question asd71, is "sort of". You can place your 2D images directly on an object through the process of assigning image textures to materials, and assigning the materials to objects. And in one special case, one can assign an image to an object, specifically a plane object, and have the picture appear, something as a photograph of a painting.

However, it is not presently possible to assign an image like a star or a Coke® to a Blender object primitive and have the object be modified to the shape of the star or Coke® bottle. You must first create the mesh for the desired object, and then you can apply materials and textures to it.


How do I overlay Textures in Blender Cycles? I have an UV-mapped a mesh with a diffuse texture perfectly mapped, that appears in materials view.

Now, for ONLY specific parts of a texture, I want to overlay (as in screen, darken, multiply, soft light, overlay) another texture on top of a specific area of the diffuse texture. How is that typically done in blender? I don't want normal maps, I don't want specular, I just want diffuse and then alpha with overlay, likely using the mixRGB node.

Use the node tree you see here. The upper image node will point to that specific part of the image you want to overlay. You have to MASK those parts in the alpha channel  (I recommend you use .png with transparency) White=1 black=0 (non visible).

The second node it´s your regular image. The Texture coordinate nodes and mapping can share the plug for both images, but I´m doing it like this since I can sense in your post from what you write, this is what you want.

Thank you for your consideration to vote me as the answer by clicking to the left :the icon with a check mark and upvote this answer.

BFCT_Schiller


Will increasing samples reduce fireflies? Will increasing the samples eliminate fireflies? I know that the question of reducing fireflies has been already asked, but i want a straight answer on whether it will help or not.

Just posting for empirical data:

These renders are at 2000 samples with a Sun Lamp pointed at an Icosphere with 100% glossy shader... just to demonstrate differences between firefly reduction techniques:

For noise reduction, see this answer: https://blender.stackexchange.com/a/84326/38953


I am seeing both blender 2.8 and blender 2.81 in my program list. So can I uninstall blender 2.8? I have previously installed Blender 2.8 and today I have updated to Blender 2.81 by downloading and installing it from blender website. I see 2 blender programs in program list, one Blender 2.8 and Blender 2.81 which seems awkward. I thought it would rewrite the previous version which I already have but instead it creates a new blender program, although the desktop icon is still single and refers to Blender 2.81

So can I uninstall Blender 2.8 without uninstalling whole blender?
And is Blender 2.8 taking extra unwanted space in my hard drive?
and
How to update Blender the right way efficiently?
Can I update Blender without downloading the whole software again?

You can uninstall 2.8. Every version of Blender doesn't rely on other versions.

Updating Blender is usually done exactly how you're doing it. This is because Blender doesn't automatically update. Sometimes new versions break old files or addons, so it's up to the user to update the program by downloading it. It can be useful in certain cases to have multiple versions installed, although it's rare.

The only way to automatically update that I know of is if you install through Steam, although my understanding is that Steam basically does what you did just in the background.


How do I re-initialize a deleted image? My script creates an image, bakes to it and saves it. The first time, it works. However, if I try to re-bake to the same image, and in the mean time the user decides to delete the image from disk for whatever reason, bake throws an error:

RuntimeError: Error: Uninitialized image

How do I re-initialize an image to solve the user-deletion problem, or, say, to change its resolution?

I tried creating and deleting a new temporary image for each bake, and that sort of works, but if I do this at the end,

baketarget.user_clear()
bpy.data.images.remove(baketarget)

it leaves an unresolved reference in the uv/image editor, if that happens to be open at the time the bake is started. How do I unlink the image from the image editor?

I had the same problem, yet not with scripting, but with my blend file moving to another computer, and I didn't take saved images with me.

Go to UV/Image editor, press N to bring up the properties panel, and in image tab change source to "Generated". You can change the resolution there as well if you need to.

As for scripting, you probably need to do

bpy.data.images["your_bake_texture"].source = 'GENERATED'

I haven't tried it myself, but I suppose it is what you need, that's what the info panel shows when I change source. It works from console at least.

EDIT1: a quick script to reinitialize all images in all materials in the active object, provided you have selected the image texture nodes in all materials (you need to do this to bake your textures anyway):

import bpy

for slot in bpy.context.active_object.material_slots:

    mat = slot.material

    imag = mat.node_tree.nodes.active.image

    imag.source = 'GENERATED'


How can I loop two different animations with one playing right after the other? I am trying to loop two different animations in my game, one right after the other. In this case I am trying to have SlimeJump1 play, then SlimeJump2 play, then have them continuously play in this order. I have already tried delay sensors, and they won't work. How would I do this? The download link for the file is here. Thank you!!!

Ok, so to do this, you have to have two states. On the first one, you have an always sensor playing the first animation. Then you have a delay sensor that is set for 3 * length of animation - 50 hooked up to a state actuator that changes the state. The second state is the same, but you play the second animation.


How to see the python script used for an addon in a .blend file Some time ago, I wrote some scripts to rotate vectors in blender. I am not a blender expert. I have the files. I want to see the python script that I wrote.
The files work fine but although I can see the console and blender runs the code, I can't find out how to see the code.
For completeness I wrote the script inside the python editor built into blender. When I open the .blend file, the script runs automatically and generates the 3D image.
Can I do this?

split the screen and change the 3d viewport to text editor , click on the Open and select your python file , and you should get it , and i think you can also open them in notepad(not sure , try that for future)


How do I fix the "context invalid" issue when using python method weight_paint() I have the following test code that I am getting the infamous:

"RuntimeError: Operator bpy.ops.paint.weight_paint.poll() failed, context is incorrect".

I cannot figure out what the context issue is related to, is it the values for the stroke that I am trying to use, or selection, or something else.  Any help would be greatly appreciated!

Setup: a single plane that is subdivided multiple times it contains a single vertex group with all vertexes included called 'test'

Code:

strokes = []
brushOp = {
  "is_start":True,
  "location":(0.0, 0.0, 0.0),
  "size": 1.0,
  "time":0.0,
  "pressure": 0.0,
  "pen_flip":False,
  "mouse":(0.0, 0.0)
}
strokes.append(brushOp)
strokes.append({
   "is_start":False,
   "location":(1.0, 1.0, 0.0),
   "size": 1.0,
   "time":0.0,
   "pressure": 0.0,
   "pen_flip":False,
   "mouse":(0.0, 0.0)
})

bpy.ops.paint.weight_paint_toggle()
bpy.ops.object.vertex_group_set_active(group='test')
bpy.data.brushes['Draw'].stroke_method = 'LINE'
bpy.ops.paint.weight_paint(stroke=strokes, mode='NORMAL')

This most likely needs to be wrapped in an add-on that is in the 3d view (as in the button to call this is in the 3d view so that the last user input before this runs is in the 3d view). An operator class, like when you call bpy.ops.paint.weight_paint(stroke=strokes, mode='NORMAL'), often has a poll function as this one does. A poll function basically checks for certain criteria to be met before running its execute method, and one of the most common checks is if the context is correct. If you are running this from anywhere other than the 3d view in weight-paint mode, the context will likely be incorrect.

Here is an add-on demo (very heavily commented):

# Blank Addon

bl_info = {
    "name": "Blank Addon",
    "author": "Anonymous",
    "version": (1, 0),
    "blender": (2, 76, 0),
    "location": "3D View > Tools > Blank",
    "description": "A completely blank addon ;)",
    "wiki_url": "",
    "category": "3D View",
    }

import bpy
from bpy.types import Scene, Panel, Operator
from bpy.props import IntProperty

# UI...this creates a new panel in the 3D View
class BlankAddonPanel_PT(Panel):
    # name of the panel...
    bl_label = "Blank Addon"
    # used to register panel
    bl_idname = "3D_VIEW_PT_layout_BlankAddon"
    # specifies to make panel in 3D View
    bl_space_type = 'VIEW_3D'
    # it is in the tools not the properties region
    bl_region_type = 'TOOLS'
    # only show panel when in object mode
    bl_context = "objectmode"
    # name of the tab for the panel
    # (if this is 'Tools' it will be on the first tab)
    bl_category = 'Blank'

    # the meat of how to draw the panel
    def draw(self, context):
        scene = context.scene
        layout = self.layout

        # create a new column and label it column
        col = layout.column()
        col.label("Blank Column", icon="COLLAPSEMENU")

        # create a button that is linked to the operator
        col.operator("scene.blank_print_ba", icon="QUESTION")

        # create a property field linked to the prop
        col.prop(scene, "blank_prop", slider=True)

# Operator this is setting up what the "button" executes
class BlankPrint_PT(Operator):
    # the label for the button in the UI (if not overwritten in the panel code)
    bl_label = "Do Nothing"
    # the name of the operator (only used in python ie. for ui)
    bl_idname = "scene.blank_print_ba"
    # tooltip for when user hovers over button in UI
    bl_description = "Prints useless information =)"
    # options: can be registered, support undo (Blender does this for you)
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self,context):
        scene = context.scene

        # this is where the meat of your operator would go :-]

        # send a message to the info bar
        self.report({'INFO'}, "I didn't do anything :-D, but your prop is " + str(scene.blank_prop))

        return {'FINISHED'}

# classes to register/unregister
classes = [BlankAddonPanel_PT, BlankPrint_PT]

def register():
    # register each class
    for i in classes:
        bpy.utils.register_class(i)

    # create props
    Scene.blank_prop = IntProperty(name="Blank Prop",default=1,min=0,max=100)

def unregister():
    # unregister classes
    for i in classes:
        bpy.utils.unregister_class(i)

    # delete props...it's very important to delete each prop
    # you add in register here!
    del Scene.blank_prop

if __name__ == "__main__":
    register()


Is there a way to snap face to the cursor without all its vertices collapsing to a point? I am making a structural latticework, the kind of supports you see on the back of radio telescopes or radar dishes. It is a lot of small struts in triangular and square configurations.

It would be much easier if I could place the 3D cursor where a joint should be, and then make the end faces on the right struts all snap to the cursor.

But when I do that, they all collapse to a single point. It seems like if I do it right, I should be able to prevent that. It is in face select mode, pivot center in individual origin mode.

You are very close.

The selection mode makes no difference.
All you have to do is press ShiftS > Selection to Cursor (Offset).

Or you could Press the Offset button in the tool options (that option is there whether you use "Selection to Cursor" or "Selection to Cursor (Offset)").


How can I parent multiple meshes to one bone? I have a very many objects in my object tree. How can I select them all and parent them to my Root bone?

They are children of the armature, but they're not connected to the root bone.

I've tried to: Press A, Enter Edit mode, Press A again, And then assign the root bone from the vertex group. But somehow this doesnt work, they wont get connect. But when i do it one object at a time, it works...

So, as explained by Jaroslav, the basic way to do it is to switch your armature to Pose mode, then select your object, select the bone you want to parent to, and parent with ctrlP > Bone.

You also have this solution, better if you'll need to join the objects or some other cases, so it really depends on the situation:

First deparent the objects from the armature. If you want to deparent several objects at once, select all your objects, select one last (make it the active one), deparent it, then in the Properties panel > Object > Relations, right click on the Parent field and choose Copy To Selected.
Now select your objects and parent to the armature With Empty Groups, which means that each object will have vertex groups created with the names of the bones, except none of these groups are assigned to vertices yet.
Then select each of your object, go in Edit mode, and in the Properties panel > Data > Vertex Groups, assign to the object the group it is supposed to be part of, meaning the bone it is supposed to be controlled by (it looks like it's the root you want).


How to model an irregular object made of tubes? How can I model this irregular curved torus shape that is in the back of this dolly? I know how to cut apart a torus but I think what I need is for a torus to be extruded along a curve line.

Objects that are made out of tubes can be modelled with curve objects.

Shift+A> Curve> Bezier
On the curve properties make the curve fill type 'full' and set the Bevel depth and resolution to increase the diameter of the tube and the smoothness of it:

The curve on the left is what it looks like after adding it and editing it's shape in edit mode. The curve on the right is after the above settings have been applied.

You can extrude this curve and edit it similarly to how you would edit a mesh, using scaling, rotating and moving to manipulate the curve handles.

If at some point you want it to be a mesh you can select the curve and choose Alt+C> Mesh from Curve


Emitting Light from Object I'm trying to create a semi-transparent wrapper around a light source. This could be gems, brightly lit console buttons, magical semi-transparent glowing fruits, whatever.

Anywho, I tried the approach outlined in another Stack Exchange question (transparent BSDF wrapped around an emission source), but the effect looks quite different from theirs. See the image below. I noticed in their example .blend file there was a field labeled "normal" applied to the transparent shader node that doesn't show up on mine. Is there a step I missed?

It should look like this:

The post you linked to is using a translucent shader, you are using a transparent shader.

Transparency vs. Translucency

Transparency simply lets light pass through the object, only changing the color and intensity.  Translucency lets the light through as well, but it scatters the light on the opposite side from which it struck the surface.

Translucency and transparency are the two basic types of transmission, they are akin to diffuse and glossy in terms of reflection.


How can I access the video editor? I just downloaded the software and don't know how to get to the video editor. All I see is a 3D maker or something.

Use one of the preset layouts.

On the top menu change from default to video editing:


How assign different material to strokes in grease pencil mode How can I assing different material to strokes? I was drawing strokes (see picture) using material named "face1" but want to change it to material "face", how can I do it? Or the only way is to to redraw entire image?

You can do this by selecting the stroke(s) you want to change in edit mode. After that, select your material "face" in the "Material" tab then click on assign just below.
Or go to the stroke menu -> assign Material.


Is it advisable to update Blender to the newest version as soon as possible each time? I know Blender is free software and bugs happen. But my question is, is it good practice to update Blender every time there is an update? Even if a minor one? (i.e I'd consider 2.56 to 2.56b minor or even 2.63, no?)

I haven't been updating very often for fear that updating frequently causes issues like broken settings, non-compatibility or lost user configs?

Or is updating often recommended to keep up to date and adapted to the new changes, i.e like upgrades in the GUI and functionality?

Blender is very compatible between versions, both backwards and forwards (with the exception of the upcoming 2.7, which is supposed to have minor compatibility breakage).
For lost configs, Blender should prompt you to use your old config after you start the new version, but if it doesn't it's very easy to transfer (and keep backups, etc.). See this post for details.
The a and b releases are relatively minor bug fix releases usually only released when major bugs are found shortly after the initial release. In spite of being relatively minor releases, you probably want to use them instead of using the previous release (which has some bug bad enough to justify another release).
Conclusion:
It is of course up to you, depending your habits and what works for you, but I highly recommend staying with the latest stable releases. However, expect to find bugs if you use any development versions.
Notes:
Some extra information you may find useful:
Multiple versions:
You can have multiple versions of Blender installed simultaneously, which may be of use if you want to try the new version without removing your current version.
To install another version along side your current version:

Download blender using the archive (*.zip, *.tar.bz2). The archive gives you a completely portable version of Blender which you put and run anywhere (even a USB drive) without any installation.

Extract the archive into some directory (the archive extracts into a new subdirectory).

Run the blender executable located in the extracted directory.

Note that portable Blender will use the config of the system version of Blender (if there is one) by default. If you want to have separate configs, create a directory called config in $directory_from_extracted_archive/2.69/ where 2.69 is the version of Blender you extracted.
Bugs:
If you do find a bug, report it! The developers are usually very responsive (I have had reports fixed within a couple of hours).
Don't assume someone else will report it if you don't (but do check to see if it's already been reported before you report it, just in case).


Having issues moduling zootopia style fur Ive heard that Blender was capable of producing Zootopia style fur on characters using the participial system. Well sadly there doesn't seem to be many guides on fur. The few ive found use a ball or a flat plane to show how it works but don't apply it to an actual character

This head I made incapacitates all of my issues

I set a vertex group for every part of the head I wanted to add fur to and left out parts like the nose eyes mouth and inner ear yet when I add children it bleeds over into those parts. Ive tried combing the strans as far away as possible and cutting the parent hairs around the bald areas but they just keep bleeding over.

I don't know whether or not to use more parent hairs with a hand full of children or very few parent hairs and populate the area with mostly children
You can see the hairs clipping though the normal's for two sided areas like the ears

The hairs look like these gross cone shapes when viewed closely
How can I make sure the fur is distributed evenly across the head? There are these weird random bald spots.

I am kind of where you are right now. I can give you some input maybe.

There might be a better way but a workaround at least is to duplicate the parts of the mesh and then separate them into a new object. That way you won't get hair in areas you don't want it. You can hide the emitter, so you only see the hair.
It will probably look better if you use more parents and less children.
Might be okay if you do it like answer 1.
You can set the thickness of the hair at the root and the tip. Yours is probably still set to 1 at the root. Try lowering it to 0.25
I am not sure, maybe related to question 2.


render frames stuck at single frame but frame no. goes on I decided to render an animation and when I put it on render after 2-3 frames
Cycles stuck on rendering single frame every time and just no. keep on increasing.

Cycles keeps rendering the same image over and over again rather than following the animation.

I'm using

Blender 2.8
i7 8750H
1050 TI 4GB

Could be bugs. I experience that when using SkyTexture for the environment, it just sticks on rendering frame 1. Changing environment to an other background like HDRI solved my problem.


Is it possible to control the bounciness in Rigid Body? I was trying to make 3 balls bounce at a time from same height with same weight and same bounciness. But when they collide with the passive surface they start to bounce unevenly like one goes very high other one bounces very low and gradually they change direction while bouncing.

I noticed it was a bug in Blender 2.8 Beta. Later it worked properly.


Animation nodes performance I've been messing around with animation nodes to influence materials in an array of 1500 cubes, creating a simple motion graphic from a simple node tree.

I've attached the blend file for reference.

I started using an object instancer to create the array but the program became bogged down with too many instances (it seems to start afresh after each time i stopped execution to make an amendment, without deleting previous instances first) so i created the array first and modified the node tree to work on a Collection instead.

The problem i have is that animation nodes seems incredibly slow for a relatively simple node tree and modest collection of objects.  The simulation runs at over 4 seconds per iteration and the screen is incredibly laggy - it takes an age for Blender to recognise when i click 'auto execution' off to make a change.  It also takes a while to load the file in the first place.

In addition to the above, Blender crashes after rendering 15 to 20 frames meaning i had to render the whole 300 frames in small chunks.

I have a reasonably heavy-weight system - i have an i9-7900X, 32Gb RAM and 2 x Quadro P4000 GPUs.  The GPUs do all the heavy lifting on rendering but the processor hardly breaks sweat at about 18% utilisation, with memory peaking at just 150Mb.

My question is: why is Blender making such heavy weather of a simple node tree?  And if it does involve a lot of processing, why isn't the CPU used more intensively?

Any light you can shed would be appreciated as AN is almost unusable at the moment.

Try to avoid calculations inside loop if we can do it directly, most of the AN nodes are vectorized, which can perform faster than using loop. So we can modify node tree to something like this:

We can completely eliminate loop by replacing Set Vertex Color node with Object Color Output node since object have only one color and by using Combine Colors node instead of  Mix Colors.

If you have stability or crash problems you can inform developers by creating an issue here


Trying to make character for UE4 - Need guidance I have made a knight character, and I want to give him a skeleton to throw him in UE4, though I have a few things making that less than simple. Mostly, I want to be as accurate to an existing skeleton as possible (the default UE4 skeleton) but importing that into Blender has some major issues.

So I've started making my own skeleton as close to the UE4 one as I could, I've got UE4 on my other screen. I don't know about a couple of things. First, there's "twist bones" on the upper arm and upper leg, as well as a "root". I don't know how those should look, or if I even need the twist bones (I know I need the root).

I need to know:

What do I do for the root?

How can I mirror what I've done  to the other side?

Can I do without the twist bones?

Strangely I can't find much if anything for making armatures specifically for UE4, or without using Rigify, so maybe I'm just doing it wrong. I could use some guidance.

Here's the hierarchy I've got so far, it perfectly matches UE4.

And just for fun, here's what I'm trying to get animated.

Help and advice greatly welcome and appreciated.

Found an Answer that actually works just right:

Export The UE4 mannequin.

Remove anything you dont want to use including MESH, IK bones, Twist bones.

Turn on snap and set it to verticies.
Then grab ends of bones that are in the wrong positions. Move them using the axis arrows onto the correct bones.
Save it for next time as it's own file

Next bring in your mesh. Scale appropriately for unreal
In object mode, select the skeleton. Press shift+C so that you scale from origin. Scale it to your mesh.

Turn on the mirror x and move bones as needed.

In object mode, select the mesh and skeleton and press CTRL+P
set them by weight when asked.

Go into weight mode and fix all the crazy stuff it will do for whatever reason.
Export to unreal.

In unreal make sure you dont choose a skeletal mesh during import.
Open the UE4 skeleton. Get to the rigging options and set it to the humanoid rig

On your skeleton do the same thing.

Go find whatever animation you want, right click on it.
Select Animation re target asset, and in the process just choose your skeleton.

Skip all the rigging stuff in blender.
Where i was having problems was the weighting. I didnt realize when I would just parent the unreal skeleton to what was basically an unreal model with some clothes on it that i was choosing some CRAZY weights.
I was able to fix them fast by setting the weight tool to subtract, full power zero fall off and going through each bone and drawing over the whole model that WASNT obviously supposed to be connected.

I did over do it a bit, but the system is kind enough once it was all set up i could have UE open and blender, modify the weight and export. UE will process the changes and instantly show them in the animation window I had open.

(I had a beltbuckle attached to right pinky, left pinky attached to right ball, all sorts of pieces of the shirt attached to random parts of arms, the spine 1 was the whole torso and the rest of the spines connected to random parts of shit/buttons on shirt etc.

Now i am on to fixing the duster so it doesnt go through the characters legs and it's acting all funny around shoulders when character lifts arms...

I dont do anything to the Root. And the pelvis is in the right position/size.
just get it connected to the spine.

When you do export the FBX you need to go to the settings on left, click in the armature section and untick add leaf bones. Otherwise it adds extra ones to the fingers and such.

Inside unreal the skeleton will have 2 roots. There is a file somewhere supposedly that will fix the export of that. But the links I had to it were either dead or only worked on much older Blender versions.
I found you can click on the highest one in the skeleton mesh asset and right lick, disable from LOD 0 and below. It still shows on the list but isnt connected to anything any more and isnt used.

I put my empty rig FBX here: https://drive.google.com/open?id=1lq1SBXGq9485KXKbYENgI-sEMUeUCUGN


How to create a luminous led fabric I'm having trouble creating a bright LED fabric, can someone give me a way

I used this setting to create the led, but it wasn’t like the picture

I know there's a better way to do this, but I only took a few minutes.  Hopefully it gets you started.


Is there a Blender api to fill a color to a certain vertex_colors? Taking a cue from this question, I'm testing to make a one-color fill to a vertex_colors.
Works fine, but is very slow on meshes with many polygons.
ob = context.object
color = (0,0,0,0)
vertex_color = ob.data.vertex_colors['My Vertex color']

i = 0
for p in ob.data.polygons:
    for idx in p.loop_indices:
        vertex_color.data[i].color = (color)
        i += 1

I also found an operator,bpy.ops.paint.vertex_color_set() (It seems to be twice as fast)
but I don't really like the idea, plus it's an operator with no input apparently
Is there any blender Api that do this directly?
After a good answer:
The code above is code that doesn't make sense in this case.
My tests moved to this method (Not very fast):
for d in vertex_color.data[:]: #Slow method
    d.color = (1,0,0,1)

In any case, given @batFINGER answer, and @lemon help, the code is now 4 times and more, faster than before.

Set all loop vertex colors to one
Use foreach set method. Example of use here creating bezier curves https://blender.stackexchange.com/a/180184/15543
import bpy
import numpy as np

context = bpy.context

name = "Xxxx"
r, g, b, a = (1, 0, 0, 1) # red

ob = context.object
me = ob.data

color_layer = (me.vertex_colors.get(name)
               or me.vertex_colors.new(name=name)
               )
ones = np.ones(len(color_layer.data))

color_layer.data.foreach_set(
        "color",
        np.array((r * ones, g * ones, b * ones, a * ones)).T.ravel(),
        )

me.update()

Could also simply
np.array((r, g, b, a) * len(color_layer.data)).T.ravel()


How to save a node setup for easy access in default scene How can I save a node setup, such as procedural texture, so I can easily access it in my default scene. It would be a great help to not have to import or start fresh each time.

That's one use case for Node Groups.

Select all relevant nodes and group them with Ctrl+G. This way the created group is accessible within all material node trees, located in the Add menu: Shift+A > Groups > Your Group Name
Save your config as well as the created node group as part of your Startup File under File > Defaults > Save Startup File


How to add armature controls? First of all, I am really new to Blender so the question might seem dumb but I couldn't find something in the internet.

I've just finished rigging a character with all the bones. My question is how you can add bone controllers (the yellow cube, all the circles and arrows) like in the picture below.

I only find tutorials explaining how to add bones or link them to the mesh.

I am really happy that there is such a great Blender community. Thanks in advance.

These bone controllers are in fact extra bones themselves.

In Blender, controls for a rig are usually implemented as bones in that rig with the deform checkbox disabled (this checkbox tells the armature modifier to whether to consider a bone or not for calculating the mesh deformation). The rigger will then make use of various constraints to define how they control the deforming bones in the rig.

Control bones often use custom bone shapes to give each controller easily recognisable and understandable shapes. These shapes are defined other meshes that have been hidden away somewhere in the scene (on a hidden layer prior to 2.8 or in a hidden collection (2.8+)). Unfortunately Blender does not come with an easy to use library of these, although the Rigify addon will generate quite a few if you use it to generate a rig.


Materials, textures and how they relate to models before/after render I am brand new to Blender and just want to confirm that I understand the difference between models, textures and materials (particularly the last two).

My understanding (please correct me if I'm wrong!) is:

A model is the mesh of the 3D object (contains 3D coordinates of each vertex, and all the edge information between connected vertices). There are multiple file formats for models (PLY, OBJ, etc.) and Blender supports most of them.
A texture is a file that contains 1+ 2D images representing the surface of the model. Textures get mapped to the outermost vertices of the model and provide (primarily) sub-polygon color details, giving the models (essentially) their outward look-and-feel. There are also multiple file formats that can store textures since they are essentially containers of 1+ images (but what file formats are there?)
A material is a collection of light properties on each pixel or polygon (which one?) on the model. Materials determine what happens when light (and only light - nothing else) strikes the pixel/polygon at a specific angle, with a specific intensity, etc. Materials can either be baked (pre-rendered) into a texture, and subsequently exported/saved as a texture file. Or, materials can be exported/saved as a separate/third file type; I believe MTL files are material files.
Rendering is the process of baking materials into textures, and then applying/mapping the baked textures onto the surface of models, and producing a 2D image from a specific camera position/orientation.

How'd I do?

You got most everything right but there are a few misconceptions there.
Model
A model is the geometry giving shape to a 3D object, it is often of Mesh type but may be also composed of other geometry types, like Curves, Text Objects, or less commonly in Blender NURBS. It may also comprehend other animation related data like rigging, shape keys, and armatures.
The formats you speak of have nothing to do with models themselves, though they serve as way to export them. They are mostly interface file formats useful for transferring data between different applications, Blender does import and export most of them, but to faithfully save your data you must exclusively save in the native .blend file.
Texture
Textures are for the most part regular 2D images as in jpeg, png, tiff, tga, EXR image files. They are just a name for an image that will be controlling a property of a material, it is not a file format that contains "1+" images, it is an image. They simply describe color information, they hold no information regarding surface properties of an object themselves, and can't be used alone for the most part, but can however through a material serve various purposes like provide actual diffuse (visible) color of a material, or other surface properties like roughness (bump or displacement maps), shininess (glossiness or reflectivity), emission, and many other properties.
There are two main types of textures, actual image textures, as described above, using an image file, or procedural ones, generated by the rendering engine (generally can't be exported or used elsewhere outside the source program).
Material
A material is the collection of image textures, procedural textures, shaders, and surface/volume properties that describes the final appearance of the surface. It may include reflectivity, lighting, color and/or volume information. Materials can under certain circumstances be baked into a "static representation" of the surface for export, but are otherwise for the most part not exportable
A material can use any number of textures or none at all, and an object can have any number of materials (except for certain game engines). Materials are assigend to objects using Material Slots but only one can be assigned per face at each time. Of course using too many textures and/or materials may have a negative impact over performance of a scene or rendering.
Rendering
Rendering Is generally used to refer to the process of transforming a Scene (composed of 3D models with Materials) into a 2D image (like taking a picture with a camera). The process of transforming materials into textures, although also achieved through the same rendering process, is generally referred to specifically as Baking. Just to be clear, baking obligatorily involves rendering, but rendering doesn't necessarily require baking.


Any way of serializing Blender cycles materials data? I am searching of ways to serialize Blender Cycles materials to files using Python. But as of now I've found no such ways.

Maybe by writing the data of the materials to files but how can I do that? Even the slightest of contributions are appreciated.

If only there was a way to serialize materials to JSON/Binary/XML.

Perhaps someone here can lead me to light.

Maybe in the way Blender stores the materials?

There is the rna_xml module, which produces pretty verbose xml

from rna_xml import rna2xml

rna2xml(root_node="MyRootName",
        root_rna=bpy.data.materials['Material'].node_tree)

produces (not full output).  There is also an rna2xml routine.  To output to a file use rna2xml(fw=f.write, ...) where f is a file.

<MyRootName>
  <inputs>
  </inputs>
  <links>
    <NodeLink is_valid="TRUE"
              from_node="ShaderNodeBsdfDiffuse::Diffuse BSDF"
              to_node="ShaderNodeOutputMaterial::Material Output"
              is_hidden="FALSE">
      <from_socket>
        <NodeSocketShader name="BSDF"
                          identifier="BSDF"
                          is_output="TRUE"
                          hide="FALSE"
                          enabled="TRUE"
                          link_limit="4095"
                          is_linked="TRUE"
                          show_expanded="FALSE"
                          hide_value="FALSE"
                          node="ShaderNodeBsdfDiffuse::Diffuse BSDF"
                          type="SHADER"
                          bl_idname="NodeSocketShader">
        </NodeSocketShader>
      </from_socket>
      <to_socket>
        <NodeSocketShader name="Surface"
                          identifier="Surface"
                          is_output="FALSE"
                          hide="FALSE"
                          enabled="TRUE"
                          link_limit="1"
                          is_linked="TRUE"
                          show_expanded="FALSE"
                          hide_value="FALSE"
                          node="ShaderNodeOutputMaterial::Material Output"
                          type="SHADER"
                          bl_idname="NodeSocketShader">
        </NodeSocketShader>
      </to_socket>
    </NodeLink>
  </links>
  <nodes>
    <ShaderNodeOutputMaterial type="OUTPUT_MATERIAL"
                              location="300 300"
                              width="140"
                              width_hidden="42"
                              height="100"
                              dimensions="178.889 116.333"
                              name="Material Output"
                              label=""
                              parent="NONE"
                              use_custom_color="FALSE"
                              color="0.608 0.608 0.608"
                              select="TRUE"
                              show_options="TRUE"
                              show_preview="FALSE"
                              hide="FALSE"
                              mute="FALSE"
                              show_texture="FALSE"
                              shading_compatibility="{NEW_SHADING}"
                              bl_idname="ShaderNodeOutputMaterial"
                              bl_label="Material Output"
                              bl_description=""
                              bl_icon="NONE"
                              bl_static_type="OUTPUT_MATERIAL"
                              bl_width_default="140"
                              bl_width_min="100"
                              bl_width_max="320"
                              bl_height_default="100"
                              bl_height_min="30"
                              bl_height_max="30"
                              is_active_output="TRUE">
      <inputs>
        <NodeSocketShader name="Surface"
                          identifier="Surface"
                          is_output="FALSE"
                          hide="FALSE"


Fluid Simulation is still low quality even with resolution of 250 I am trying to make my fluid look realistic but it isn't smooth even with the quality set to 250.

I have uploaded a video of it here:

https://www.youtube.com/watch?v=E54ObJrXHiM

Is there any settings I should change?

I changed the viscosity to these settings:
Base: 10 | Exponent: 3 | Domain size is also: 3m

Smoothing: 2 | Subdivisions: 2

Simulation Speed: 0.08

Here is a close up:

http://s24.postimg.org/vvq2ryhtx/fluid.png

For one thing, a resolution of 250 isn't that much. Everything will look crappy at that resolution. And as gandalf3 said, make sure your domain isn't unnecessarily large.

Setting subdivisions to 2 won't really improve your simulation in this case. Change it back to 0 (or 1, because of blender logic it is the same) and save some baking time.

For extra smoothing, use the smooth modifier. However, it may reveal holes in the fluid mesh, so make sure you check what's going on before you render.


Best way to paint same Material with different mask? My question is to have an alternative way if it exists.
So my problem is the following:
As you can see from this image, I have 2 materials, the first in the top row, uses vertex paint, so white and black decide how to mix green and red, so everything is ok here.
In the row below, there is a material practically the same, but which uses a mask (Always black and white) for vertex paint which is absolutely more detailed, as it does not need to have a high subdivision of polygons (As in vertex paint) .
But there is a problem in Texture paint, unlike vertex paint, that is, the possibility of painting the same material on many objects, without these being modified all together, let me explain better,
The vertex paint refers to the colors of the vertices of the object, but is very limited on the final results, due to the triangulation that is very visible, but remains independent (If the object is not an instance)
The texture paint is very nice, but it does not remain independent, so if I paint an object, the other object with the same material will suffer the same fate, therefore I will have 2 objects with the same mask.
I'm trying to approach this to understand which way to go, without having to create a new material, but probably my knowledge stops here.
Basically, I would like to have only one material, with the possibility that it can be masked independently on objects.
I would also like a vertex paint solution, if this were not so "Squared". I have a lot of confusion right now and I would like to know an answer on this, which will guide me to a "Logical" but intelligent choice, always keeping the single material

Post Bounty Note:
Based on Splize's answer , however, I thought that this method could contrast with the real use of Index pass? but actually it seems a very useful answer, and it works very well. At this point I would like to understand if there are further way that can be taken. Taking into account also a hypothetical more detailed vertex paint, because the vertex paint is much more "comfortable" as it does not require an additional Mask and "Smart Projection" to make the correct mask mapping

You will have to specify some kind of "mask" at some point of process for any object. So I'm not sure if the shared material is key for you.
If you want just be able to change node-tree shared by multiple objects from one place you can use Node Groups. Place all material node-tree into a group (Ctrl+G) only "mask" node and Material Output place out of this group.

Once created, the node group can be placed (Shift+A > Group) everywhere and managed from any of its copies. This way you can completely change node tree into totally different look without touching material with mask specific to object.


Problem faced while doing re-topology - can't maintain quads While doing re-topology I ran into a problem. I can't made quads. It seems really hard in this region.

A few things I am trying to maintain to achieve a better topology:

Make it quads.
Try to make individual quads mostly of same sizes (approx).
I am adding more loop cut where I know it would tweak the muscle during rigging.

I don't know how I would continue without violating the first point from my guidelines.

Quick Aside: I find it easier to work from general to detailed when doing retopo work, doing the details and then trying to stitch them together means you lose control over the general topology flow because you are trying to reconcile your dense detail loops.

One of the first things you learn doing subdivision surface modeling is that you will need to cheat occasionally.  You will have to break one of your tenants every now and then, and knowing when and where is one of the primary ways to grow as an artist.  So, some suggestions:

(Addition) One of the things LukeD was trying to point out with his comment and that I missed is that you want your mouth to be the radial anchor for the rest of the face.  This means that the concentric topology loops should be drawn from the mouth.  This allows for the least amount of unnatural deformation when posing the mouth and lips.
If you want to preserve your flow, you should just extend the poly rows to the rest of the lip and have them converge at the lip's taper.  You would also keep your polys as quads, but they will be very small.  This is generally how it is done, see Polycount's face topology examples .
From experience, I would at least consider breaking the flow near there to deform in a collapsable way.
You could also entertain putting a loop reduction quad there as well.
(edit) This is an arrangement of polygons that reduce loops in a way that allow high detail to low detail transitions, and look like such:   Source of picture and a great guide to using them effectively here:  http://topologyguides.com/post/163679954765/loop-reduction


Trying to create a simple add-on but Python keeps throwing errors I am trying to create a simple add-on that will automatically reload images in Blender. I managed to find a few scripts that helped me and when I press "Run Script" it works as expected. However, when I try to add it to the Add-On in Blender, I get this error:

  AttributeError: '_RestrictData' object has no attribute 'images'

The line causing the problem is:

images = bpy.data.images

Here is the full script:

import bpy
import os
from threading import Timer

bl_info = {"name": "Auto Reload Addon", "category": "Object"}
last_mod = {}

def startup():
    images = bpy.data.images
    for img in images :
        if img.source == 'FILE' :
            path = img.filepath_from_user()
            statbuf = os.stat(path)
            last_mod[img.filepath_raw] = statbuf.st_mtime

def autoreload():
    images = bpy.data.images
    for img in images :
        if img.source == 'FILE' :
            path = img.filepath_from_user()
            statbuf = os.stat(path)
            if statbuf.st_mtime > last_mod[img.filepath_raw]:
                last_mod[img.filepath_raw] = statbuf.st_mtime
                img.filepath = img.filepath.replace('\\old_folder\\','\\new_folder\\')
                img.reload()

def register():
    print("Auto Reloading Enabled")
    startup()
    rt = RepeatedTimer(1, autoreload)

def unregister():
    print("Auto Reloading Disabled")

if __name__ == "__main__":
    register()

The RepeatedTimer is a class I found online that run a function every X seconds

I searched online and The kinds of solutions I saw is to use bpy.data after the register(), and it didn't let me call it like this:

if __name__ == "__main__":
    register() # This is called
    startup() # This wont even be called when the Add-on is enabled!

I understand that this has something to do with the import but I can't figure out what is wrong. I tried a few things that didn't even run.

Am I doing something really wrong here? again, the "Run Script" button works as expected, but I want to be able to disable and enable the script.

You cannot access Blender from a different thread. To create a periodically called function, use a modal operator with a timer.


Give this mesh a uniform thickness on all the tubes and unions I am trying to create a 3D model of bone marrow, that is composed mainly of a lot of random tubes, creating a volume.

I found a 3D scan from some bones, and thought I could save a lot of work just cleaning them up, but I can't find a way to leave them on a constant thickness and roundness, the best I can achieve is this ugly thing.

Any ideas on how it can be done? Thank you in advance!

Edit: Done! After playing with it a good amount of time, I got something I like with the Sverchok add-on. I've left a screen of the render (just need a better texture for it to be ready) :D

You can create similar results using a procedural volumetric material similar how you would render smoke but with a much higher density to simulate a solid diffuse surface.

To create this, start with a mesh to act as a 'domain' for the volumetrics (eg, a Cube) and create a 'standard' volumetric Absorbtion/Scatter material node set up with a high density.

To demonstrate generating a volumetric surface within the domain volume you could start by using the Dot Product of the Object coordinates to control the density based on the distance from the origin to produce a sphere. To improve the quality of the rendered surface you may need to reduce the Step Size in the Volume Sampling properties panel - smaller values will produce a smoother surface but will increase render times.

The volumetric material absorbs a proportion of the incident light resulting in a darker surface than you would expect with a Diffuse shader. To correct for this, inclulde a MixRGB node set to Divide to divide each channed by 0.2 to effectively "multiply up" the brightness of the surface by a factor of 5. This adjusts for the light lost by the Absorbtion/Scatter.

To create a cylinder, calculate the distance based on any two of the X,Y,Z channels - X and Y for a cylinder along the Z direction, Y and Z for a cylinder along the X direction, X and Z for a cylinder along the Y direction - using Pythagorus theorum a^2 + b^2 = c^2 .

For an array of cylinders use Modulo Maths nodes to generate distances from a series of centrelines. For example, for lines spaced at 1 unit apart the distance from any line (placed on each integer x coordinate) can be calculated as :

distx = abs(mod(x, 1)-0.5)

Apply this to the coordinates of the two dimensions used to generate the cylinder, repeat for each 'direction' of the grid and use Generated coordinated and a mapping node to allow the number of cylinders in the grid to be easily controlled via the Mapping 'Scale' :

Using additional Maths nodes to combine the three arrays of cylinders allow the intersections to be blended into each other by allowing each cylinder to influence the surface by proximity. Here they are combined using the reciprical of the square ("1/(dist^2)") so that the closest line has the greatest effect with the influence falling off as the distance to the neighbouring lines increases. Adjusting the factors for the Multiply, Divide, Greater Than varies the width of the branches and amount of 'blending' between the cylinders to get the desired result,

To add some variation we can use a Texture to affect the presence of each 'branch'. Care needs to be taken to calculate a 'coordinate' of each branch by 'truncating' each coordinate using Modulo functions (eg, to truncate x down to the nearest 1.0 use 'x - modulo(x,1.0) - this can then be passed to the texture so as to affect the entire length of that branch :

Finally, add some distortion by manipulating the original coordinates - in this case with a Noise texture (see full material below).

Bring it all together to create the following material :

Adjust the highlighted nodes to adjust the line thickness, pruning of branches, and distortion.

Blend file attached

Note : Care needs to be taken with the setting of the Volume Sampling settings (renamed to a 'Geometry' panel in newer versions of Blender). The Step Size indicates how far a ray should travel through a volume (in World coordinates) before being re-evaluated. Larger values will produce a faster render but sacrifice quality, while smaller values will produce more accurate results but will take considerably longer to render. The Max Steps parameter determines how many such 'steps' can be taken through a volume. For a 'see-through' volume (ie, where the branches are quite thin so light can travel right through the volume) you should set this to a value high enough so that the Step Size multiplied by the Max Steps is at least as large as the size of the Domain mesh - otherwise generated volumetric geometry may be clipped. If, however, the branches are thick enough to ensure there typically isn't a visible path through the domain, you may be able to set the Max Steps smaller without causing issues as rays would not be able to pass so far through the domain. The image at the top of the answer was rendered using Step Size of 0.002 with 1024 Max Steps.

Also note that Volumetrics are not normally affected by the 'World' illumination unless you enable Multiple Importance Sampling on the World - see Volumetric Scatter ignoring World lighting


Mesh issues after using boolean modifier I've been following Blender Guru's anvil tutorial, and although I have a (seemingly) ok mesh, the subdivision modifier isn't  working correctly, as I get a hard seam where the area carved out by the boolean modifier is. I've attached the Blend File below if anyone would like to take a look at it. Thanks

I downloaded the .blend file, and it seems you just need to recalculate the normals on the areas carved out by the boolean modifier. There's also a stray edge near the base of the anvil that's creating some ugly topology. Remove that stray edge and recalculate the normals and everything should be good to go!


UV unwrapping gives a skewed result I'm following a small tutorial that includes UV unwrapping. It's for a very simple object that's supposed to represent a bench. The object itself is made by taking a cube, scaling in Edit mode and then extruding the ends to create the legs of bench. When I mark seams and unwrap it, I get a pretty insane, for lack of a better word, result (see image). The most common solution to this that I've found is switching from Angle based to Conformal method of unwrapping, but it does close to nothing. It does change the unwrapped map a bit, but it still very closely resembles the one that I get from using Angle based UW.

I've tried changing up how the model is divided by seams and I do get some slightly improved results, but I haven't managed to get to a point where at least part of it isn't skewed.
Anyone have any ideas? I'm completely stumped at this point.
Thanks in advance!

I suspect your seams are not disconnecting the two sections - possibly you have duplicated geometry. In Edit mode, select all vertices and do a Merge By Distance to ensure you haven’t got overlapping geometry (possibly the result of a cancelled Extrude operation) then check your seams again and re-unwrap.


Is there a way to disable composite effects on already rendered frames? I rendered about ~170 frames with the glare node on and would like to look how the normal render looks without rendering those frames all over again.

Unless you saved the images before post processing, there is no way: once an image has been processed, flattened and saved into an output format, you can't de-construct it and revert it to a previous stage.

  You will need to render again.

But before you do that please read on.

As a piece of advise: you can use a file output node to save each frame as is being rendered before post processing.

Also never render an animation as video. Render an image sequence and encode later.

If you care for quality use OpenEXR as the render format. That way you can keep your information, and passes undistorted and linear.

There is a reason why Post-production exists. If you have saved all of your frames before any effects, then you can brig those rendered frames into the compositor and experiment different looks and effects in a non-destructive manner, without having to re-render the original rendered layers every single time.

Rad: Is there a way to export each rendered layer as its own image?
 and How can I render all render passes to files in Cycles?


How do i make round bottle look more cubic with really soft edges? I am a complete beginer. I was trying to model this 5 liter bottle and then realized it supposed be more squire - like in the included image. How do i do it? No way i can figure it out myself...
I know this model is a mess and not perfectly modeled but it'll do for my purposes. Just need it a little bit squared like in the image...

Start with an octagon
WS Subdivide  a copy of it
Make another copy, and S scale its orthogonal vertices in to make it squarer.
Make a copy of that, and subdivide it, too.
With the copy, instead of subdividing it, CtrlShiftBbevel all its vertices.

When making the variations, they won't be side by side as illustrated: shift them up in Z to keep them out of the way, and vertically lined up. You can ShiftD make copies of those to work with, any time you like.

You now have all the profiles you will need for your bottle, bar a bit of tweaking.

Now assemble the bottle vertically, working your way down by  E sometimes extruding from copies of your profiles, and sometimes using  Ctrl E > 'Bridge Edge Loops' between them.

You can use the shipped add-on Loop Tools > circle to make the profile circular at the neck.

The profiles shown here are: the neck, just above the ridge, and the smooth label area.

The closer the vertices on the profile are to one another, the sharper the crease in the final surface, after subdivision. You can vary the bevel on the squarer profile to achieve that. This example has 2 levels of Catmull-Clark, in a  Subdivision modifier, and the profiles are shown with the subdivision.


I'm trying to follow a tutorial in youtube but i don't have a bolt mesh . What should i do? The tutorial is in this link: tutorial

In minute 9:46 he is adding a bolt: Add > Mesh > Bolt
But i don't have any bolt mesh in the menu or sub menus of Add > Mesh

I saw someone else added comment about it but not one gave him answer.

Enable the Add-on "Bolt Factory" in the user preferences.


Making a printable half sphere with a cutout in it for 3D printing I made a half sphere which prints nicely. The sphere is to be used as a stencil for marking your golf ball.

I used the Knife Project to cutout the F.  This however created a lot of non-manifolded edges, which are not printable.

How can I cut out the shape and still preserve the mesh?

Once you've deleted the face you can extrude your object to give it thickness, or give it a Solidify modifier then apply. If there's already thickness you could extrude your F and use a Boolean modifier on your half-sphere.


How would I setup a model for use with SSR in another game engine? I'm attempting to use Panda3D with an extension for PBR. However, upon exporting my model, the default Blender enviroment map is put in somewhere, this causes it to reflect off of the grassy plains that Blender shows by default. I am attempting to change this.
My main question here is: How do I export without using a baked in enviroment map?
The research I've done indicates that somewhere Blender is baking in the enviroment map as (rather then an issue with my code):

Models with some sort of SSR option on (I have no clue what it is) work as normal.
My models (I tried with a simple metalic cube) don't work, reflecting off of the afformentioned world.

Googling the issue turned up nothing. Can anyone help? Thanks.

Turns out it was working, just not in the way one would think.
So, basically, what was happening was that it was not only reflecting off of the default world, but also onto the in game world. I didn't look close enough to notice, but that's what was happening.
In order to "fix" this, you need to set the enviroment map to an empty white (or black, or any other color for that matter) so that your true reflection will be overlayed on top.


How to animate camera around a water simulation? I have just created a water fountain with a water simulation creating the water sprouting out. I would like to Animate the camera around the water fountain while it is flowing water from its sprout.  I have tried key framing all the movements but they do not register, and I just end up with a stationary shot of the fountain sprouting water.
Can anyone help with how to set this up to work, or point me to a video on the technique.

The easiest way to control a camera is to use a curve object:

Create a Curve object and modify it as you like. This will be the path where the camera will move
On the camera create a Follow Path constraint, set the curve as the Target, and you might want to tick the Fixed Position checkbox
To make it easier to control the camera direction, create a new empty (I like the sphere one)
Add a Track To constraint on the camera and set the empty as Target. The orientation is To: -Z and Up: Y
To animate, create 2 keyframes on the Offset slider in the Follow Path constraint

This way, when you change the Offset value the camera will move on the path, and it will always look at the empty.
In your case, put the empty on the water simulation and shape the path as a spiral around it to get a beautiful cinematic camera animation. (The empty can be animated as well if you want)


About the version of blender written in bl_info When developing an add-on, I write bl_info as follows.

bl_info = {
    "name": "test_bl_info",
    "author": "taichi",
    "version": (1, 0),
    "blender": (2, 80, 0),
    "location": "3DView",
    "description": "test",
    "warning": "",
    "support": "COMMUNITY",
    "wiki_url": "",
    "tracker_url": "",
    "category": "Object"
}

And I distribute add-ons to users.

But will users have to rewrite this bl_info every time a new version of blender comes out?

Is there any way that bl_info is automatically rewritten according to the Blender version that the user is using?

The Blender version in the bl_info should indicate the version of Blender it was written for. Future releases of Blender may change the API and the version information can be used to perform a simple check whether the add-on may work with the Blender release. Blender 2.8x already displays a warning when an add-on with blender lower than (2, 80, 0) is installed. Automatically updating the value of blender would therefore defeat its purpose.


Microdisplacement "on" in the middle of a large project What would be the effects of enabling microdisplacement in a large project that is already exists - and using it for new mesh items that are added/adjusted/replaced?

I haven't played around too much myself with microdisplacement, but it sound like what you want to do should work. You will want to make sure you also have adaptive subdivision set to get the best performance. You may still want some of the displacement to come from the displace modifier though, this will require a bit of testing to see what works best.

With remeshing, you may instead want to look at the unsubivide setting on the decimate modifier if the scene was created with applied subdivision modifiers, you will end up with better topology for subdivision.

If viewport performance is the main consideration, you may also want to take a look at the simplify settings under scene properties. It give you the option to control the maximum viewport subdivision for all subdivision modifiers.


Camera moves location when rendered. Why? The final render is different than the camera view previous to rendering. Not sure where I went wrong.
This is the camera view (below)

This what the render spits out (below)

camera settings

dimensions

Through my detective work I've figured out that the butterfly object is the problem. I appended it from a previous file into this one and that's when the render messes up. I've tried starting a completely fresh file and and rendered the basic cube and the camera was perfectly fine. However, once I dropped in the butterfly it gets wacky. Any help would be appreciated!

Without seeing the file, I kind of don't think it is an object (butterfly) problem. My guess is that you have different viewport and camera focal length and/or shift settings (make them the same). Maybe you have lock camera to viewport on. Turn that off (in the right side tabs).
Also maybe instead of appending try opening both blender files in separate 'blenders', and then copy/paste the butterfly object rather than appending. You might be appending some subtle thing that gets pulled in by the append functionality.


How to make curve closed? How can I close a curve / path / to make it closed shape ?


How should a glass material be setup in Cycles? A glass-shader produces a render like this:

Adding a transparent shader creates

Where does the border labeled as 1 come from? Why is the outer region (2) more translucent than transparent?
Not sure this is a material or lighting issue.

.blend

With out a subsurf modifier it looks terrible:

I tried several values from the IOR range 'Glass': 1.440 - 1.900

Only the upper edges and bottom are beveled.

There are a couple things going on here:

The glass is not entirely white, so a noticeable amount of light is being absorbed. Setting it to white (or almost white) gives a more glassy result:

With a less uniform lighting/environment the glass is more visible:

In this render I adjusted the model to get rid of the subsurf artifacts and thicken the bottom a bit.
There is an air gap between the liquid and the glass. This isn't the way liquid normally sits in a glass in real life, so it might look funny. See Liquid / glass interface IOR and normals in Cycles.

If the interface between the liquid, air, ice, and glass are setup as described, you get a result like this:


Path Constraint deforming Mesh I just finished the walking cycle for a Horse inspired model and tried to apply the Follow Path Constraint which caused a weird behaviour:
The armature follows the path but the mesh stays put, deforming more and more as the armature moves away from its starting point...

What am I missing?

for stability I don't allow bones to follow paths.  Instead I use an 'Empty' or dummy invisible 2D plane and parent the main armature to that, then have the dummy follow the path.  You could try that.

It's an easy matter to vary the main armature's attitude/rotation/pitch etc without having to worry about any interaction the path constraint might have.  I don't recall ever having problems varying individual bone movements either.


How to make a plane that has been deformed straight? Currently working on a car for a game and I want it to be low poly kinda like the one below.

The problem is that I made it using a flat plane and then used the edit mode to move and cruve them into place so now my hood looks like this:

Please help D: All I want is to make it into a flatter surface with less dents and bumps!

Try scaling with a value of 0 on an axis, that will straighten it for you.

Maybe try all three axis and see which one will fix it  (S, X, 0, Enter ), also try the Z and Y as well .


Is there anyway to make blender print errors in the UI? For some reason, sometimes error messages encountered while scripting are not printed in the info panel, only the message Python script fail, look in the console for now....

One question I have is:
Why is this?

I like working with blender full screen, but it gets annoying having to switch back and forth between the terminal and blender while scripting.

Is there anyway to print stdout and stderr (I assume that is where blender is printing these messages) in the UI? (thus also solving the occasional necessity to restart blender because of not starting it from the terminal)

So my other question is: How can I do this?

I realize that this is technically two questions, but they seemed too related to separate.. I'll separate them if it's better that way.

I created a little utility addon that let's you easily run Text datablocks of your .blend (doesn't need to be saved) in the Python Console. Errors will show up there:Run Script in PyConsole (Menu)

You may also check out the Script Runner addon:
http://goodspiritgraphics.com/software/products/script-runner-addon/

It should be possible to run scripts like with Script Runner, but in the context of the Python Console. Some more info:

http://www.blender.org/documentation/blender_python_api_2_69_release/info_tips_and_tricks.html#executing-external-scripts


Remove selection overlays when Editing UVs? How can I view my meshes UV's in Edit Mode without a selection overlay? I want to be able to view my object with its texture map (and edit it) without having highlighted vertices/edges/faces obscuring my view.

You can get close (though you still need to keep Edit mode enabled):

In the 3D View's Properties region (N), go to the Display panel and enable the Only Render checkbox
In the Mesh Display panel, disable all of the overlays
Change to Edge Select mode in the 3D View (this at least hides the vertices, although the edges will still be highlighted).

And if you enable the UV Select Sync button in the UV editor (it's in the header), then the only edges you'll see in the 3D View are the ones that are selected in the UV editor.


Why doesn't "auto-fit" properly fit the compositor backdrop? Pressing the "fit" button in the sidebar of the compositor doesn't stretch the backdrop to the edges of the viewport. It's scaled smaller than it's supposed to be. How do I make the auto-fit function properly fit the compositor backdrop?

The Backdrop is merely a convenient display of what the Viewer node receives - to allow you to see the effect of changes to your compositor setup without having to switch away from the node view. The backdrop does not automatically resize as your viewport resizes - but does provide options to 'zoom' and offset the image - so you can position it so that the part of interest is not obscured by the nodes that you are working on.

Since the backdrop is intended as a convenient method of seeing a part of your render - so that you can tweak the nodes to see how it would look in the final render - it wouldn't make sense to distort those results (otherwise you wouldn't be seeing what would be output in your final render) - so there are no options to change the aspect ratio of the backdrop - so it cannot auto-fit to the shape of your viewport.

The 'Fit' button automatically sets the Zoom so as to position your render as large as possibly without any clipping - and this does mean that you will have blank 'bars' at the top and bottom, or at the side. Blender has no way of knowing which parts of the image you aren't currently interested in so you need to adjust the Zoom manually and optionally adjust the Offset to scale and position the image as desired.


When I move the my rig, it shows duplicate parts of the model I've started following this guide for modelling in blender, but have come across a problem when rigging. I've rigged everything and it works just fine to move some parts, but when I move my arm a duplicate arm shows up, unmoved! This also happens if I move the rest of my rig, it will show a duplicate hip, neck, and ankle joints!

My guess is that I somehow double modeled these parts maybe? I'd provide more pictures but since I'm new to Stackexchange I can't post more than 2 links.
I have no idea what I'm doing :O please help!

Nevermind I think I fixed it -- the joints that were not moving weren't bound to the armature, and the extra arm I just deleted by using "l" to select it and then deleting it.


Why is the Z very noisy around out of focus objects? I am doing a render of a tutorial I finished, and when I go compositing it I get a weird jitter on a defocused object. The tutorial had this too (at 1:04:00), but I wonder if it is possible to remove it. I tried adding a blur/defocus node but it ended messing up with the map value.

This is the jitter I'm talking about:

And this is my node setup:

It seems the Z always gets only one sample, so it's always noisy around defocused objects regardless of the number of scene samples. However using the mist pass (which was added since that tutorial was made) instead of the Z gives a better result:

To define the distance/thickness of the mist, enable the mist display in the camera settings so that you can see a visualization in the 3D view:

Then adjust the start and depth of the mist in world settings:


How do you specify the name of a new vertex group? Pretty simple question, it's pretty easy to create a new vertex group using bpy.ops.object.vertex_group_add(), but I can't find any way to specify the name of this new group without editing it in the Properties menu. Maybe I'm blind, but it just doesn't seem to be obvious to me.

You can use  obj.vertex_groups.new(name="mygroup") instead where you can specify the name while creating the group.

if you need to use bpy.ops.object.vertex_group_add() and want to specify the name after that you can also set it as follows :  obj.vertex_groups[-1].name="mygroup"


Spatial Audio Render How can I export B Format ambisonic audio in a render. Blender uses OpenAL, which does allow for First Order Ambisonic (4 mono channels, WXYZ) rendering. My goal is to create a stereoscopic, 360 degree video with spatial audio (audio field rotates with head).

Here are the documentation links regarding audio in Blender (many of them just say TODO):

https://docs.blender.org/manual/en/dev/render/audio/introduction.html

https://docs.blender.org/manual/en/dev/preferences/system.html#prefs-system-sound

https://docs.blender.org/manual/en/dev/data_system/scenes/properties.html#data-scenes-audio

I assume that the 4 Channels format found in the scene properties context has much to do with spatial audio. Can someone elaborate on these options?

Demo .blend file to play with (you'll need to supply your own audio):

Can use the mixdown operator to create an "audio render" of the scene.

Mixdown is next to the render animation button in the latest versions of Blender (There once was a mixdown button on the audio panel)

Otherwise go to the  python console and type in

bpy.ops.sound.mixdown('INVOKE_DEFAULT')

to call the operator as if a button was pressed.

Select a format that allows for the channels, wav is pretty foolproof.

I just added a simple mono wav file to your test file and selected basic old stereo.  Below is the result viewed in audacity.  Starts in left ear, moves to right as it rotates.

If I choose 4 channels I get a 4 channel wav file.

Which appears to be  Quadraphonic ears at (facing north) NE, SE, SW, and NW.  (Or speakers at Left Front, Right F, L Rear and RR) rather than W, X, Y, Z


Select object from within collection Can anyone tell me how I can choose an arbitrary object from within a collection? My script leaves me with nothing active (or selected) at one point, but I need something to be active.

I have the collection name from this:

Coll = bpy.data.collections.get('Structure')

So I can do something like this:

if Coll:
   for obj in Coll.objects:
       obj.select_set(True)

Which makes each object active one at a time, leaving me with the last one active at the end of the loop. But that seems pretty heavy handed. There must be a neater way.

How does this work?

from random import choice

# deselect all:
for obj in Coll.objects: obj.select_set(False)
# choose one and select it:
rnd_obj = choice(Coll.objects)
rnd_obj.select_set(True)


Material in material preview window becomes pale Good day. My "blush" in material preview window becomes pale, I need it with the same color as it's displayed in solid window with alpha blend. I'm embedding screenshot from shader editor with material settings. How can I fix it?
material preview window

solid window

shader editor

blend file https://drive.google.com/file/d/1mgDzZq4uhJx0obLe9iVUwuW2AJi4Z9Je/view?usp=sharing

i would propose you change your shader nodes like this:

Don't use the transparent BSDF but the color for the first shader.
I just hope you don't need this transparency...
result in material preview:


How to move a complex object to the origin without destroying it? I have a complex object far away from the origin of the scene itself.

If I mark all parts and use the Geometry to Origin function, the complex object gets crumbled, because all parts are set at the origin and the relations are destroyed.

Is there a way to move the object as a whole?

The object was an import from an STL file.

Go into edit mode, select all and press Shift-S and Cursor to selected.

Then go back to object mode, press Ctrl-Alt-Shift-C, Origin to cursor, and then press Alt-G (clear location).


Is this add-on "Extra Lights - Photometric Lighting For Blender" compatible with Blender 2.90.1 Does anyone know if this add-on "Extra Lights - Photometric Lighting For Blender" is compatible with Blender 2.90.1.  Here's the link to this add-on from blender market place:  https://blendermarket.com/products/extra-lights.  Thank you!

Yes, it is compatible with Blender 2.90.x. At the time of writing, this add-on will work in Blender 2.82 and later. The current version of the add-on can be found on GitHub, excluding the presets that are in the paid version.


Is my animation supposed to render frame by frame? i am just starting out of blender. i found a tutorial on how to make a text animation and it is rendering it frame by frame.. it is taking 10 minutes a frame and there are 140 frames. it is still rendering as i write this. i am using the cycles render engine..

An animation is perhaps best rendered frame by frame to seperate image files and then consolidated to a video file.

Heres why:  If your video fails to complete you lose it all. You still have the blender scene. In a long animation if it fails at say frame 64, you cn simply start it again and you will have all the individual frames to combine.

You can also farm the job out to a render farm , but there are issues there as well.

When I did the Dissolve tutorial (if thats what you did ) I think it took just over 1 minute per frame. Mine was 960 x 540

my PC - an intel celeron J1900 1.9 quad processor. Blender does not recognise a GPU (video card)


Box select doesn't select short edges When I do a box select on an object in edit mode where I only want to select the visible edges, after selecting and zooming in, I see it hasn't selected a bunch of small edges. How can this be? I cannot zoom into my model and then constantly check every short edge if it's selected or not, that would hinder my design process too much. This happens in both vertex select mode as well as in edge select mode.
When I zoom in, I can still select these edges no problem.
Using Blender 2.92.0
Is there a way or plugin to 'select visible edges' or 'select visible vertexes' or some other option? Right now I have to do a merge by distance, but it sometimes turns my artwork too low poly.
Example:

This is because when zoomed out, floating point errors cause incorrect detection of what edges are visually obstructed by other geometry when the edges are small compared to their size on screen.
You can get around this by going into a view mode where visually obstructed geometry may be selected.  Either x-ray or wireframe mode will do this.  It's unfortunately not a prefect solution but I find it works fine most of the time.


How do I apply all of my downloaded .tga textures to my model? I've encountered an issue with my model's texture's within blender.

I was able to apply one of the TGA files by heading over to UV/Image Editor and selecting a file called Reptile_B1_Diff.tga

The file itself displays the entire model's textures. However, there are still other textures files that need to be included such as the eye ball and some kind of blue/purple body to my model as well.

But whenever I open those files containing the necessary texture, the entire model changes to the selected texture and doesn't stay with the texture that it had before.

I am familiar with this scenario; it is common to have several texture maps assigned to a single model, especially in video games. You will need to know what geometry belongs to which texture, select that geometry, and then import and/or select the texture file in the UV Image Editor.

For example, the eye ball texture probably only belongs on the geometry that makes the eyes. So in edit mode, select only the eye geometry, and then in the UV editor you can select the appropriate texture. You can use things like the 'L' shortcut (select linked) to select connected geometry easily.


BlenRig Mouth Control Issue Not sure if anyone around he re knows but I have tried to use BlenRig to rig a character I made. Everything works except certain controls from the mouth_ctrl control bone.

I can move it side to side and the mouth moves correctly but when I move it up and down the mouth does not open like it is supposed to. The Vincent Character that is rigged using BlenRig works fine. Is there a control or setting I am missing?

This behavior might be caused by having the property JAW_ROTATION of the mouth_ctrl bone set to zero. Setting it to it to 60 should solve your problem.

You can find it in the CUSTOM PROPERTIES panel at the Blenrig 5 tab (like in the image above), the Properties panel at the Properties shelf or the Custom Properties panel at the Bone tab in the Properties window.


Imported animation from mixamo to unity causes left hand to act unusual Edit: I realised after I posted this question that it is on the blender stack exchange and this question is not actually blender related, however, I understand the files I am working with were designed and exported from blender so I feel that this is a relevant location for this question.
Edit: The eagle eyed viewers may realise that the icon shown in the first image indicates that I have added "Animation Rigging" inside of Unity. I added this to try and correct the issue, I can assure you that this is not the cause of the issue.
I am a software developer by trade and have little experience with the 3D modelling, rigging, texturing and animation pipeline.
I am just currently creating a hobby 3d shooter project and have imported a model/animation pack from mixamo in to unity.
Everything seems to have been imported correctly and all bones labelled correctly and in the correct position when in T-Pose in the game.
The problem:
When I start the game with the "Running While Aiming" animation everything works fine, apart from the left hand seems to be inverse in some way, see screenshots below:
This first image is the character in T-Pose showing the hands are correctly modeled.

This next image shows the character when the game is running and the "Running While Aiming" animation is active. As you can see, the left hand is in an unusual position with the "left hand pinky" finger being on the left of the left hand, when in fact the fingers shoulder be the other way round.

I have made no alterations to the model, the armature or animations. I imported everything to get going directly from mixamo as a package. I tried importing as a regular .fbx and as Unity .fbx and it has made no difference.
I would really appreciate some help on this if possible. I am a software developer by trade and am trying to create this hobby project to further my game programming skills.
Thanks in advance for any help or feedback provided.

once I found one solution, when exporting an animation at the beginning should be T pose, 0 frame T pose, 1 frame our animation, 2 or 3 frame our animation, in Unity we start cropping the animation with 2 or 3 frames


Tips for making Mesh Rigid-body collision shapes more stable Using the Mesh option in Properties > Physics > Rigid Body > Rigid Body collisions as the collision shape often makes the simulation unstable (objects jittering, falling through other objects, flying out of the scene, etc.)
This still can happen even after cranking up the Step Per Second value in Properties > Rigid Body World.

What are some methods for getting stable simulations while colliding objects with holes in them that other objects need to fall through? (for example a torus)

The tips below are great, but I noticed that problems still tend to occur with collisions between to objects with Mesh collision shapes.

Are there any other solutions for getting decent collisions with two mesh shapes?

Jittering objects are normally caused by the collision margin. See the documentation:

Collision Margin
The collision margin is used to improve performance and stability of rigid bodies. Depending on the shape, it behaves differently, some shapes embed it, while others have a visible gap around them:
The margin is embedded for these shapes:

Sphere
Box
Capsule
Cylinder
Convex Hull: Only allows for uniform scale when embedded.

The margin is not embedded for these shapes:

Cone
Active Triangle Mesh
Passive Triangle Mesh: Can be set to 0 most of the time.

And:

Simulation Stability
The simplest way of improving simulation stability is to increase the steps per second. However, care has to be taken since making too many steps can cause problems and make the simulation even less stable (if you need more than 1000 steps, you should look at other ways to improve stability).
Increasing the number of solver iterations helps making constraints stronger and also improves the object's stacking stability.
It's best to avoid small objects, as they're currently unstable. Ideally, objects should be at least 20 cm in diameter. If it's still necessary, setting the collision margin to 0, while generally not recommended, can help making small object behave more naturally.

Here's a quick example scene for you to inspect.


How to render only mist layer? I rendered in png sequence animation. How can I render only mist and than composite it together. Image. Thanks in advance.

You can't just render the mist pass on its own. Blender always renders the combined pass (even if you check it off on the Data passes for the view layer).
You will need to render again.
Enable mist on the data passes for the view layer

Then use the Mist ouptut of the render layer to save your image.

What you should do in the future:
Avoid PNG and save as OpenEXR multilayer.
Use a File Output node, set the output to the desired format and create all of the inputs you need:

That way you can save the image with other different passes. Think of EXR as an exact copy of the render layer.
Then import the file back in blender and the layers should be available for you in the compositor.


How do I get the console on windows? How do I get the console on windows? I opened the python console and it does nothing, and it isn't open on startup.


How do I make smoke fill a specific object How do I make it so that smoke only fits a specific object like a cube or sphere so the smoke makes the shape of the object.

Let's say I have a single object of a hat and what I want to do is make the smoke in the shape of the hat.

Help

I think this has been asked previously here:

Why isn't smoke flowing with the shape of the domain?

Basically - use a cube as usual as your smoke domain, and within that add your hollow hat-shaped object, make it a 'collision' object in the physics properties, and place your smoke emitters within that object.