Can I assign "U" for "undo"? I come from a very different CAD background with years of muscle memory with other tools that I would like to use with Blender.
Right now, I would like to associate the key U with "undo."  However, if I assign it in User Preferences, and re-assign "Make Single User" (in "NLA Editor" group) to a different combination, I still get the "Make Single User" menu when pressing U.

Is there a way to re-map "undo" to U?  I've successfully mapped ShiftZ and CtrlZ to zoom-out and zoom-in, respectively, for what it's worth.  (note: the CtrlZ to zoom-in, which I've grown accustomed to, is the particular qualifier why I'd like another key to "undo".)

I'm currently using Blender 2.75a under Arch Linux.

This is because the shortcut you re-assigned only applies to the Non-Linear Animation Editor.

To find all conflicting shortcuts, search based on key binding instead:

There are U shortcuts in the 3D view (both in object mode and edit mode) which call the call_menu() operator. This is different from the NLA editor, which just runs nla.make_single_user() directly when called since it has no options.

Disable or re-assign the conflicting shortcuts, then it works as expected.


How to find name of a nodes type to create with python I would like to create a ColorRamp node, but I don't know how it is called internally.
import bpy

selection = bpy.context.object
currentMaterial = selection.active_material
currentMaterial.use_nodes = True
nodes = currentMaterial.node_tree.nodes
colorRamp = nodes.new(type = 'ShaderNodeColorRamp')

The 'ShaderNodeColorRamp' does not work, the string is wrong, how do I find it's correct name out?

When creating the node via the search menu, the info area only say:
bpy.ops.node.add_search(node_item='69')

It's ShaderNodeValToRGB.
Turn on Python Tooltips under Edit > Preferences > Interface. Then go to the Shader Editor and hover over a node in the Add menu to see a tooltip with the name.


How can I print the string of a parameter from a property? Let's say I have this custom property fu3dm_model_gender: bpy.props.EnumProperty(name="Gender", description="Choose model's gender", items= [('OP1', "Male", ""), ('OP2', "Female", "")], default='OP1') and I want to print the string of name parameter. How can I do this?
UPDATE
Actually, my property is part of an operator. In the following example I'd like to get the string of name parameter and display it where the three X's (XXX) are:
class fu3dm_WM_OT_Model_Prefs_Operator(bpy.types.Operator):
    bl_idname = "wm.fu3dm_model_prefs"
    bl_label = "Model Preferences"
    bl_description = "..."

    fu3dm_model_gender : bpy.props.EnumProperty(name="Gender", description="Choose model's gender", items= [('OP1', "Male", ""), ('OP2', "Female", "")], default='OP1')

    def invoke(self, context, event):
        return context.window_manager.invoke_props_dialog(self)
        bpy.ops.wm.fu3dm_model_prefs('INVOKE_DEFAULT')

    def draw(self, context):

        layout = self.layout

    # BODY PREFS BOX - START
        box = layout.box()
        col = box.column()

        row = col.split()
        row.label(text=XXX)
        row.prop(self, "fu3dm_model_gender", text="")
    # BODY PREFS BOX - END

    def execute(self, context):
        pass
        return {"FINISHED"}

Yes. Once registered you can use bl_rna.properties to access the name, its type, the items, the description etc... I'd suggest use the python console to test:
>>> test_items = [
...     ("RED", "Red", "", 1),
...     ("GREEN", "Green", "", 2),
...     ("BLUE", "Blue", "", 3),
...     ("YELLOW", "Yellow", "", 4),
... ]

>>> bpy.types.Scene.my_enum = bpy.props.EnumProperty(name="Foo", items=test_items)
>>> bpy.types.Scene.bl_rna.properties['my_enum'].name
'Foo'
>>> bpy.types.Scene.bl_rna.properties['my_enum'].enum_items[0]
<bpy_struct, EnumPropertyItem("RED")>
>>> bpy.types.Scene.bl_rna.properties['my_enum'].enum_items[0].name
'Red'

In case of an operator property, I'd suggest read the values from the operators annotation dict:
class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"

    my_prop: bpy.props.StringProperty(name="foo")

    def execute(self, context):

        # via bl_rna
        print (self.properties.bl_rna.properties['my_prop'].name)

        # using annotations
        print (self.__annotations__.items())
        print (self.__annotations__['my_prop'][1]['name'])

        return {'FINISHED'}


How to modify accurate 3D models to protect technical know-how I have a 3D model from our engineering department with accurate measures of our product (format: VRML) that I want to give to a third party. The third party doesn't need an accurate model for what they are supposed to do with it. Now I want to modify the whole model with little effort to protect our technical know-how.

Does anybody know a solution in Blender to accomplish that?

I played a little bit with the decimate modifier and it looked promising.
The draw back I see with it, is the disproportionate effort I have to make since I don't know how to apply the modifier on ALL faces of ALL objects in the model.

Is it possible to get a short step-by-step tutorial to get all faces modified at once?

Another question that comes to my mind regarding the protection effect: If I modify the model and export it again to the VRML-format, then the modification I made in Blender is definite/destructive in opposite to the Blender-format itself where it stays non-destructive and I can adjust the modifier again. Am I right?

Setup your decimate modifier on one of the objects.

Then, in object mode, select all objects (A) or all needed object (Shift+RMB).

Make sure your decimated object is active (different color, usually brighter orange), if it's not, Shift+RMB on it.

Use Ctrl+L to open the link menu and select "modifiers"

All the selected objects will now have the exact same modifiers as the active object.

About export : modifiers are applied when exporting, so it will be destructive. There can be a checkbox (depending on file format) to apply modifiers or not.


Why is my smoke simulation not updating? I haven't seen this question during a search.

I have a simple campfire simulation with smoke. When I play the animation through the first time, smoke and fire both appear and evolve correctly. HOWEVER, the next time I play it through, the smoke/fire retains the shape and color it had on the final frame. It's as though once the simulation is stopped, the fire is frozen in that form for all the previous frames.
Is this a bug, or have I messed up somewhere?

My rig is:
AMD FX-8310 8 core processor
8G RAM
GeForce GTX 970 graphics card

It's being rendered in Cycles by CPU, but the problem shows up before rendering.
Unfortunately, I haven't been able to try this on another computer, or on another version of Blender.

Any ideas?

[EDITED TO ADD:]
Sorry, I have no idea how to attach a file to this post. HOWEVER, I have uploaded my .blend to google drive.

This appears to be the result of a couple things:

Negative start frame.
The simulator doesn't seem to like this, I suspect that it's a bug that negative start frames are even possible to set. (will report later)

The start of the scene animation is after the start of the simulation.
Blender only simulates when the animation is played from the starting frame of the simulation (not sure why it worked at all in your case actually).
Once the simulation is Baked or cached you can start at any point.

If you set the simulation start frame to 0 in Physics > Smoke Cache and then Bake, it works as expected.


Can you curve 1 edge without adding more edges to it? I've scoured the internet for how to make a simple, single curve from 1 edge, but apparently that is some monumental task in Blender lol

Here's a picture of what I'm working on:

I'm just trying to curve the selected edge to make it match the green curve to its left

I use Blender pretty much exclusively to rig clothes to 3D models, so about anything outside of that is foreign to me, but I'm trying to slowly venture out to learn more so I can use less other programs

Anyway, is there any way to curve this lone 2D edge without having to add more edges? Everything I saw online mentioned beveling, which as far as I could discern, involved me making and selecting more edges to curve, which won't work, need the number of faces to stay the same and for it all to stay in 2D in this step

Sorry if this is a dumb question, but I seriously cannot find anything that tells me a way to curve a 2D edge, which is driving me insane. I know there has to be some way to do it, even if it's not simple for whatever reason

Thanks

Just move some of your vertices/edges around like this, if possible for your design. (Select vertice and press G) Then you keep the same number of faces and your vertices end up on the curve.  And your faces are distributed more evenly making cloth simulation more realistic.


How to combine two curves for a camera animation I am working on a math-art animation in which a complicated object is changing and growing in the center of the scene. I want to animate the camera to follow a log spiral path that I've used a mirror modifier on to create a closed path that spirals out then back towards the object.

I'm using ADD:Curve:Curve Spirals:Logarithmic, then a mirror modifier. That works: I get what appears to be a single closed curve (it selects and shows in object and edit mode as one curve). But when I set up the camera to track on this curve the camera tracks correctly to the point where the original spiral connects to its mirror image, ignores the mirrored part, and jumps back in to the beginning of the original unmodified curve.I did the modifier part before any of the camera tracking part.

I'd like to know how to fix this manually for now, though ultimately I will add this piece to my python script that does most of the work in this project.

I've added some screen shots in both object mode and edit mode. In object mode the whole thing selects as one object but going into edit mode only the original spiral is highlighted and I can't seem to affect the mirrored half. Going into the object's curve tab Geometry panel I noticed that setting the bevel depth to non-zero bevels the whole thing. Thought this might be a clue to someone, though it just adds to my confusion.

You will need to apply the modifier

I'm not sure what the width will do, but I think you shouldn't have it unless you need it for some sort of visual for yourself.


Split Screen Resolution Problem (Game Engine) So when I run the game with the Embedded Player the split screen works but when I run it Standalone the size of the camera is changed.

Embedded:

Standalone:

I would like to make the standalone look like the Embedded.

Here is the code for the split screen if that is needed:

from bge import logic, render
camList = logic.getCurrentScene().cameras

cont = logic.getCurrentController()
own = cont.owner
cam1 = camList[own['cam1']]
cam2 = camList[own['cam2']]

width = render.getWindowWidth()
height = render.getWindowHeight()

cam1.setViewport(0, 0, int(width/2), height)
cam2.setViewport(int(width/2), 0, width, height)

cam1.useViewport = True
cam2.useViewport = True

Thanks!

I have that problem too. Try making the focal area larger, although it may be an issue with having two cameras.

Although, the snarky answer would be to restore down the game window.

Or you could do it like MarcClintDion commented. But really, make a note of the position of each camera, and slowly move them until you get the results you want.

Also, check if it's only going to fail with width. See if you can't stack the screens on top of each other, and see what effect that has on the width.


How to add shape keys to dimension of an object I am scaling one mesh plane using key frame but i am not able to see any effect in values of scaling of an object but yaa dimension of an object is changing.
So, i want to know that how to add shapekeys to affect the dimension of an object or how to scale object using shape key without affecting dimension of an object

Dimensions is just consequence of outside vertices rotated and scaled in object space. It could be modified only manually or by a script.


How to animate textures in blender internal and control them Is it possible to animate textures and then control them with a bone or empty? I want to animate eye textures blinking and looking in different directions etc. by of course drawing the frames. is there a way to control them like shape keys with bones and drivers?

You could put a Driver on the Mapping/Offset of an image texture that copies its value from a controlling empty or bone.

Here is a screenshot that shows such a rig.  Notice that the X offset is purple (meaning it is controlled by a driver) and you can see the driver in the curves window configured to copy the minimum value from the Empty object's X Location in World space.


Setting a bone in a particular angle I'm trying setting some bones in a particular way. One of my friends told me to set the bone on -180 0 0 PYR on Blender. However, to do that, I need to have the bones on a particular angle (0 0 0 I would say), but the armature comes with the bones already like this

What I want to achieve is making the bones have this particular angle

The issue here is I can't really ask him how to do it since he uses 3DSMax.
So, my question is, since that's already the neutral position, is there a way to rotate that bone in that angle? (-180 0 0 PYR)

Thank you in advance, I hope you can help me with this!

Key R, then the axis (X, Y, or Z), then the angle.


Automatic weights don't seem to work properly on the mirrored side of my model I seem to have the same issue as Automatic Weights Different on one side than the other
which doesn't seem to have a solution.

I've tried removing and reapplying the automatic weights on both sides and consistently the Right (mirrored) side doesn't add the weights properly while the Left (original) side does.

here's a gif showing the hind legs of the model on both sides

Is there a solution to this bug yet? (assuming that it is a bug of some sort)
I'm using 2.79, I think it has something to do with the mirroring process or the bone roll but I really can't say for sure.

If i have to manually assign weights to the meshes is there any way to make the them act the same on both sides?

If your mesh is strictly symmetrical, there's one easy solution to this. Just delete one half, apply the weight-painting, then add the mirror modifier (and apply it, if needed). Now both halves are identical, weight painting included.


Non-Metallic Surfaces are not receiving Roughness value Its my first time using the Eevee render engine. I want to learn how to render some game ready 3d models in Eevee.

My issue is that if the surface has 0% metallic value it will have 100% roughness in blender.

This is my intended result from Marmoset Toolbag 3:

But this is the result I am getting in the LookDev mode in Blender 2.8:

This is my shader setup. Its pretty basic using the Principled BSDF:

And finally this is my export setting in Substance Painter:

I greatly appreciate any reply.

Thank You.

Your specularity is set to zero which means it will be a completely diffuse material. Adjusting that value should give you the desired look, unless there is something wrong with the textures.

Specularity set to zero:

Specularity set to one:


Python and particle system I have been using this code to add a new particle system and create a name for it... I need help to choose the particle type "HAIR" and set other parameters.. This script does not work because the [part.001] keeps changing and going up. It will only work once when creating the first name.
I will need one particle system, so I can apply the code on other objects as well. It is a bit confusing.
The MBall is used as a particle to cover the entire surface of an object.

import bpy

obj = bpy.context.active_object
obj.modifiers.new("part", type='PARTICLE_SYSTEM')

bpy.data.particles["part"].type = 'HAIR'

bpy.data.particles["part"].count = 15000
bpy.data.particles["part"].use_advanced_hair = True
bpy.data.particles["part"].render_type = 'OBJECT'
bpy.data.particles["part"].instance_object = bpy.data.objects["Mball"]
bpy.data.particles["part"].particle_size = 0.15
bpy.data.particles["part"].emit_from = 'FACE'
bpy.data.particles["part"].distribution = 'RAND'
'

Python console code.

Add a particle system to the context object, Note the reference returned ps if the system names this system "part.001" it will be ps.name

>>> ob = C.object
>>> ps = ob.modifiers.new("part", 'PARTICLE_SYSTEM')
>>> ps.name
'part'

another

>>> ps = ob.modifiers.new("part", 'PARTICLE_SYSTEM')
>>> ps.name
'part.001'

The newly created particle system in the objects particle system collection

>>> psys = ob.particle_systems[ps.name]

psys.settings is a pointer to the particle settings stored in bpy.data.particles referred to by this particle system.  Notice it has the name "part.001" but we haven't used the name to find it at all, only a reference and pointer

>>> psys.settings
bpy.data.particles['part.001']

Use this pointer to set some properties (as in question code)

>>> psys.settings.count = 10000
>>> psys.settings.type = 'HAIR'

Can use this to set to a predefined set of settings, in this example a previously defined group of settings named "Wooble"

>>> psys.settings = D.particles['Wooble']
>>>


How to get custom menu items show up in the search bar? I have successfully created a sub menu which extends the Shift+A menu in the shader editor but I would like to have the options show up as results in the search bar. Is this even possible, and if so how can it be done?

import bpy
from bpy.types import Menu, Operator

def draw_menu(self, context):
    layout = self.layout
    layout.separator()
    layout.menu("sub_menu")

class SubMenu(bpy.types.Menu):
    bl_label = 'Math'
    bl_idname = 'sub_menu'

    def draw(self, context):
        layout = self.layout
        layout.operator("divide.node", text="Divide")
        layout.operator("multiply.node", text="Multiply")
        layout.operator("add.node", text="Add")
        layout.operator("subtract.node", text="Subtract")

class DivideNode(Operator):
    bl_idname = "divide.node"
    bl_label = "DivideNode"

    def execute(self, context):
        bpy.ops.node.add_node(type="ShaderNodeMath", use_transform=True)
        bpy.data.materials["Material"].node_tree.nodes["Math"].operation = 'DIVIDE'

        return {'FINISHED'}

class AddNode(Operator):
    bl_idname = "add.node"
    bl_label = "AddNode"

    def execute(self, context):
        bpy.ops.node.add_node(type="ShaderNodeMath", use_transform=True)
        bpy.data.materials["Material"].node_tree.nodes["Math"].operation = 'ADD'

        return {'FINISHED'}

class SubtractNode(Operator):
    bl_idname = "subtract.node"
    bl_label = "SubtractNode"

    def execute(self, context):
        bpy.ops.node.add_node(type="ShaderNodeMath", use_transform=True)
        bpy.data.materials["Material"].node_tree.nodes["Math"].operation = 'SUBTRACT'

        return {'FINISHED'}

class MultiplyNode(Operator):
    bl_idname = "multiply.node"
    bl_label = "MultiplyNode"

    def execute(self, context):
        bpy.ops.node.add_node(type="ShaderNodeMath", use_transform=True)
        bpy.data.materials["Material"].node_tree.nodes["Math"].operation = 'MULTIPLY'

        return {'FINISHED'}

def register():
    bpy.types.NODE_MT_add.append(draw_menu)
    bpy.utils.register_class(MultiplyNode)
    bpy.utils.register_class(SubMenu)
    bpy.utils.register_class(DivideNode)
    bpy.utils.register_class(SubtractNode)
    bpy.utils.register_class(AddNode)

def unregister():
    bpy.types.NODE_MT_add.remove(draw_menu)
    bpy.utils.unregister_class(MultiplyNode)
    bpy.utils.unregister_class(SubMenu)
    bpy.utils.unregister_class(DivideNode)
    bpy.utils.unregister_class(SubtractNode)
    bpy.utils.unregister_class(AddNode)

if __name__ == "__main__":
    register()

All the math node operations
Note: this doesn't answer how to put your operators into the search, rather is intended to offer another way to have same functionality in a far more easily extendable way

From one look at the question code instantly has me quoting

Foghorn Leghorn
No, no, no your're doing it all wrong

No menus one operator
Have taken code above and edited to have functionality as demonstrated, with no menus and one operator.
All the question operators are doing pretty much the same thing, the code varies little between them. Instead of an operator for each operation, one operator and an enum of possible operations.
The tricky bit.
When we add a math node, we add an instance of the type bpy.types.ShaderNodeMath.  All the possible operations are available from its definition of the "operation" property.
[Look for links, been well covered]
Our one operator is going to pinch these.
The menus can be ditched because blender can automatically make a menu from the options.  And boy there are a few.  The items list can be narrowed to a select few if desired
Categorize the other way
The naming convention of your operators is, going by "standards", a bit A about T. Using "node.add_math_subtract" will classify it with all the other bpy.ops.node prefixed operators.
Operators use context
For any code run in the shader editor the material we're "lookin' at" is context material. This is the material the bpy.ops.node.foo_bar will work on.  This will not always be bpy.data.materials["Material"]
Similarly only the first math node added via operator (bpy.ops.node.add_node(..)) will have the name "Math".  Hence on subsequent runnings of question code will add a new node but change the operation of the first one added, ie the one with name "Math".  Directly after running the operator the new node will be context.active_node .. another context member of the node editor.
Have instead added a math node to the node tree of the context material and set its operation and name accordingly.
import bpy
from bpy.types import Menu, Operator, ShaderNodeMath
from bpy.props import EnumProperty

class AddMathNode(Operator):
    ''' Add Math Node '''
    bl_idname = "node.add_math"
    bl_label = "Add Math Node"
    items = [
        (p.identifier, p.name, p.description)
        for p in ShaderNodeMath.bl_rna.properties["operation"].enum_items
            ]
    #print(items)
    operation : EnumProperty(
        items=items,
        name="Operation",
        default='ADD',
        )

    def execute(self, context):
        # the material in the node editor
        mat = context.material
        # add a new math node to its nodes
        n = mat.node_tree.nodes.new("ShaderNodeMath")
        # set some properties
        n.operation = self.operation
        n.name = self.operation.lower().title()
        # make active
        mat.node_tree.nodes.active = n
        return {'FINISHED'}
        #return bpy.ops.transform.translate('INVOKE_DEFAULT') # use translate

classes = (AddMathNode,)
def draw_menu(self, context):
    layout = self.layout
    layout.operator_menu_enum("node.add_math", "operation")
def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.NODE_MT_add.append(draw_menu)

def unregister():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.NODE_MT_add.remove(draw_menu)

if __name__ == "__main__":
    register()

Sorting them
There's lots of them. This change circa lines 9-12 sorts them by IDENTIFIER, eg ADD, SUBTRACT
    items = sorted(
        (p.identifier, p.name, p.description)
        for p in ShaderNodeMath.bl_rna.properties["operation"].enum_items
            )

Adding to the search menu.
Because this is now only a single operator removes the sense of searching for it.  Possibly the logical extension of this is to categorize the operation (as is done via the UI to select math node operation)
With developer extras set to show view source option can right click over the add nodes menu and view source, revealing how the search menu is constructed and laid out.
def draw(self, context):
    layout = self.layout

    layout.operator_context = 'INVOKE_DEFAULT'

    if nodeitems_utils.has_node_categories(context):
        props = layout.operator("node.add_search", text="Search...", icon='VIEWZOOM')
        props.use_transform = True

        layout.separator()

        # actual node submenus are defined by draw functions from node categories
        nodeitems_utils.draw_node_categories_menu(self, context)

Which reveals a helper module nodeitems_utils which we can pretty much pinch, to instead of using enum menu expansion can search and categorize.  Perhaps for another day.


Cycles not Showing Shadows Correctly - Works in Eevee This is a follow up to this post:
Cycles Textures not showing with shading - Works in Eevee
This is a similar problem. For some reason the translucent shader is not working properly in cycles:

Note, from left to right, it is Eevee, Cycles with the same light settings, and then Cycles with the point light turned down to 1W and no environment.
I have mixed translucency with the BSDF principled shader a more diffuse effect from the particles but it is acting a bit like a weak emitter. Also, you can see that the lens of the eye piece is emitting as well. There is no translucency set for that - it is just a simple image texture and principle BSDF shader. It ought to be completely in shadow.
For absolute sure, I am missing a simple setting somewhere. The Eevee version is what I ought to be seeing, but a little bit more realistically in cycles. What am I missing?
PS...I don't know if it is related, but Cycles is also ignoring the background when rendering. It is displaying a white background. (Blender 2.91.2)
Edit - I created a new blend file and appended the collection. I could not get the background to work properly in the original blend file. Once imported into the new blend file everything worked as expected. If any one knows if there might be seetting - I leave them to answer, otherwise the solution is to reconstruct the blend file.
Edit 2 - I have subsequently worked in the new file and attempted do use the same process. I added simple shaders to a low poly object, and in cycles it is not displaying the lighting correctly. The hat that I brought across IS displaying correctly. Again in Eevee, the new object (a boot) is displaying correctly. I cannot figure this out.

The answer to this is the "Ambient Occulsion" option in the world settings. If this is switched on, it is displaying the object "incorrectly" from the POV of what I would expect. Obviously, Eevee and Cycles handle AO differently. If anyone has anything else to add I would appreciate it (trying to learn here), but otherwise this was what was the cause of my issues.


Darker weight paint colors (Blender 2.8) Weight paint from Blender 2.79 (shown in Blender 2.8)

Weight paint created in Blender 2.8

Is this a problem? Also, if not, is there a way to change it back to the neon colored weight paint so that I'm able to see it better?

EDIT:

I tried tweaking up the custom colors, but they are still dark.

It's not so dark for me I don't know the reason why yours is. But it is adjustable you will find a colorramp for it in the preferences.

May be you messed up something here:


Can I get a new random number per ray in the node editor? In the node editor, I am looking for a way to get a random number (in [0,1)) per ray.  The object info node's random output just gives a random number per object, the number never changes.  I am looking for a way to get a new number every time the shader is sampled.

I am aware of this question, however that is not quite what I am looking for.

There's enough randomness in the Position from the Geometry node. It will almost never be exactly the same for two samples, but you have to apply a hash function to convert it to a random number in the [0,1) range.

The simplest solution would be to use a Voronoi or Noise Texture node with a very large Scale.

Another solution is to make your own hash function using math nodes, replicating for example this GLSL code.


Select Object randomly from group I'm currently creating an addon for Blender and got stuck at following task:
-I want to select one object with an unknown name from a group with known name
-I want this object to be an object instance that can be used in the following code

I tried many different things, but none of the worked.
One Idea was to list all objects of the group and than select one.

newest try:

bpy.ops.object.select_same_group(group=scene.object_group)

# select one object randomly from the actives
scene.object_group is a strong property with the group name

Get the group via bpy.data.groups, all objects of that group are accessible via a Group's objects property:

import bpy
import random

group_name = "Group"

group = bpy.data.groups.get(group_name)
assert group is not None

first_ob = group.objects[0]

random_ob = random.choice(group.objects)

If you wanna select another object from a random group the active object is in, use .users_group:

import bpy
from random import choice

scene = bpy.context.scene
ob = bpy.context.object

random_group = choice(ob.users_group)
obs = random_group.objects[:]
obs.remove(ob)

try:
    random_ob = choice(obs)
except IndexError:
    # no other object in chosen group
    pass

#bpy.ops.object.select_all(action='DESELECT')
for ob in scene.objects:
    ob.select = False
random_ob.select = True
bpy.context.scene.objects.active = random_ob


Increase depth percept of upside-down cup I'm trying to obtain a top view of a upside-down cup, with the camera displaced at an angle from the centre of the cup. However, the depth percept looks weak. I'm not able to tell that the base of the cup is nearer to me than the rim. Any help would be much appreciated. Thanks in advance.

Assuming your model geometry is good (I can't really tell from the screenshot), it becomes mainly a lighting, material and environment problem.

Lighting:
If you are going for a photo-realistic look, use Cycles for rendering. It will handle lights and shadows in a more intuitive way.

Material:
Is it suppose to be a styrofoam cup? A porcelain cup? Glass? Set up the material for the cup accordingly. Styrofoam would be almost all diffuse, with a Sub-Surface Scatter component. Porcelain would be diffused white, with an added layer of highly glossy top coat. Glass would be, well, the Glass material node.

Environment:
If the cup material is reflective at all, you will need to set up the environment so that there is something to reflect off. After all, a mirror ball in a perfectly grey world will only look grey.  Multiple Plane Emitters is a good starting point, they can mimic lights shining through a windows.


Why is the Viewport rendering completely different from the Camera rendering (Cycle, Transparent material with refraction) I have a simple scene with an "Image as plane" and a full transmission "hyperbolic lens" looking at it (scene built from the indications given at https://arachnoid.com/blender_graphics/index.html).
When I look at the viewport, I get a nice rendering (cycle progressive view mode).

When I ask for a camera rendering I get a strange sphere in the middle of the rendering, with a very strong magnification.

Any idea of what causes this discrepency? I would like to have a rendering w/o this artefact (if it's one).

in the inspector click icon of the filter or funnel

and enable the option that looks like a camera and the one that looks like a screen to the left of the camera

are there any objects with camera on but are hidden? or on in the camera but off with the screen?

alternatively is there a modifier that is different in the viewport vs render?


Glass cup + Water not rendering correctly, weird lines I'm just starting to learn Blender and am following Blender Guru's donut tutorial. I just "filled" the glass cup with water and everything looks correct as far as I know but when I render it, the water doesn't look right and there are some weird horizontal lines going on. As I said, I'm very new and don't really know what to look for.

Lines in transparent materials are a telltale sign of intersections with other objects. This was no exception.
To verify that there were intersections between the liquid and cup objects, I took these steps to generate a mesh that resembles the intersections:

Tab out of edit mode. This only works in object mode.
Select the liquid.
Hit the "Modifier Properties" tab of the properties window.
Create a new Boolean modifier (it's under the Generate group) with the following properties.

Operation: Difference
Object: Cup
Overlap Threshold: 0

Below is the screenshot of the results:

Yep, the cup and liquid definitely intersect. And notice how those lines match the lines in the render.
One way to fix the problem is by shrinking the liquid in the x and y axes. Here's how I did it:

Remove the Boolean modifier (that was just to see the intersections)
Select the liquid and only the liquid.
Tab into edit mode
Hit a to select all vertices
Hit s to scale them
Hit shift and z to lock the transformation in the Z axis.
Enter 0.99.
Tab out of edit mode.

Now the cup should look like this:

At first glance, it doesn't look like anything changed. But when you render the scene...

...no more lines!
One other thing to note is that the cup has some duplicate vertices. Make sure to use the "Merge by Distance" tool occasionally to clean those up.


How to avoid permutations of vector objects when dumping data? I'm trying to write a script which recursively dumps all data found in bpy.data.
The idea is when a .blend file is messed up I could compare it with an earlier version and could find the exact changes.

Running the script below the default scene already creates a 160 MB file this is caused by lines like:

bpy.data.brushes.clone_offset.xx.xx.x=0.0
bpy.data.brushes.clone_offset.xx.xxx.x=0.0
bpy.data.brushes.clone_offset.xx.xxxx.x=0.0
bpy.data.brushes.clone_offset.xx.xxxy.x=0.0

I don't understand where they do come from, how should I cope with vector objects?

The full script:

blender.exe --background -P dump.py

.

import bpy

map={}

def dump(obj, name="", level=0):
    if level > 5:
        return
    print("call %d obj=%s type=%s" % (level, str(obj), str(type(obj))))
    if str(type(obj)) in ("<class 'builtin_function_or_method'>",):#"<class 'Vector'>"):
        return
    if id(obj) in map:
        print("already dumped=%s" % obj )
        return
    map[id(obj)]=obj

    if str(type(obj)) == "<class 'bpy_prop_collection'>":
        print("isbpy_prop")
        for item in obj:
            dump( item, name , level+1)
            return

    if str(type(obj)) == "<class 'tuple'>":
        idx=0
        for item in obj:
            dump( item, name + "[" +str(idx) + "]", level+1)
            idx = idx+1
            return;
    for attr in dir(obj):
       if not hasattr(obj, attr ) or attr.startswith("__") or attr in ("bl_rna","base","rna_type"):
           continue
       val = getattr(obj, attr)
       if isinstance(val, (int, float, str, bool)):
          print("%s.%s=%s" % (name,attr,val))
       else:
          dump( val, name + "." + attr, level+1)

print(60*"-")
dump(bpy.data,"bpy.data")

The swizzle properties Vector.xyz return a new instance of Vector.

I.e. using a python property

class MyVectorClass(tuple):
    def get_xxx(self):
        return MyVectorClass((self[0],)*3)
    xxx = property(fget=get_xxx)

v = MyVectorClass((1.0, 2.0))
v.xxx.xxx.xxx
#equivalent to
v.get_xxx().get_xxx().get_xxx()

I would suggest Vector.to_tuple. That is everything you need.

BTW: To properly check for the type you should use isinstance

import mathutils

if isinstance(v, mathutils.Vector):
    t = v.to_tuple()


How to make backround image transparent? How can I make backround image transparent?

Now it is white and it is harr to understand where is my model and where image.

Select the image
Go to object data properties

Check Use Alpha and set the transparency


Ambient Occlusion Map dots I'm trying to create an AO map for my object. This is the result

As you can see the image is like created from little dots. The color isn't homogeneous. I don't know how can i describe better . . . it seems scratched.
It's my fault or this is the best result i can achieve? How can i improve my AO map?

These are the stats used

EDIT: Oops, I assumed you were using the Cycles renderer. For the Blender Internal renderer, it's a little different.
This is also sometimes called "grain" or "grainy" which might help your research.
Not to worry, you CAN get a better result. This is just because you've not rendered enough samples. The AO bake gets its quality settings from the "gather" section. Increase the number of samples and you will have a better result. Try adding 5 to the number of samples, and if it's still grainy, add 5 again. Keep adding 5 until you either get a good result, or the bake takes too long ;-)
There's even more information in the Manual:

Samples
The number of rays used to detect if an object is occluded. Higher numbers of samples give smoother and more accurate results, at the expense of slower render times. The default value of 5 is usually good for previews. The actual number of rays shot out is the square of this number (i.e. Samples at 5 means 25 rays). Rays are shot at the hemisphere according to a random pattern (determined by the sample methods described above); this causes differences in the occlusion pattern of neighboring pixels unless the number of shot rays is big enough to produce good statistical data.


Newly created objects linked by default When I create several objects, each time I try to work on a particular object, the rest of them are affected directly with any changes I make with the object I'm working on. Grouped by default. I clearly see that when I click to select on object, the rest of them are highlighted as well. How do I unlink this connection?

The picture is rather limited in regards of information (especially which mode it is in), so here a little info to ground my answer on:
If you have more then one object selected in object mode, the last selected one is brighter while all other selected ones are darker, if you then go in edit mode, they will all have the same color. Object mode can look like that picture in wire-frame mode.

Since they are in the same color, i would guess that you have those objects added while in edit mode and thus all are part of the same object, means if you select one of them in object mode all parts are selected. They are kinda joined, but only as in the meshes are under the same object. If you go in edit mode (i'd suggest vertex mode) and select all by pressing "a", you can then press "p" for the separate function and chose "By Loose Parts".
That way your meshes will be separated and each gets to be under its own object, means then you can edit them separately.


Blender 2.74 exporting custom normals without applying split normals modifier Blender finally added the possibility to use custom normals in version 2.74. YAY.
I've been playing with them to export and import a custom file format.

For example: I created the custom normals for a mesh, then call the calculate split normals and tessfaces methods

C.active_object.data.calc_normals_split()
C.active_object.data.update(calc_edges=True, calc_tessface=True)

and I can see the custom normals I expected

Vector(C.active_object.data.tessfaces[0].normal)
Vector(C.active_object.data.tessfaces[0].split_normals[0])

But if I try to use the Set Split Normals Modifier to create the normals, and even thou I can see the new normals working in the 3Dview, I can't find a ways to access those normals without appliying the modifier.

Can it be done?
How can access the new normals data without applying the modifier?

As @Jerryno said, from python you can only get modifiers’ results by applying them into a temp mesh (using Object.to_mesh()), there is no reason for 'EditNormals' modifier to behave differently.

You can also have a look at some official exporters supporting 'apply modifier' feature (like e.g. .obj exporter), that’s what they are doing.


What is the proper way to turn a mesh into solid white? I'm trying to use the grease pencil tool to try and mess with 2d animation in blender. I made a grid background but I'm running into issue with turning it pure white. Right now the background I made is grayish after applying color. Should I make a quick background image of pure white and import it? Whats the proper way of turning a mesh into a solid color?

pycoder's comment is correct. For future projects, you can directly adjust the background colour in the world tab.


Using pointiness and bevel at same time I'm making a chair and trying to use pointiness attribute to express the damage of paint at the edges. However the chair has bevel so when I put the bevel on, the corner gets rounder and the pointiness disappear. Is there anyway I can use pointiness as if there was no bevel?

Unfortunately no, I don't think there is a good way to do this.

As far as I know the Pointiness atribute relies on actual final geometry to work, thus can' be faked if the geometry is not really sharp.

For this specific shape You could try and fake it with a gradient texture centered of the object. It's an approximation, but with a little tweaking may achieve good results.

Just add a Gradient node connected to the Generated socket and adjust its positioning with a Vector node by [-0.05,-0.05,-0.05]. You can use a Color Ramp to adjust the progression.

You may also combine by color-mixing several different linear gradients to achieve an effect of a gradient starting from every edge.


Why am I getting frame rates less than 2 frames per second for my animations when I have an nVidia GeForce GTX card? I've set the nVidia card to be used by Blender in preferences and in the nVidia Control Panel. I've tried using Cycles and Evee.  The animation is of a single MB Lab character and no matter what I try, I still get less than 2 frames per second.  I'm not sure Blender is actually using the nVidia card.  Are there some other settings that need to be changed?  Thanks in advance to anyone who tries to answer my question.

2 frames a second on an animation render is pretty good, considering even most simpler animations + keyframes render at about 1.5-3 seconds a frame are the times most home PC GPU renders get on a render.
If you're sure these are bad frame times, you could try checking if Blender is actually using the GPU to render (if you're running cycles that is):

As others have said, it also depends on what GTX card - There's a big difference between a 1080 and a 1050.
Honestly though, like I said, 2 frames per second on any animation is not bad at all.


Adding Shaders To Mapped Texture So I used Agisoft Photoscan to render a model
it output a texture that is mapped to different sections of my model

My example:

I have a bunny's head and body

Texture1 is mapped to the bunnies eyes, head, and ears

I want it so that the bunny's eyes have a glossy shader applied to them WHILE maintaining the original mapped texture (kinda combining the mapped portion of the texture with a glossy shader) while avoiding making the rest of the head and ears glossy as well?

Put an alpha channel on the texture where you want it to be glossy, then use a color ramp node to mix between your original shader and a glossy shader.


How do I remove an exact rectangle from the rounded face of a hollow cylinder object? I have created some cylinders, removed the top and bottom faces from them, and used the solidify modifier on them.

I am trying to remove a section of the outer cylinder by using a cube of the exact size I want to remove. I thought that using the boolean difference modifier would work but it creates a sort of half union effect.

I can achieve a close result by subdividing the cylinder, moving the edges and then removing the faces, but it is not as precise as I was hoping to achieve.

I have provided some pictures of what I am trying to do and what is happening. Is there a better way for me to achieve this?

Thanks.

You can use the boolean / difference no problem.

It is such a simple shape that it will still be good topology after you apply the modifier. The reason that you get the hollow cube thingey, is that the two shape have exactly the same height. Weird stuff comes from 3D programs that will have to calculate difference between 2 items witch are the same location. If you scale the box on positive Z just a bit, it will work perfectly.

Usually I don't like boolean because it trashes the topology, but in this case it fits the part!


Blender 2.8 All menus disappeared Due to unknown reasons all my menus disappear, how can I bring them back?


New 2.9 Feature: Correct Face Attribute (checkbox) not available in Options Drop-down Now that I'm using Blender 2.9, I've been excited about using the Correct Face Attributes checkbox, which will allow me to resize my mesh and have the texture naturally extend (rather than be stretched).
However, when I click on the Options drop-down, I see only the normal Transform checkboxes (Origins, Locations, Parents). But no other options such as when I'm seeing in all these YT vids where people illustrate it.
Is there some new addon that I must activate to add this functionality?
Thanks.

No add-on required - It's under the "Active Tool and Workspace Settings" tab:

Bear in mind, you need to be in edit mode for these options to appear - they are not present from object mode (see below). However applying these settings to one object (in edit mode), applies it to all objects in the scene.


How to model and blend same like the image Hi I tried to model the below plug. But can't able to blend the back with the smaller front as the original. Is there a way?

I would do it with some bevels:

Create a cube. Mirror it on the X and Z axis.

Inset the front face with i and b for boundary. Pull it on the Y axis and extrude it.

Select the angle edges, and ctrlB to bevel.

Slide the new edges with GG so decrease the roundness on the back block angles.

Inset faces, add edge loops to sharp the angles...


Invisible object that hides other objects (as a mask) I'm trying to have an object set as invisible that hides other objects, but only when they are behind it.
I tried to use the object as a mask (by Compositing) but it works even if they are ahead it.

Thanks!

please note, I'm using the Blender Internal rendering engine

One way this can be done, is using the render layers mask layers. While this may not be as simple as Denis's answer, it's always good to know more than one way to do something, and it can be a bit more flexible because it works with both cycles and BI (and should work with basically any other rendering engine also).
Using Mask Layers
To create a mask layer, move your object(s) to their own layer. Generally you want this layer to be a bit out of the way. I've highlighted in a few common choices, but of coarse, you can use whatever layer you want to.

Then, to use that layer as a mask, simply highlight it in the mask layers layer group.

This effect is really useful for a lot of things, including VFX, and advanced compositing, but my favorite use, is to make something appear bigger on the inside:
How can I create a portal?


Object particles fly up, move in the wrong direction I'm new to Blender and I can't figure out why my particles move into the wrong direction. I made a plane with paper texture and cloth simulation, I use this object as the particle, my emitter is a cube. I want my particles to fly through the screen in front of a green plane. I changed my Z axis gravity to 0 and the Y axis gravity to 10.

However, when I start the animation the particles starts moving higher and higher, like the emitter is moving, while its clearly not.

I disabled every force other than gravity and wind, I'm using Blender Render, version 2.79b. What did I do wrong?

Well, I figured out what caused it. I don't know why (I'm a noob, sorry), but the gravity effector under cloth field weights on the object which I used as a particle caused this. I changed it to 0 and now it works just like I wanted.

Noice. Anyway, sorry for my stupid question.


What are the strange arrow things in the shader node tree? I'm relatively new to blender, I can't figure out what they are called or even what it is that they do. Please help. Thank you

Since Reroute nodes don't have any input or output sockets, they are essentially just one floating isolated socket it is impossible to clearly determine at first sight if one connection is coming in or out of said node.

For this reason, to make it clearer to the user, output connections show an arrow pointing in the information flow direction.


Blender file opening as new file My computer crashed while I was working just a little while ago and now my Blender file will not open properly. It hangs a while before opening as if it is a completely new .blend file (cube, camera, light). This is a 200mb file with a ton of stuff in it, is there any way to open it up?

Add'l info: I can't link or append the file either.


"TypeERROR" in animation nodes2.1 I tried to write a step_falloff node in animation nodes,but i failed,the consoul gave me an error:

and my code is:

import bpy
from ... base_types import AnimationNode
from . custom_falloff import CustomFalloff

class StepFalloffNode(bpy.types.Node, AnimationNode):
    bl_idname = "an_StepFalloffNode"
    bl_label = "Step Falloff"
def create(self):
    self.newInput("Integer", "Iterations", "iterations", value = 10)
    self.newInput("Float", "Factor", "factor", value = 1.0)
    self.newInput("Float", "Fallback", "fallback", hide = True).setRange(0, 1)
    self.newOutput("Falloff", "Falloff", "outFalloff")

def execute(self, iterations, factor, fallback):

    strengths = []

    for i in range(iterations):
        fl = factor*i
        strengths.append(fl)

    return stepFalloff(strengths,fallback)

class stepFalloff:
    def __new__(cls, strengths,fallback):
        return CustomFalloff(strengths,fallback)

and i put this code into falloff folder in animationnodes ,how to fix this? anyone has an idea ,thank you!

The CustomFalloff expects a FloatList object instead of a normal python list. So you should import the FloatList from data_structures:

from ... data_structures import FloatList

Then in the execute function do something like:

strengths = FloatList(iterations)
for i in range(iterations):
        strengths[i] = factor * i

return stepFalloff(strengths, fallback)


Rendering with studio light setup in World I have built a perfect setup on the Viewport with only studiolight, in my case sunset.exr, rotation 69 degrees and strength 0.4. When I switch the Viewport to Render mode (I work with 2.90 and Cycles) I see a perfect image. I have configured the World with the same sunset.exr image in order to get the same result on the rendered image, but I don’t know how to tweak the 69 degrees and therefore when I click F12 the resulting rendered image is different from the one on the Viewport. What should I do in order to get a rendered image result that is identical to the one on the viewport? BTW, clicking on View>Viewport Render Image does not work. Thank you for your kind advice.

You can use the Mapping node for that.

Add a Texture Coordinate node and a Mapping node before your HDRI
Rotate around Z axis
Done


Rigid Body Mesh Collisions: Objects falling through each other I have a scene  that I need to run simulations on, and quite a few of the collision shapes need to be set to mesh. This works fine for most objects but there are some that are acting weird, basically falling through each other.

Following the tips here and here, I have tried to solve this by:

Increasing the number of steps per second
Applying the object's scale
Tweaking the boundary margin
Subdividing the meshes
Flipping Normals

Further, the masses are similar and the dimensions are reasonable.

None of these tweaks have helped. Though the simulation runs fine if one of the objects collision bounds is set to convex hull. Is there something I can do to the meshes to make this work?

Example file:

As @m.ardito and @Rich Sedman pointed out, the solution is to remove doubles: Edit mode, select all, Remove Doubles.

The simulation now runs fine


Blender textures will not display in GE? How do I make my textures or colors display in blenders game engine? My textures in blender will not appear in bge when I run my game and it ends up looking like this:

I added some textures and colors to my objects in blender render but when I go into blenders game engine and run the game it looks black and white (image shows above shows no textures that I have added). I have multitexture enabled in my scene.

Any way of fixing this?

I figured the problem out.

Go to Materials for any of your objects in blender game engine
Select an image or any kind of texture you like
In game engine scroll down until you see bake drop down menu. Click the Bake drop down menu and leave everything as is unless you know what you are doing. I left my bake mode as full render and then I click bake button. You may or may not get an error but the error for some reason is wrong and your textures do end up getting baked so this must be a bake problem.
Then click Standalone player drop down menu and click star and boom you now see your textures!

Image of my game and texture below:

I haven't finished my texture for my game yet but this how I got my textures to appear finally. I wonder why when you press p you don't see any of your textures but as a standalone game you can, just odd :/.


Spacemouse NDOF, panning view2d other than front, right and top I’ve set up the 3Dconnexion spacemouse with NDOF configuration and in the 3D view it works to my liking.
Also when going in front, right, top orthographic view it works as expected and switches to pan and zoom.

What I am after now is being able to pan and zoom in the other 2D views like graph editor, dopesheet etc. I am unable to configure this.

I have tried to set de view2d pan action to NDOF, motion. But that resulted in a continuous pan when using the regular mouse.

Hopefully one of you can help me to configure this.

I don't think this is what you are after, but I bound "shift" to my left button on the Spacemouse.

This allows easy panning in 2d views by keeping my hand on the Spacemouse.

Good luck!


Why are the renderlayers rendering black? I understand there are a lot of questions similar to this but non of the solutions worked for me. I have a camera, I have lighting, rendering other things worked for me, I've restarted, etc.

Here's the rendered view for one of the renderlayers:

Here's the rendered view for the other one:

But when I render:

Black for both of the renders.

.blend:

This is because the Scene layers corresponding to your renderlayers are not enabled:

If you enable the right scene layers (or all of them), then it works as expected.

Note that by default the 3D view layers are linked to the scene layers. You may want to turn this off by toggling Lock Camera and Layers in 3D view > Header:

Also note that there is nothing on the Lines renderlayer; perhaps you meant to select this layer instead?


Blocky Textures around object, Blender render artifacts, possible causes? I'm getting weird render artifacts around the edge of a cylinder on the floor, blocky areas that look low-res:

(Edit) Image A: Blocky Textures behind the cylinder

Rendering from other angles shows the same render artifacts. Seemingly around the render box intersecting both the cylinder and floor.

I've tried changing anti-aliasing and other settings with no effect.

(Edit) Image B: Outliner, Viewport, and Render Settings

I'm at a loss. Any ideas?

Other Info:
   Blender v2.76.
   Blender Render.
   This floor texture is rather large, 12.3 MB file and 4288 x 2848.
   But artifacts happen with other (smaller) textures as well.

The problem was: assigning a UV Map to the Cylinder was somehow messing up the floor's texture or UV Map. I don't know why. But I was able to clear the artifacts from the render:

I fixed it by selecting the floor --> Edit Mode, and applying a UV Map to it, via the left panel (Shading / UVs tab) --> UVs section --> Unwrap. So both the Cylinder and floor have their own UV Maps.

I don't know why changing the cylinder created artifacts on the floor; they are two different objects, two different UV Maps, two different materials, two different textures. But this solution worked for me!


Joined objects remain separated in edit mode I apologize if this has been covered, but I have been unable to locate a solution.
I joined two basic objects together before applying array and curve modifiers, but they are still detached in edit mode. Is there a way to combine all vertices into one complete object? Any help is greatly appreciated.

if the vertices are close enough , you can Select all the vertices and click x to delete and do by distance , or else if you want to do manual work you can CTRL M to merge pairs of corresponding mesh vertex


Object not receiving message I have a game I am making, but I have run into a brick wall.  My player is not receiving any messages.  It uses Dynamic physics type and it is set to receive any message.  I want it to receive a message from a child circle below it.  They are both in the same scene.  I want the circle to tell the player that it is on the ground so the player can know when to jump.

The circle's script:

The player's script:

Possible cause: combination with keyboard sensor

Just as it is the configuration looks fine. But there is a danger.

You combine the message detection with keyboard detection. That means the actuator will only be activated when you hold the specified key  and receive a message at the same time.

It might be you want to activate the motion actuator when either the key is pressed or a message is received. In that case I suggest to replace the AND controller with an OR controller.

To analyze if the message can be received at all, you can disconnect the keyboard sensor (leaving the message sensor).

To analyze if the motion actuator has any effect on your object, you can disconnect the message sensor (leaving the keyboard sensor).

I hope it helps


Saving Z data linearly (accurate depth map) I want to create a depth map via the node editor by mapping the "Z" of my render to a "Map Value" node with Size 0.05. Basically this scales the depth down to 1/20th of it. When I save the resulting image as a .PNG or .EXR (using new GIMP version) the resulting grey values are not what I expected. They are not even linear. When I press the left mouse button in Blender on the render window, the values are very plausible (first RGB values where like R 0.1 G 0.1 B 0.1, the CM RGB values are off like in the saved pictures, e.g. R 0.3492, ...).
I made a test scene with planes at different z-values (see table) and looked at the curves:

I tried a gamma 2.2 correction and it seemed to linearize the output. But I cannot reconstruct my z values. With the plausible values from the render image "color picker" I can. How do I export THOSE values? I cannot post another link, but one person is saying that I should just output the Z directly without the scaling. Does the mapping node play a role?

There are a few things going on, here.

Firstly, the z-depth is exactly the distance of each pixel from the camera. You can demonstrate this by setting the clipping planes of your camera to specific values, and then using your mouse to inspect the RGB values in the render result view (not the saved image). The closest pixels will be the same value as your near clipping plane (assuming there's geometry that close), and the farthest pixels will be the same values as your far clipping plane (except for where the sky is visible, where the value will go to "a very large number"). I proved this to myself just a couple of days ago. I'll see if I can dig that project back up and upload a demonstration of some kind.

Secondly, those values don't fit in any typical RGB image. So anytime they need to be put into a file, they get mapped to 0-255. That means what might have been a 19-1200 floating-point range got squashed down to 0-255 non-floating point.

Lastly, when the image undergoes that transformation from floating point precision to 0-255, it ALSO gets mapped to a new color domain, which often includes a gamma adjustment and other strange transformations. It's usually quite effective for visual data, but plays havoc with numeric data.

The solution is an image format that is not limited to a 0-255 range for each RGB value. Enter OpenEXR and HDR. They can store the raw, floating-point values as they are in Blender, without compressing them... much. They're still limited to 32-bit floating point values, but that's plenty for just about anything.

So, if your data ever leaves Blender, it's been compressed somehow, unless you save it DIRECTLY to EXR or some other high-range format (without any intermediate nodes or processing). The best idea would be to use the buffer directly in Blender, rather than loading it from a file. If you do need to save it to a file, make sure that you're saving to some 32-bit format.

It may also be worth looking into the Mist Pass. It's similar... but different.


Joining (Ctrl + J) multiple paths bevelled by a shape ruins the whole shape So I was trying to make hair for my character and watched a tutorial that explained how you could create simple hair by bevelling a curve path by a curve shape. So I had done this and placed it on my character's head while editing some of the hair by shrinking or fattening the path's vertices, but then when I want to finally join all the hair together, the hair then changes shape, how can I make sure this does not happen and the hair maintains shape? The pictures below are before and after I join all the hairs that are being bevelled by shape than being adjusted through shrinking and fattening.

This issue is most likely caused by modifiers either having different settings or operating differently because of a sudden change in relativity to the origin point since upon joining the objects it uses the origin from the selected object, If this is the case I would suggest ensuring all the origins are in the same location before joining them. If not make sure there are no differences in modifier settings before merging them or simply apply the modifiers before merging the objects together as user DontWalk commented


Material Alpha Blend: Blending issue Hello Guys This is my first model and having hard time to follow tutorial that was made on older versions of the Blender.
Now I use 2.9 version which shows some weird behavior couldn't find the answer. please check the gif below to see it. when I switch to Alpha Hashed blending fixes but feathers appear pixelated or what. please any advice would be much appreciated.
One guy suggested to use same materials but in that case I will not have multi colored feathers.

The issue was fixed when I combined all feather meshes into one mesh.


Mantaflow use in blender .Blend file
I am a blender beginner and after watching some tutorials online I figured I'd give modeling and animation a try.
I am trying to make an oil hourglass animation that will move the liquid downwards.The hourglass is exactly the same as the one shown here, I have a physical reference of it.
The only issue is that my liquid doesn't seem to want to pass through 2 holes I made on the container mesh, I suspect it's because of the wrong facing normals right outside of it:

I managed to get the liquid to flow inside of the top sphere.

but It won't flow into the rest of the mesh.

Will I have to create a new mesh? Help is appreciated, thank you!

The first thing to note is you need to ensure that your domain resolution is set high enough so you have enough fluid detail to fit through any holes. Look at the small cube in the bottom corner of the domain - visible in your second image; that’s the size of one ‘cell’. Any hole smaller than the width of that will definitely obstruct your flow. Start by increasing the Resolution and/or increasing the size of your ‘holes’.
Also, make sure any obstacle meshes are Manifold (completely enclose a volume).


Bake particle system animation and delete few particles I want to delete few particles from particle system. After baking the animation still I cant select particle objects, it selects all of them.

The only way I know to edit already emitted particle objects would be to Make Duplicates Real Shift-Ctrl-A accessible in Object Menu after that you could select the mesh and invoke Separate by loose parts in Edit Mode P. This wouldn't help on animations.


Blank spaces in a font I don't think I had this problem show up on any other font, but recently I tried to use a font called Road_Rage.otf.

The problem is, when I import the font into Blender (Version 2.79), a lot of characters have blank spaces in them, when everywhere else, they show normally.

This is how it should look like:

And this is how it looks in Blender:

I don't know what causes it.

Anyone knows how to fix this ?

Booleans in 2D Curves don't support self intersecting curves. Text is just a fancy curve.

Two overlapping shapes of the same curve object, will show the difference boolean.

As you can see in the above gif, there appear to be errors at the intersections, which cause some problems with the tesselation.

In an open tasks Campbell Barton says:

  [...] its not a bug because the code is working as intended.
  Of course adding support for self intersecting curves could be a
  useful enhancement.

The font features some problematic self intersection bezier shapes, which cause everything to render incorrectly. Removing this shape form the T character
 result in a correct shape.

You can fix this manually by ⎇ AltC converting the Text to a curve. And then removing the problematic curves.

This can be also easily achieved, by separating various parts in edit mode.


Texture showing errors (edges of texture)? Here I have a simple white-to-transparent image in the UV editor.

I've selected a plane thats in correct proportion in size to the image, and I've unwrapped it.

At first, it looks just fine.

When you zoom in or focus at the very edge of the plane, you can see a little error: the texture and unwrap goes from white to transparent, but the object is showing a little white part at the edge of the object. It is small, but it is very noticeable in play-mode.

How can I fix this? How can I have the texture not show these errors?

Cause

I think the texture gets blurred either because it is scaled out or scaled in via automatic mipmapping texture.

Blur means the adjacent texels are considered when calculating the color.

It will include any texel outside the UV area. It even wraps around the around the texture's border (which is the cause of the effect you discover).

Solution

In both cases I suggest you shrink the UV-face that you get some border around the face (in UV-Editor).

Reference

See Avoid Seams in Textured Objects


Why are hair particle endpoints inhibited from getting close the the emitting object? So my issue is that I'm unable to get these hair particle endpoints to sit flush with the object they're emitting from.  There seems to be a forcefield limiting how close they can get to the surface.  How do I fix this :0?

Thanks for your time.

With your hair  selected go to particle edit mode and in your brush settings there is something called "Deflect Emitter".  Choose the distance you want or disable it for free editing, with no force field.


Subsurf adaptive on smoke? I have a big smoke simulation that's all baked and has been rendering for awhile. I just saw Blender Guru's video about adaptive subserf and was curious to know if it's possible to apply this to physics. It would save me a tremendous amount of time If I could render on my GPU!

Adaptive Subsurf is meant to change density of a mesh (as regular Subsurf). You can't control smoke by this as smoke is a Volume simulation.


How to add a normal map texture and a diffuse texture on a model in cycles? When I add a normal map texture in cycles I do this -

How to combine the normal map texture with a diffuse|color texture?
I don't have much knowledge about the nodes in cycles and I have no idea which node will combine them? Do I have to use the Color-Mix node? If so, how?

I think you want something like this:

Result:


Character texture is messed up As you can see above, that is my character, I modeled him, textured him, rigged him, used GLSL texturing, in the game engine, pressed "P," and he looked like this. I don't know what this is, is it transparent, I don't know? Please help!

I'm 99% certain that your normals are inverted. Try the following with each object:

-Select the object and tab into edit mode

-Select all of the vertices

-Use the Mesh menu to select Mesh->Normals->Recalculate Outside

Alternatively, you can select a face in edit mode and press ctrlf to "flip normals." This will just reverse whatever direction it already is, so it's not quite and handy, but it might be helpful if the first method doesn't work.

The actual problem is that polygons only have one side. If they're viewed from the "wrong" side, they are completely invisible. So, you have to make sure that the visible side is facing out, not in. The "normal" is the vector that points straight out from the surface of the visible side. So, recalculating the normals so they face outside will make it look right.

Good luck!


Error baking rigid bodies before rendering I'm using the following function to render my scene:

    def render_scene(self, file_name):
        bpy.data.scenes[0].render.filepath = os.path.join(self.output_path, file_name)
        bpy.ops.object.select_by_type(type='MESH')
        bpy.ops.rigidbody.bake_to_keyframes()
        bpy.ops.render.render(animation=True)

but I get the following error in bpy.ops.rigidbody.bake_to_keyframes:

  File "/snap/blender/33/2.80/scripts/modules/bpy/ops.py", line 201, in __call__
    ret = op_call(self.idname_py(), None, kw)
RuntimeError: Error: Traceback (most recent call last):
  File "/snap/blender/33/2.80/scripts/startup/bl_operators/rigidbody.py", line 174, in execute
    bpy.ops.anim.keyframe_insert(type='BUILTIN_KSI_LocRot', confirm_success=False)
  File "/snap/blender/33/2.80/scripts/modules/bpy/ops.py", line 201, in __call__
    ret = op_call(self.idname_py(), None, kw)
RuntimeError: Operator bpy.ops.anim.keyframe_insert.poll() failed, context is incorrect

How can I solve this problem?

Another way you could do it is:

def render_scene(self, file_name):
    bpy.data.scenes[0].render.filepath = os.path.join(self.output_path, file_name)
    bpy.ops.ptcache.bake_all()
    bpy.ops.render.render(animation=True)


Why is this texture repeating when its set to clip? I have positioned the black lines where i want them using object coordinates but for some reason it shows on the top of the hat as well even though the texture is set to clip which i thought prevented any repeating?

This is the way "object" coordinates work: it takes into account the bounding box of the object, puts the texture in a plane that goes through the origin and projects the same color value onto every face wich has the same XY (UV) coordinates, so the image can get repeated if two zones share the same XY coordinates (and maybe have different "height") in the bounding box world.

If you want  a single position you have to use UV coordinates instead.


Adding Initial Velocity in the Game Engine I am creating a gravity simulation where a an object is moving and is caught by another object and goes into orbit around it. The problem is that since I am an absolute noob in the game engine, I don't know how to give the object an initial velocity that allows it to go into orbit, rather than just colliding with the other object. Could someone help with that?

I have included a picture of the scene below. Sorry for being a noob. Thanks

You can add a force to the object by activating an motion actuator.

Ensure the actuator deactivates after applying the initial force (or velocity).

When you are working with dynamically added objects it is even simpler. You can set up an initial velocity of the added object.


How to direct a lamp into the camera In Blender Cycles, it is possible to automatically (Ctrl+Shift+Numpad 7) put the camera in such a position that the sun's rays shine straight at it. Is it also possible to automatically make the sun rotate so that its rays shine straight at the camera?

Perhaps you want a Track To constraint on the lamp targeting the object with To=-Z and Up=Y (although any up != Z would be good.)


Cycles Render Output Black So my problem is simple: My render output is black.
I have rendered correctly before but now fear that I have accidentally changed a setting. I can't seem to figure out what it is...

My file is on Google Drive; hope that's okay.

Thanks guys.

Go to the Properties panel > Render Layers tab > Layer dropdown and erase BoneMaterial as your Material:

From the Wiki (regarding Material Override):

Overrides all material settings to use the Material chosen here.
Examples of where this might be used:

To check lighting by using a plain diffuse material on all objects

Render a wireframe of the scene

Create a custom render pass such as an anti-aliased matte or global coordinates.

You had inadvertently changed every material in the scene to one that did not render correctly.
EDIT:
Newer versions of blender don't use layers, but "collections" so the override function is in the scene>View Layer section.

Additional info:
Where is the Layers panel in Blender 2.8?
2.8 - Is it possible to assign (override) a material to a whole collection?


Should I open two blenders to render with my GPU/CPU? I have a i7-2600 which is currently rendering a scene to .avi and is about 8 hours in and half way.  The CPU is at near 90% usage.

I also have a GTX 460 GPU (which I believe supports CUDA)

Is it a good idea to launch another instance of Blender and configure to render another scene with the GPU instead?  Will this have a negative impact on the other instance of Blender rendering?

This should work, but I don't know if you want to risk it because you are rendering directly to a video file.

If the animation render stops the avi file could be corrupted. Not to mention if your computer crashes it will be lost entirely.

This is why it is considered bad practice to render directly to a video file.

If you were rendering to an image sequence, then it wouldn't be a big deal even if your computer crashed completely because everything up to the previous frame would be on the hard drive.

To answer your question:
Performance wise, I tested this with a GTX 460 and a quad core intel xeon rendering two separate scenes in separate instances of blender.

There was a slight slowdown on the CPU scene when I started the GPU render, but it was barely noticeable. What made me certain that there was indeed a slowdown is that the time estimation for the CPU render jumped backwards about a second or two when the GPU render was started.


Freestyle Uniform Displacement I been looking online for this so idk if this is a duplicate or not, I never seen this asked before.

But for the curvy lines I went with the Sinus Displacement modifier in the geometry tab and its all spikey, I'm trying to smooth it but I have no clue what modifier to use for that.

But the bigger problem of the two is show below with the first picture zoomed out and the second picture Zoomed in.

I'm wanting the curves to be uniform but as you can see when zoomed out its less curvy and when zoomed in its more curvy. Is there any way how to set a uniform amount of curves to the sinus displacement?

Out:

In:

-please feel free to edit the question if you think it could be improved in someway, I don't really know how to make the question/post look better

Basically, you want to increase the Wavelength and Amplitude of the Sinus when the camera go closer to the object. You can do that with Drivers.

On the picture below, you can see the settings for the Wavelength driver :

a variable (named dist) return the distance between Cube and Camera
we invert it (1/dist), cause we want the value to decrease when the distance increase
we multiply it by a value (*200), which define the overall amplitude.

To find the right value, you can do trial and error, or calculate it. Here you can see dist is 10.439 ; say your desired Wavelength is 20 ; 1/10.439*x = 20 -> x = 20*10.439 = more or less 200.

The method is exactly the same for Amplitude. I used (1/dist)*30.


Object being squished when using object offset in array modifier I'm trying to make treads around a tire by applying an Array Modifier and using the Object Offset, but when I select object offset the tire tread it creates is squished in the X axis.

The offset object I am using is an empty plain axes, I've tried offsetting it to other objects and the same thing happened.

Figured it out, you just have to make sure that the scale of the object you're using as your object offset is the same as the object your applying the modifier to is the same.


exporting blender material to unity i created a lime with material in blender. it looks good enough for me in blender editor. i baked it and saved as a png texture file to use in unity. but i could not get same output in unity with this texture. i have attached related ss repectively.

thanks,

blender ss which i like the same in unity

baked ss

unity ss which i failed

Confirm that your baked texture is saved to your Assets folder and is visible in Unity as an Asset in the Asset Window. Confirm that the texture is actually being set as the Albedo/Diffuse on the Unity Material. IF not Drag the texture from your assets window onto that setting in the Inspector. May want to set your Material Color to white as well so that the texture is setting the color now.


Rigid and soft body collision - no interaction I'm trying to animate a basketball through the net, but I can't get collision to work.
I tried flipping normals for the net, but no luck.
These are my settings - I tried the net WITH and WITHOUT the rigid body physics - still nothing.
Any ideas what I might be missing?
EDIT:
I am able to make it interact with passive rigid body that I keyframe through the net, but ACTIVE does not. I can't figure it out.

It seems to be a bug of 2.8: https://developer.blender.org/T60079
You need to switch back to 2.79 if you want to feature
You can fake the gravity simulation and do as explained here:

the net should be cloth
the ball should be set as collision


Properties with min and max range looking at other property I created an Add-on with lots and lots of min and max values.
How can I made them looking at each other for the min and max value?
import bpy
from bpy.props import FloatProperty

class My_Props(bpy.types.PropertyGroup):

    My_Prop_range_min: FloatProperty(           name="My_Prop_range_min",
                                                default=1,
                                                min=0,
                                                max=100, # <--- This should look at "My_Prop_range_max"
                                                )

    My_Prop_range_max: FloatProperty(           name="My_Prop_range_max",
                                                default=4,
                                                min=0, # <--- This should look at "My_Prop_range_min"
                                                max=100,
                                                )

The minimum property should not be able to have a higher value than the maximum property is set, and the maximum property should not be able to have a lower value than the minimum property is set.
Is that possible? How can I do this?

The following example should point you in the right direction:
Any time the my_prop_range_min is changed in the UI the update function upd_min is called. The function then compares the UI setting to the current value of the my_prop_range_max. If the value of my_prop_range_min >= my_prop_range_max you just force it to be less than the value of my_prop_range_max. Similar when comparing max to min.
import bpy

def upd_min(self, context):
    if self.my_prop_range_min >= self.my_prop_range_max:
        self.my_prop_range_min = self.my_prop_range_max - 1

def upd_max(self, context):
    if self.my_prop_range_max <= self.my_prop_range_min:
        self.my_prop_range_max = self.my_prop_range_min + 1

class TEST_PG_props(bpy.types.PropertyGroup):
    my_prop_range_min: bpy.props.FloatProperty(
        name="My_Prop_range_min",
        default=1,
        min=0,
        max=99,
        update=upd_min,
        )

    my_prop_range_max: bpy.props.FloatProperty(
        name="My_Prop_range_max",
        default=4,
        min=1,
        max=100,
        update=upd_max,
        )

class TEST_PT_test_panel(bpy.types.Panel):
    bl_idname = "TEST_PT_test_panel"
    bl_label = "Test Panel"
    bl_space_type = "VIEW_3D"
    bl_region_type = "UI"
    bl_category = "Test Tab"

    def draw(self, context):
        my_props = context.scene.my_props
        layout = self.layout
        row = layout.row()
        row.prop(my_props, "my_prop_range_min", text="min")
        row.prop(my_props, "my_prop_range_max", text="max")

classes = [
    TEST_PG_props,
    TEST_PT_test_panel,
    ]

def register():
    for cls in classes:
        bpy.utils.register_class(cls)
    bpy.types.Scene.my_props = bpy.props.PointerProperty(
            type=TEST_PG_props)

def unregister():
    for cls in classes:
        bpy.utils.unregister_class(cls)
    del bpy.types.Scene.my_props

if __name__ == "__main__":
    register()


Reverse Edge Collapse I am trying to make edges such that parts of my mesh are smooth and rounded while others are sharper. Is there a way to perform an operation that does the opposite of an edge collapse? I guess the problem would be selecting which lines go to which vertex.

Edit:

Start like this:

and change it to this:

You can 'rip fill', with Alt+V. Once done you'll eventually need to remake quad : select the needed faces and Alt+J.


A Problem In Cell Fracture I Was Recently Trying Making A 3D Falling Text into The Ground And Breaking Up Into Pieces . But I Had A Problem In Cell Fracturing. When It Is Finished It Was Very Bad.

Before Cell Fracture :

After Cell Fracture:

I Added To My Mesh A Remesh Modifier Because I Think That It Will
Be Better But, Some Changes Only Happened And It Was not Perfect:

Actually This Problem Happens To Me Often In Blender And I Need Help Please. -Thanks-

Final:

Overview:

As for most of those issues the main problem lays in bad topology.

Example above is made from retopologized Text Object. It's not the best topology you can get but it should show you what you want to achieve finally. Quad based topology.

You can try to use Remesh Modifier. Check:

better Curve/Text to Mesh generation?
Change that convoluted font mesh

But those are examples for Text Object. As for more complicated meshes Remesh Modifier is not working very good.

  Take my advice and start making meshes with quad topology in mind. It
  will pay off quickly.

My example was made by deleting inner part of each letter and then filling them with new quads by hand. F2 and LoopTools addons can help you a bit.

I'm not making How to retopologize Text Object answer as this is not a part of this question.


check whether `trace()` collide a face at back or front side? How to check whether trace(ray,direction,...) collides the nearest face at front OR back side?
According to OSL: Anomalous normals returned by getmessage("trace"), these below codes won't work because it always return value as front-face (automatically flipped) from ray's perspective.
getmessage ("trace", "N", tN);
getmessage ("trace", "Ng", tNg);

The same link suggests that backfacing() is the solution.
However, it doesn't work.  I will show a test case below.
I have 2 cubes.

Here is my OSL shader of CubeA.
For every point of CubeA, shoot +z ray, and check whether the ray touches CubeB at CubeB's back-face (return green) or front-face (return red).
#include "stdosl.h"
shader tN_anomaly
[[ string help = "" ]]
(
    output vector hitBackfacing = vector(0,0,0)
){
    hitBackfacing=vector(0,0,0);
    if (trace(P,vector(0,0,1))){
        string tObj;
        getmessage ("trace", "geom:name",tObj);
        if(tObj=="CubeB"){
            hitBackfacing=vector(1,0,0);
            if(backfacing()){
                hitBackfacing=vector(0,1,0); //: never reach
            };

        }
    }

}

The below image is the result.  It suggests that backfacing() always return false.
It looks like to me that the backfacing() just cares about whether it is back-face from eye perspective, not from the most recent trace()'s perspective.
Left image = they are overlapping each other. (The correct result should be green.)
Right image = CubeB is above CubeA (not touching)

Here is my blend file.

Here is another blend file.  It is very similar, but I stretch Cube2 in x&y axis to cover the whole Cube1.  It also prints log z which > 1.

This is really @cppBeginner's answer to his own post.. (see commentary on OP).
The backfacing() function can be called on the implicit shading point in an OSL script, but is not available as an attribute returned in a message from a script-cast ray.
But many mesh and object attributes can be returned by OSL's trace(). See getmessage ("trace", ...) in the OSL specification.. this page of Blender source might help with types, etc.. (but that's only a grep, I don't strictly know how it ties in. Maybe someone can edit to flesh that out.)
These attributes include geom:trianglevertices,  which is an array of three 3D points: the coordinates in World space of the corners of the render-triangle containing the shading point. They appear to be in order, so the cross-product of two edges can be taken to find the direction of the triangle's normal, as defined by the mesh.
#include "stdosl.h"
shader Hit_Backfacing
(
    vector RayDir = vector(0.0),
    output int Hit = 0,
    output int Hit_Backfacing = 0
){
    if (trace(P,rayDir)){

        Hit = 1;
        vector triNormal = vector(0.0);
        point  triVerts[3];

        getmessage("trace","geom:trianglevertices",triVerts);
        triNormal = cross(triVerts[1]-triVerts[0],triVerts[2]-triVerts[0]);

        Hit_Backfacing = dot(triNormal,rayDir) > 0;
    }
}

In this example, the sign of dot-product of that normal and the cast ray direction tells us whether the triangle we hit faces us, or not...

The large plane carries the illustrated material.


Delete linked node from out-/inputs index Is it possible in python to look at the output or input of a node to which it is connected in order to delete it?
( Blender v2.92.0 )

The case in your picture can be done like
in_soc = your_principled_node.inputs['Base Color']  # example
if in_soc.links:
    from_node = in_soc.links[0].from_node
    your_material.node_tree.nodes.remove(from_node)


Animation Nodes - Can I make this a loop? I've been playing around with simple 3D fractals in Animation Nodes and have
worked out how to do this for example.

I could keep adding Replicate Matrices nodes to add more levels, but I've
been trying to do this as a loop, and not quite getting it to work.

In this example, if (M1, M2, M3, M4) is the list of matrices coming out of the Compose Matrix node,
I need the loop to add the following to the loop output at each iteration:

Iteration  Add to Matrix List                  Combined List Length
0          M1, M2, M3, M4                       n
1          M1*M1, M1*M2, .... M3*M4, M4*M4      n + n*n
2          M1*M1*M1, M1*M1*M2, ... M4*M4*M4     n + n*n + n*n*n
3                                               n + n*n + n*n*n + n*n*n*n

where in this example n=4
Any clues?

Animation Nodes loops have parameters that can be reassigned from within a loop. The option to do that is accessible in the Advanced Node Settings for the Loop Input node.

With reassignable parameters it's possible to keep both a queue of matrices that you want to transform, with each single transformation generating multiple additional queue entries that have to be queued, as well as a list of all matrices that have been calculated.

A first loop is created with three parameters:

A static list of matrices with the transformations, in this example a list of four matrices that scale an object by .5 and place it into the lower four corners of a cube
A queue with the matrices that have to be transformed in the current iteration. Once the iteration is finished, the queue will be overwritten with the transformed matrices as a new queue.
A list of all matrices. Once the transformed matrices are calculated for the current iteration we append them to the (initially empty) list of all matrices and reassign the parameter.

A second loop will do the transfromations for the queue items:

For each transformation matrix in the “transformations loop” we transform the whole list of queued matrices items by that transformation matrix. The Transform Matrix node is vectorized for multiple matrices but not for multiple transformations, so I chose Transformation to be the iterator and Queue Items to be a parameter and not the other way around, even though this approach would seem more intuitive to me. But in principle you can also add another loop and calculate, for each item in the queue, the list of transformed matrices.

Finally, the first loop is invoked like this:

As the first loop doesn't have a iterator in the Loop Input node, you can set the number of iterations in the Invoke Subprogram node.
The transformations are four matrices corresponding to the four bottom corners of a cube.
The queue is initialized with list containing a single standard matrix of location corresponding to the origin and a scale of one.
The initial list of all matrices is empty, so it doesn't need an input here. You could also feed in a list with the initial standard matrix above to also add the zeroth iteration to the output.

Blend file (using dev version of AN 2.1.2):

(It might be a good idea to disable automatic node execution when working with a larger number of iterations. Just as a word of caution.)


A question about the range of influence of the grease pencil sculpt mode I drew lines on the surface.
And I tried to modify the line on one side in Sculpt Mode.
But the lines on the opposite side move together.
Can you solve this problem?

While in sculpt mode, you can press C to circle select only the vertices you want to edit, confirm with right click, then enable this button to limit the sculpt to selected vertices.


Opening files from version 2.8 in 2.79 This is probably a silly question but I need some help. I opened a file that I've been working on for about a month in the new 2.8 version of Blender. However when I tried to reopen the file in version 2.79, the scene is completely empty. Here is where the problem lies for me, I accidentally saved over the original file save while in version 2.8 . Please help. Thanks!

You can copy the polygons from 2.8 to 2.79. You will lose your node setup but at least you will get back your scene. This happened to me just now - I couldn't find any answers anywhere, so i figured it out myself. I thought of this because you can do the same in Maya too, so I thought: "must work with blender too".


Water doesn't reflect the light So i tried make sunset animation, when i tried to make the water reflect the sun, it won't work. I don't know if it needs a GPU(because i use Integrated graphic, which is Intel HD Graphics 620) or not. Please help me. Also, i tried to search similar question, but i don't find it. Please help me.

Reflections do not work the same way in eevee as they do in cycles. To get proper reflections in eevee from an emissive object, you should use an irradiance volume and a reflection cubemap (Shift+A > Light Probe).

Make the probes big enough to encapsulate what you want to reflect, and then bake indirect lighting. See below:


Connecting separated edges I have a problem with the Blender sculpt mode. If I extrude one cube after the other, they're not connecting each other. That becomes a problem, if I want to start with the sculpt mode. I add an subdivison surface and their becoming to two kind of single parts(picture red), even if I join to the simple mode, I can't sculpt them because it's building a gap. Is there a way to connect these two parts (red) together?

Thanks for any help!

Try using remove doubles in the tool shelf (T) while having the part selected where the edges are separated. You can increase the merge distance beneath the tool shelf. If this doesn't give you what you want you can do it manually by zooming in to the edge that you want to correct in vertex select mode and selecting the two separated vertices. Then press Alt M and choose the option that's the best for you, probably at center.

Side note: Please make clearer question titles. 'Question about Sculpt Mode' is pretty general and nobody really knows what your question is about. Something like e. g. 'Connecting separated edges' would be better. Keep that in mind.


How to make a fluid simulation start from the middle of an animation and make the domain not visible until that point? Using blender 2.9, I am trying to simulate water filling a vessel. I watched to some videos, like this one: https://www.youtube.com/watch?v=1YKDUPEZc1g&t=321s. Note that in this video, the animation has 100 frames, the flow beginning in the very first frame and lasting up to frame #51.
However, I am trying an animation with 200 frames with the flow beginning only at frame #75 and lasting up to frame #125.
The problem is when I set Physics Properties - Cache - Frame start: 75 and Physics Properties - Cache - End: 125.
When I play the animation from frame #1, the vessel is blocked by the solid cube domain, which disappears when the flow starts.
My question is: How to make water start pouring in the middle of the animation?
Thank you!
** EDIT: .blend file added. **

in the domain, change the frames from 0 to 250 (or however your flow simulation lasts)
do not keyframe inflow type (delete those keyframes)
do keyframe use flow (74 - off, 75 - on)

4) free bake and bake all
-> works
visibility:
the domain itself normally is not visible, but the effector might be visible.
you can keyframe the visibility of objects here:


How can I thicken the walls of my model for a more sturdy 3D printing? Good afternoon,
I have been trying to print a 3D tile on my XYZ da Vinci 1.0 Pro 3-in-1, with Simplify 3D, but every time I try it seems that the lightness of the walls + the complexity of the inner layers affects the process and end up with this:

Instead of this

This is a photo of the 3D model

How can I make a blender model for this print?

The quick solution to make a Blender model of this is to export it as an stl then import it in Blender. Blender can read stl files. That's the quick, though often dirty, solution. It works most of the time, though you often have to check the model and redo some stuff.

I believe that the inner geometry of the piece is unnecessarily complex, thus why it generates so much problem. The gif, while fast, seems to show some problem arising when the model is sliced and it seems that there are missing layers and holes when I compare the end of the gif to the picture of the 3D model you provided.

That being said, my main concern, if I interpret your gif right, is the insane movements of the printer head! If I'm not mistaken, the thin red lines on the gif must represent the movements of the printhead, and they're all over the place! With such a geometric pattern inside, I would expect the printhead to follow the lines, but yours seems to jump all around.

That would also explain why your print fails: the printhead has to do too many retractions.

I would suggest to simply the inner geometry, and you can thicken the walls of an object using the 'Solidify' modifiers in Blender.

Although, I think it would be best to just rebuild it from scratch in Blender and make the walls thicker from the start.


Open GL Render. Anti-aliasing differences I have a simple scene setup:

Cube and a Sphere lighted decently.
Blender Internal renderer.
Shading - GLSL
Viewport Shading - Material.
I add the Scene in VSE and use Open GL Preview and Sequencer Preview Shading to Material.

Now when I hit the Open GL render button in the 3D View the scene renders with good anti-aliasing of the objects edges. But when I hit the Open GL render button in Video Sequencer Editor the objects are rendered with jagged edges.

Why is that difference and is there a way to Open GL render in VSE with proper anti-aliasing?

Thanks!

OpenGL rendering in the VSE ignores the AA settings because it just pipes the viewport output through while

  Render -> OpenGL Render Animation

is more like an own render engine utilizing OpenGL. The OpenGL AA setting is only used by that "engine".

You can still get AA by setting the resolution of your original scene way bigger (like 400%) than the VSE scene. Blender will first render the scene really big in OpenGL and then scale it down in the VSE, wich essentially results in antialiasing.


Can I add the output of the VSE as input to the node diagram? I know how to add the output of node composition to the VSE (add 'Scene'), but can I do the oposite?

I want to post-process my video sequence with a filter only available as a node (Stabilize) without pre-rendering it to a file first, because it would deminish quality and waste hard drive space and processing time. Can this be done? Or is the order (3D Scene -> Node composition -> VSE) fixed?

There is an addon to send VSE strips to the compositor:

http://blenderartists.org/forum/attachment.php?attachmentid=262986&d=1380892092

The selected video strips will show as image nodes on the compositor and then the resulting composition gets sent back as a new video strip to the VSE.

A video tutorial on how to use it is here:
https://www.youtube.com/watch?v=fiDlNm9iJs4