Mix colors from different objects at collision (Rigid Bodies and Particles) This will be a pretty complex question, many areas will be connected to it but it is for sure focused on one main problem. I'm not sure is it possible without heavy scripting and I didn't found anything on this topic elsewhere. So off we go.

Abstract:

I want to mix colors from different objects on collision.

Example. One cube is blue, second is yellow. Boom! Both are green.

I've made this little simulation:

Going deeper:

I think that the best option would be making material with RGB node, then, after taking color from another object mix them with MixRGB as below:

As you can see first problem is that Blender isn't mixing colors as it should, but let say it's close enough and leave it for now as is.

Second one is scenario with many objects. Using same approach will give us enormous amount of nodes - by adding another Mix and RGB. Replacing one color on the other hand doesn't give us proper mixing.

Solution for second problem could be making one RGB node from mixed values and waiting for another hit.

Wrap this up:

If there is any logic behind it, it could probably works like that:

Get RGB values of both objects.
Detect collision.
Mix values and replace existing RGB node value with new one.
Wait for another hit.

Advanced usage:

You may ask: "What you want to do with this dummy?" and my answer is:

Molecular Script from Pyroevil.

In this script there is collision system so (as far as I know about Python scripting like Jon Snow) it will be matter of adding color change thingy to this. Or I'm just delusional.

It will be great thing to mix particle collision systems colors. It could open new way to simulate fluids. If it's possible to transfer particle color values to IsoSurface in CubeSurfer or any other mesher possibilities will be endless (nooo, it's just for pouring blood to milk).

Blend file:

Here is my blend file if somebody wants to play with it (Molecular Script needed).

Using Animation Nodes
Updated for Animation Nodes 2.0!
Method with the Molecular Modifier and CubeSurfer below!!!
Another way to do this is using @Jacques Lucke's Animation Nodes addon. Here is the final result:

And here is a picture of the node setup:

This is done with a Rigid Body Simulation and Vertex Colors. After installing Animation Nodes (linked above), we can get to work.
1. Setting Up the Scene
First, we have to set up our Rigid Bodies. Add a ground plane, and under the Physics tab of the Properties Editor, click on Rigid Body and uncheck Active. For every object that we want to actively collide, click on Rigid Body, but leave Active checked.

In addition, under the Mesh tab of the Properties Editor, add a vertex color by clicking the + button under the Vertex Colors panel. Since we have to do this for every object, we can save ourselves some typing by leaving the default name, Col.

The last thing we have is give it a material. Call it whatever you want, and then create the following (Cycles) NodeTree:

This can be modified as needed, as long as the vertex color is still a part of the nodetree.
Repeat the above for all of the objects you want to mix color, giving the the same material, or just duplicate the one object. Finally, select all of the objects you want to mix colors and group them together (Ctrl + G). Don't forget to name it, either in the T panel or by hitting F6.

The scene is set up now. Let's dive into the Animation Nodes!
2. Creating the Nodetree
In the node window, click on the Animation Nodes. Add an Objects From Group node (to add a node, either press Shift + A and find the node, or press Ctrl + A to search for it). Select the Group.

The first thing we want to do is to assign random colors to each object on Frame 1. Let's create a subprogram to do that. Add a Loop Input node and name it SetRandCol. Press the + button next to New Iterator and type "Object List". Set up the following nodes:

To activate the loop, add an Invoke Subprogram node, select SetRandCol, and plug in the Object list. It should take effect immediately.

We don't want this to happen every frame, though. Just the first. Add these nodes to make it only work on Frame 1:

Cool. The next step is to calculate all of the different pairs of objects we will have to check collision against. We could do this with nodes, but it is faster to just use a short script. First, add a Get List Length node and plug in the Object list. Next, add a Script node and name it FindPairs. Press the + button to add a new script. Use the buttons to add 1 input (an integer) and 2 outputs (integer lists). Name them as follows:

In a Text Editor window, open the FindPairs script and paste the following:

obj1, obj2 = [],[]

for i in range(0,objcount):
    for j in range(i,objcount):
        if i != j:
            obj1.append(i)
            obj2.append(j)

To use the script, add an Invoke Subprogram node and select the "FindPairs" option. Plug the Get List Length node into the script node. obj1 and obj2 are all the pairs of objects (i.e. index 0 goes with index 0, etc).

The next thing to do is to create a loop that checks every pair for collision. We will do this with the Is Inside Volume node. Create a loop the same way we did the first time. Name it BVHCollide. Give it two "Integer List" iterators (named obj1 and obj2), an "Object List" parameter, and a "Float" parameter named Epsilon.

Add these nodes:

Next, we need to check for collision between the two objects. We'll use the Is Inside Volume node. After we check for collision, we'll combine our data to get a single boolean value for whether or not the two objects intersect:

The Epsilon parameter determines how far outside the loop the BVH node will look. Usually a super-low, non-zero value will work, like 0.0002. The last thing to do is to change the color of the objects. Add one more loop:

In the Advanced Node Settings dropdown of the N panel for the Expression nodes, be sure to uncheck "Correct Type":

Finally, invoke this last loop, and your simulation should work!

Blend File (requires Animation Nodes):

If you want to set the color manually, you can create this loop. Just provide it a list of colors with corresponding indices to the list of objects:

Incorporating the Molecular Modifier
Incorporating the Molecular Modifier has a similar workflow to the Rigid Body Method. Begin by setting up a Molecular simulation. Here is mine:

Here is the final result:

Node setup:

After setting up the molecular simulation, we can work on the coloring. To color the particles, we are exploiting a feature of the Molecular Modifier: since the entire simulation is baked with its own physics, the particles never rotate and therefore never use the Angular Velocity attribute. We will store our colors there. Set all of the particles to render as an Icosphere object and give the Icosphere this material:

Now lets get into Animation Nodes. Unfortunately, in Animation Nodes 2.0, the Particle datatype has been removed. The most efficient way to get around this is to create our own in Python. First, let's create an Extract Particles node. Add a Script node, and give it Particle System input and a Generic List output. Name the List ParticleList. Create a new script file and paste in this code:
ParticleList = []

for p in ParticleSystem.particles:
    ParticleList.append(p)

Next, we need a Filter Particles node. Add another Script node, and give it a Generic List input, four Boolean inputs, and a Generic List output. Name them as follows:

Here is the script:
Filtered = []

for p in Particles:
    if Unborn:
        if p.alive_state == 'UNBORN':
            Filtered.append(p)
    if Alive:
        if p.alive_state == 'ALIVE':
            Filtered.append(p)
    if Dying:
        if p.alive_state == 'DYING':
            Filtered.append(p)
    if Dead:
        if p.alive_state == 'DEAD':
            Filtered.append(p)

Last, we need a Particle Data node, to get information from the particles. Add another Script node, and give it a Generic List input, a Vector List output, a Float List output, and a Color List output. Name them as follows:

Here is the script:
Locations, Sizes, AngularVelocities = [],[],[]

for p in ParticleList:
    Locations.append(p.location)
    Sizes.append(p.size)
    AngularVelocities.append(p.angular_velocity)

For some reason, Animation Nodes doesn't like us using a Color List to store vector data, so disable Correct Output Types in the Advanced Node Settings panel of the N sidebar for the Script Node:

Now that we have that set up, we can get on to coloring the particles. For each of our particle emitters, add a Particle Systems from Object node. Add one of our ExtractParticles nodes for each Particle System:

We need a way to color the particles. Create a new Script subprogram named Color Particles. Give it two Color inputs and one Generic List input:

Code:
for p in particles:
    if color1 != color2:
        p.angular_velocity = [(color1[0]+color2[0])/2,(color1[1]+color2[1])/2,(color1[2]+color2[2])/2]

To set the initial colors for each particles system, use a FilterParticles node to get unborn particles, then the Color Particles node to set the color. Note that the two color inputs have to be different for the node to take effect:

Now, join all the particles together with a Combine List node and use a FilterParticles node to get a list of all Alive particles:

Next, we need to calculate all the different pairs of particles to check collision for. We can just use the same node we created above:

At this point, the numbers start to get really big, and unless you have an über-fast computer, you're going to start to lag. Even then, this NodeTree works better if it's only executed once a frame. If you haven't already, you should turn off Always in the Auto Execution panel of the T sidebar:

Ok. Next, let's check collision. Since everything is a perfect sphere, the math is pretty simple. The Loop node will need 2 Integer List iterators (obj1 and obj2), a Vector List parameter, a Float List parameter, a Float parameter, and a Boolean List output. Here is the NodeTree:

We can invoke it like so:

We now have a problem. We have an enormous amount of data. For my little 8000 particle simulation, there are over 2 million particle pairs that have to be checked for collision. If we also have to check if they need to have their colors modified, it would take forever. So, we should optimize the lists to only have pairs for which collision is true. Create a Script node with an  Integer List and a Boolean List input and an Integer List output:

Here is the script:
n = [i[a] for a in range(len(i)) if b[a]]

Use this Prune node on both of the obj lists:

Lastly, we need to change the color of all the colliding pairs. Since we already have a script to calculate and change the color of a pair of particles, we don't have to do much. Create this Loop:

Make sure to change the Slice Type from Index to Length. To finish, put in the Update Particles node:

Done!!!
Notes:
This will not run in real-time. For an 8000 particle simulation, it takes my (about average) computer 6-7 seconds to calculate each frame. Realize that the number of pairs increases quadratically, not linearly, so a 10000 particle simulation will take roughly four times as long as a 5000 particle simulation, depending on how many collisions there are.
Be sure to save before rendering. With both the Molecular script and Animation Nodes running, my computer froze once while rendering (I only have 8GB of RAM, though).

Blend File (requires Animation Nodes and Molecular):

Using CubeSurfer
We can even mesh our simulation and transfer the colors from the particles to the mesh. I'm using CubeSurfer to mesh my particles. It's pretty easy to pick up (controls are at the bottom of the Object panel) and there are tutorials online. Doing this will slow down the simulation a little more, but the NodeTree is pretty simple:

The two Reroutes are bringing in the list of active particles, and the locations of those particles, as labeled, from their respective nodes in the Main frame of the previous NodeTree. The object in the Object Input node is the Isosurface object created by CubeSurfer. You'll need to enable visibility for the Polygon Centers output of the Object Mesh Data node in the N panel. Here is the SetVertexCol script:
Object.data.vertex_colors.new() #Add a new vertex color, since it gets deleted at every frame change.
v_colors = Object.data.vertex_colors["Col"].data #Get the vertex color data
colors = [ParticleList[i].angular_velocity for i in Indices] #Get the colors for each face from the particles
i,j = 0,0
for f in Object.data.polygons:        #Iterate through each face
    for l in f.loop_indices:          #Iterate through each vertex
        v_colors[i].color = colors[j] #Paint vertex with color
        i += 1                        #Increment vertex
    j += 1                            #Increment face

The above code works because Vertex Color data is stored as a list of colors sorted by face, then vertex, which happens to be in the same order the Animation Nodes gets the faces.
Final Result:

It looks pretty awesome. Unfortunately, converting it to .gif form took down the quality. You can watch the full clip on YouTube here. I recommend watching in slow motion so you can see it frame by frame.

Blend File (Requires Animation Nodes, Molecular, and CubeSurfer):


How to handle creating a node group in a script? I am attempting to make a python script that creates a nodegroup based on some scene properties, however the group_make operator needs to be in a node editor context to run.

It seems awkward to try and make a node view temporarily while the script is running, as the plan is to create the nodegroup with a fake user and have the user add it from the add menu in the node editor.

How should I go about this?

Update: I have found that you can create node groups without a node editor with bpy.data.node_groups.new (thanks to ideasman42's comment here), however I still can't figure out how to add nodes to it.

How can I edit the nodes inside nodegroup without a node editor?

I can't find node_tree for my node group. Here is my problem:

eq_node = bpy.data.node_groups.new("Equal", "ShaderNodeTree")

tree = eq_node.node_tree #This gives "no such attribute 'node_tree'". How can I acces the node tree of the node group?
nodes = tree.nodes
links = tree.links

#Create nodes in node group here with nodes.new

Thanks to iKlsR's response the complete answer here becomes mostly the same -

import bpy

# create a group
test_group = bpy.data.node_groups.new('testGroup', 'ShaderNodeTree')

# create group inputs
group_inputs = test_group.nodes.new('NodeGroupInput')
group_inputs.location = (-350,0)
test_group.inputs.new('NodeSocketFloat','in_to_greater')
test_group.inputs.new('NodeSocketFloat','in_to_less')

# create group outputs
group_outputs = test_group.nodes.new('NodeGroupOutput')
group_outputs.location = (300,0)
test_group.outputs.new('NodeSocketFloat','out_result')

# create three math nodes in a group
node_add = test_group.nodes.new('ShaderNodeMath')
node_add.operation = 'ADD'
node_add.location = (100,0)

node_greater = test_group.nodes.new('ShaderNodeMath')
node_greater.operation = 'GREATER_THAN'
node_greater.label = 'greater'
node_greater.location = (-100,100)

node_less = test_group.nodes.new('ShaderNodeMath')
node_less.operation = 'LESS_THAN'
node_less.label = 'less'
node_less.location = (-100,-100)

# link nodes together
test_group.links.new(node_add.inputs[0], node_greater.outputs[0])
test_group.links.new(node_add.inputs[1], node_less.outputs[0])

# link inputs
test_group.links.new(group_inputs.outputs['in_to_greater'], node_greater.inputs[0])
test_group.links.new(group_inputs.outputs['in_to_less'], node_less.inputs[0])

#link output
test_group.links.new(node_add.outputs[0], group_outputs.inputs['out_result'])

To perform the same in 2.66 or older use -

import bpy

# create a group
test_group = bpy.data.node_groups.new('testGroup', 'SHADER')

# create group inputs and outputs
test_group.inputs.new('in_to_greater','VALUE')
test_group.outputs.new('out_result','VALUE')
# add a node
node_add = test_group.nodes.new('MATH')
# link them
test_group.links.new(test_group.inputs[0], node_add.inputs[0])
test_group.links.new(node_add.outputs[0], test_group.outputs[0])


Prevent having to rotate faces every time I unwrap an object I tend to re-unwrap objects a lot during my workflow / experimentation.

Whenever I add a new object with the same texture, I like to make the texture match the scale of it's siblings, so I unwrap all objects with the same material then scale the textures accordingly.

For example - Making a wood grain follow the length of an object instead of its height.

Unfortunately, whenever I do this, I have to re-rotate the faces of previous siblings.

Is there a way to make the faces stay rotated, so when I unwrap it again the faces stay in the desired orientation?

It looks like "Pin" is what I was looking for.

In the UV Editor highlight vertices, edges, or faces you want to pin then:

Right Click -> Pin

This keeps the UV's wherever you left them during the last unwrap.


How do I hollow a 3D model in Blender? I am new to Blender and barely know it's features. I am working on a game and I have to make flying airplanes for it.  I want to hollow the fuselage of the plane so that I can make the interior of the plane. I am using YouTube tutorials for the time being, but I haven't found one where the fuselage gets hollowed. I will also need to make plane windows, I think it has to do with the main title of the post. Can you guys help me? Thank you in advance!

I also think you need to use solidify modifier. It add thickness to you polygones. Simply, make windows holes into your fuselage and then use solidify modifier. And you will have hollow fuselage with windows.


Blender Imported file.OBJ I not showing up I got Blender a few hours ago, and I have been trying to import an .OBJ file, but it's not appearing.

I have tried to rescale, fix clipping, outline is on, and it's not outside of the plate either.

If you expand the tree list in the upper right for that object, you can see what materials are attached to it and possibly reattach them without having to re-extract and re-import.

Depending on the size of your object, it may also be hidden by the clipping planes.  When I can't find something, I go to the menu on the right of the 3D window and change the clip to a really high number (usually 1,000,000 or so).  Since the object shows up in the list on the right, another thing you can do is select it in that list, move the mouse back to the 3D window, and hit the period key on the number pad to zoom to that object.


Blender API: Return value of bpy.data.objects(ID).show_bounds and .bound_box I am getting started with the Blender Python API and there is something I do not understand. Lets say I have an object called "myObject" and I wanted to get its dimensions, then I type

bpy.data.objects["myObject"].dimensions

in the python console and get the result. The API http://www.blender.org/documentation/blender_python_api_2_71_release/bpy.types.Object.html#bpy.types.Object states, that an object also has a bound_box. But if I type

bpy.data.objects["myObject"].bound_box

simply the command I typed is returned! Why is that and how could I have known from the doc of the API? Also, when I type

bpy.data.objects["myObject"].show_bounds

it only returns "false". Why? If I go to the object properties panel and click "Bound" the bounding box is drawn. Why does that work and doing the same (?) via the console does not?

Thank you!

Object.bound_box does not contain mathutils-types like Matrix or Vector, it's a plain property array of float[3] which has no representation format like other types do.

You need to iterate over all elements and print them, e.g.:

for b in bpy.context.object.bound_box:
    print(b[:])

# (-1.0, -1.0, -1.0)
# (-1.0, -1.0, 1.0)
# (-1.0, 1.0, 1.0)
# (-1.0, 1.0, -1.0)
# (1.0, -1.0, -1.0)
# (1.0, -1.0, 1.0)
# (1.0, 1.0, 1.0)
# (1.0, 1.0, -1.0)

Or make a list of Vector objects:

[Vector(b) for b in bpy.context.object.bound_box]


scaling problem with rigify when using multiple objects I am having an issue where when i move any of the rigify armature bones, the objects are being scaled up, as seen here:

I am using individual objects for each bone that is parented to the armature by bone as to not bend them.
I would like it if the objects didn't scale up every time i move the bone out of range and for the armature to be limited to the current scale of the object, as you would have if using one object with the rig.
If anyone has a solution, it would very much help when it comes to posing and animating!

Select your rig, go to pose mode and select the IK control.
In N-panel > Item > Rig Main properties set IK stretch to 0.


How do I get this wing to uv unwrap correctly Im completely new to blender.  I'm trying to recreate this drawing of a butterfly my daughter did so I can bring it into Unity and surprise her with it.  I'm able to unwrap the bottom wing by adding a seam around it, and then down the side.  But when I try with the top wing things go crazy.  I'm not sure what I'm doing wrong and any help would be appreciated :)

Thanks!

Maybe join the eyes, in my opinion it's simpler to have only one object.

Your problem is that you have overlapping vertices, it messes up your unwrap, you need to select all in Edit mode and AltM > Merge By Distance.

Make sure that your seams are well placed, i.e. all along the shapes as if it was a costume sewed (see screenshot). Then you can unwrap.

You can increase or decrease the size of some islands (UV map elements) in the UV Editor.

At the end you'll probably need to apply the Mirror modifier for Unity, by default I guess the mirrored left part will overlap the right part in the UV Editor.


Is there a better way to extend a Bezier Curve? It seems very tedious and therefore slow to extend Bezier curves while creating them in Blender. The docs say to select two control points and W > Subdivide. This makes extending the curve unreasonably difficult, since after adding an additional control point (which is where you need the new point to be) you must then manually move both the end point and the new point into their desired positions, adjusting their handles, etc.

When extending the curve, even moving the current end point to where you want the next point to be (prior to subdividing) is odd and difficult, requiring many adjustments after subdividing to get the new point. Is there a better way?

Create a bezeir curve.

In edit mode select a control point at the start or end of the curve.

You can press:

E to extrude (and move) a new connected point
Ctrl Left Mouse Click to create a new connected point.
To make new control points that are unconnected to the existing curve deselect any previously selected control points and press Ctrl Left Mouse Click
V to set handle type (vector straight, aligned, free, etc...)
New points are the same type of active (last selected) control point.
AltC to close a curve

For more info see the Manual


Macbook OS v10.11.6 Can't Open Blender I am getting the following error message...

"The application “Blender” can’t be opened."

No follow up information, no "...because we can't identify the developer, etc.," just that.

Please help!

go to security and privacy and click on general then click on open anyway


N64 style vertex shading/lighting for low poly models? I can't find info on how to achieve this. I'd like to make n64 style graphics and imitating the way models and environments are "lit" is the part I'm very lost on. I've heard it's a kind of vertex shading but I'm not sure how to do this, in blender specifically and accurately to how it looks on n64.
One example of what I mean is seen very well in pokemon stadium:

And a more dramatic(and nice looking) example is bongo bongo from Ocarina of Time:

This is not how the actual model looks obviously, as there is lighting effects added for the game. How can this style of shading and lighting be imitated in blender?
Edit: In addition to manually painting vertexes for certain lighting effects, I also found some sources that say that the N64 used gouraud shading, but I can't for the life of me find any information on how to render something in blender with such shading. Any help?

I'll give this a shot since no else has answered yet.
The N64 had a semi-programmable color combiner, but the most likely mode is probably "modulate" where the texture color is multiplied by the shade color to produce the output color.
The shade color can be either be static vertex colors, or it can be calculated dynamically from the lighting.
Vertex Colors
For the vertex colors, you can hand-paint the shading into the vertex colors, or have Blender bake to vertex colors. Use a node setup like this:

This should be pretty accurate to the N64.
Lights
In this mode, the shade color is a Gouraud Phong-type shading computed from the normal and the lights. The N64 had one ambient light and up to eight directional (diffuse) lights. You can emulate the ambient light in Blender by setting the Background color for the World. For the directional lights, use Suns.
For the nodes, I don't know if you can do Gouraud shading (shading computed per-vertex, then interpolated) with Blender. But you can do it per-pixel with something like this

The diffuse node computes lighting. The node labeled "Clamp" keeps the shade color in the 0-1 range.
Also set Shadow mode in the material settings to None.
However, this is less accurate to the N64 than using vertex colors since it isn't Gouraud shaded.


Why hair particles inside I have a mesh and added hair particles to it with some settings. The hair are growing inside the mesh. I have weight paint the mesh so that it grow outside the mesh only. Still the hairs are inside and outside. I added the vertex group below in density. May i know the reason why the hairs are inside.

Problems come from two issues: rotation not applied and mesh with Ngons.
To solve some of them you can:

free particle edit of your "small hair2"
select the mesh and apply rotation and scale (Ctrl+A
)
recomb your hairs

To solve all issues, do a quick retopology to have a "quads only" and "edge loops only" mesh, and exclude from the vertex group all vertices that belong to the internal, borders also (think in terms of which faces you want to emit hair).

Another workaround could be make a copy of the external part of the mesh, delete the Ngons and extrude the last circle loop to reach the position of the previous borders, assign the particle systems to the new mesh and uncheck the "emitter" option in the particle render tab, so that the new mesh will not be rendered.


Cycles sky : Sun disc appears only in reflections Here is a render example of my problem.
A plane with a glossy material will reflect the sun disc, but the sun itself doesn't appears in the sky.

Any idea ?
(i've used the "Sun Position" addon to help for positioning the sun, but even if i don't use it, the sun didn't shows itself)

I'm currently using Blender 2.7 on PC, i've try on a Mac, the problem is the same.

Regards,
Arno

Lamps in Blender Render
In Blender Render you can turn Halo on, and the light will be visible to the camera.

Lamps in Cycles Render
You can't see lamps if you are using Cycles Render. That's one of their defining qualities. Here is a quote from the Blender wiki:

"Next to lighting from the background and any object with an emission shader, lamps are another way to add light into the scene. The difference is that they are not directly visible in the rendered image, and can be more easily managed as objects of their own type."
(Source: http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Lamps)

So, if you need a visible light source in Cycles, use either mesh lights (i.e. meshes with an emissive material) or for example an HDRI with a studio lighting setup.

New Experimental Cycles Volume Scatter Feature
The only other way you can see the light source in Cycles is with the new Volume Scatter:  http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Materials/Volume

Just to give credit where credit is due, all the information I've listed here I have gotten from the Blender Developers and members of BlenderArtists.org, which also is a great knowledge base for everything Blender-related. Here's the question I asked about lamps:
http://blenderartists.org/forum/showthread.php?331453-How-can-I-see-a-lamp-in-a-scene&p=2607054#post2607054


why does my rigged mesh deform I have rigged all my mesh and woks fine except for the eyelids. When I move the respective eyelid rig-bone simulating eyes closing, the eyelids get an odd deformation as in the picture below. I re-edited some of the polygons there as I though it could be a defect on the modelling but It stills having the same problem.
is there a solution for this?
thanks in advance

I'm not an expert on this, but i think bones aren't really used on delecate things like facial expressions. I think something called face shape keys are used instead.


How to move along depth axis on a mac? If I want to move the user view in Mac, I can do it by pressing Alt + Shift + LeftMouseButton. Note that I just have a trackpad, not a mouse. Anyway, the problem is that this way I can just move along two axes. To make this clear I took a video, which you can see here.

Like you see in the video I can only move just along the Y and Z axes, not along the X axis. If I wanted to move the user view in order to look at the back of the cube. I had first to rotate the camera and then move the visual again, which is doable but it's not fast/comfortable at all. I need a way (possibly a shortcut) to move the user view along the X axis.

You track forward/backward the same way that you scroll a web page. Often, a trackpad does this this with a two-finger drag up and down.

Note, that even when this works correctly, it will still not allow you to view the back side of the cube. By default, it will track toward an invisible pivot point i the center of the view. As it approaches that point, the track will become slower and slower, so that you never go past that point.

If you want to view the opposite side of you cube, you will have to rotate. But there is a setting that makes this a little easier. In User Preferences in the Interface tab, turn on "Rotate Around Selection."

This will force the view to orbit whatever object you have selected, instead of orbiting the center of the view. This will make it MUCH easier to just rotate around to the other side of an object. Check out the other options there, as many of them are very useful.


How do i change the dimension back to 2m on the starting cube The main cube is 2m so why is this one off

It seems like you have two objects "Cube" and "Cube.001". I assume that the "Cube" has dimensions 2m x 2m x 2m.
The "Cube.001" object consists of two default cubes of size 2m x 2m x 2m but because they are in the same object the object dimensions are calculated from their bounding box as can be seen in attached image. You can separate the cubes in edit mode (select "Cube.001" and press TAB button) by pressing "p" and selecting "By Loose Parts".


How to properly texture sculpted model I am trying to texture this model, But I didn't retopologize it because I found that a bit difficult.

This is what it currently looks like:

I put him in some armor:

I made an attempt to texture him here:

This blend file is a previous save because the current file is too big, What am I going wrong?

Mesh:

How would you texture him without artifacts?

So you need to know the basics of UV unwrapping .

UV unwrapping

https://www.youtube.com/watch?v=f2-FfB9kRmE

You also need to know how to texture , You dont need to texture it , you can also use materials but it isnt the best idea if you arent using it only for rendering :

https://www.youtube.com/watch?v=thYHF0282cE

Also be sure to look at lots of references and watch how other people do it :

https://www.youtube.com/watch?v=C3r2T7xU9Kw

there is also Clone painting , Shown in this video

https://www.youtube.com/watch?v=p4ngVoGIj1Q

And since you are beginner you might want to take a look at  basic texturing :

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


3D Manipulator hotkeys or addon? There was an addon where when you press crtl space it would bring up a menu for the manipulator. I found an addon for it called Manipulator Menu which you could hit crtl space and you could select from a pop up widget to use rotate location scale manipulator instead of having to click down on the bottom and I believe even if you just keep hiting crtl space it will cycle throw the 3 different transform rotate and scale. I had a virus alil while about had to delete everything of my PC and now I can not find this anywhere in the addons or even a working link.

I couldnt find the addon anywhere so my question is does anyone know a working link to that or if there is another way to do this so with like hotkeys or maybe like a script or something. I tried googling it and than addons forums at blender artists and even looked at http://blenderaddonlist.blogspot.com/ and not single one o them had a mod I could download.

I know it came from an older verison on blender under addons but now I cant find it for the love of me lol. If anyone can point me in the right direction for the addon or help me figure out how to change the keybinds to keys that arent used in blender. I have a logitech 8 button mouse but I just need to know what keys are not being used and wont mess up any of shotcuts. Hell if you have a work link that would be even better but I would appericate any help. Thank you!

Ok so I found the addon. It was in the 2.78 RC2 files like you said Timaroberts thank you. I was hoping I wasnt going to have to use the whole 3d pie menu thing because I dont really like it. The menu I got from the RC2 2.78 is a pie version- of it but oh well its only that one pie menu and not all the other ones. Heres the link if anyone wants it:
https://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts/3D_interaction/Manipulator_Menu
If anyone needs the file lmk I know I can stand going back and fourth with the manipulator lol so now I just have to hit crtl space and it works kind of like how the other one did expect this one has the pie radial thing and not just the menu but thats not a problem because thats the only pie menu =P.

Again thanks for the help. Hope someone looking for that addon from 2.77 can find this so it will help someone else to. Well thanks again =)


Blender 2.90 Alpha - Stereoscopy, how do i render interlaced output? When you turn on stereoscopy, then you will find the menu item Set Stereo 3D in the Windows menu. Here you can find other methods to display the stereoscopic image. Interlaced for example. The viewport displays the result then.
You can find similar settings in the Output panel in the Properties editor. But when i change the method and render the image, then the result is still rendered as anaglyph. And not as interlaced.
How do i render an interlaced result instead of an anaglyph one? And what is this settings in the output panel good for then? They seem to do nothing.
Kind regards - Tiles

"How do I render interlaced output"?
"Interlaced" is a viewing method.
When your window renders the image, it displays a composite.
If you need to further grade and edit your stereo footage (sequence):
You export a L+R sequence. Use an external compositor like Nuke, Katana or AE. Export side by side (up down or L+R) in the same aspect ratio you intend to view your stereoscopy (long technical explanation about 3D compression, format and playback inserted here).


How do you remove the line in the noise texture? I have a line in my noise texture when I render it, it's really visible. I'm using Cycles, with a spherified, subdivided, cube. I also let it smart UV unwrap, but the gap was still there.
blend file

You need to include a Displacement node.
Use the color mask you've generated as the Height input.

When you connect the color without conversion, it generates this line.
If we switch from Bump Only to Displacement and Bump we can see why.

(Note that I have only connected the Noise Texture to the Material Output in this image.  With the MixRGB node the effect is even more pronounced.)
Both the noise texture output and the color being Added are grayscale values, and when you attach a color directly to the Displacement input it treats it as Vector Displacement.  This means it translates the entire mesh some amount on all axes.  With the way I had my camera rotated it's going up left.
When Blender represents this type of mesh deformation in Bump Only, it is this sphere with a smooth line across the center where all the motion is "up left" and it's difficult to see the bumpiness.
Perhaps better put: if you consider that new diagonal the axis you're operating upon, those pixels at the "equator", as it were, aren't operated upon in a way that can be represented without actually moving them.


i cant edit collection, no object in collection i bring some Blend.file for kit bashing.

however some of collection doesn't have any mesh or material,

so i cant edit.

what should i do?

Did u directly open the blend file or append/import it? Can you share the blend file so that the problem can be understood properly?
Generally, a linked collection cant be opened to edit because the mesh isn't actually imported.


Why is the work top clipping out when i got to camera view? [full renderThe camera's location and rotation shouldn't cause it and it only happens in camera. I am the noobiest of noobs so please be polite and patient with me. I'm sure you will all say just scale it down but i really don't want to. Image of problem, worktop clipping out in corner behind monitor.Trying to add more pics from other angles but can't seem to so sorry for that. Probably to old for this.

I would guess it would be the camera clipping “end” isn’t set to a high enough value try changing it from 100.000 to 200.000 see if that works, under camera properties.


How do I show shading for test renderings Sample frame:

Until EEVEE gets into an official version, I'm trying different settings to test a character animation I made in cycles. Just good enough to see the character and floor shadows. No need for it to be super sharp it's just a test. I need the floor to see how the feet land. Her eyes have no lens so there is no transparencies to worry about.

1920x1080 resize @ 50% if lower difficult to see any details.

Multiple importance off.

There is only the floor and the character with a gray background as a light source.

Renders = 7 samples.

GPU rendering with my GTX1060 3GB
Tiles are maxed for GPU performance @480X270 = exactly 4 tiles per frame.
I got 0.99 frames per second.

CPU i7 2600K
Tiles are maxed for CPU performance @48X27 = exactly 40 tiles per frame.
I got 0.94 frames per second.

What else could I check or uncheck to speed that up even more?

Ambient Occlusion can be enabled for the Viewport, which can help visualize distances between objects, you can even turn it up if you need:


Unable to change specific faces color of a cube I want to assign a specific color to the faces, but I am unable to do that.
Upon assigning a color through materials, the entire cube turns that color. Please help!

First add an empty material slot to your mesh as shown below:

Add another slot
Add new material to the second slot and set it's diffuse color as shown below:

Switch to edit mode and select the face you want then select the material you created and click assign as shown below and that's it.


Particles fail when using Animation Nodes? I have the goal of trying to instantiate objects that emit particles, and have the new objects follow points on other objects.
My approach has been to attempt to use Animation Nodes. However, the add-on seems broken? I am following a few tutorials such as this one: https://www.youtube.com/watch?v=S3uschDguJk
As you can see, the basic idea is to instance an object with a particle emitter onto vertices of an animated object (or several). The instancing part works, but in Blender 2.8 and 2.9, the particles do not emit properly once the Object Output Transforms is used to actually move the instance objects onto the vertices. They do not move at all, and lose all interaction with physics or fields.

As you can see, the original emits particles with physics interaction, but the instanced objects (while generating particles) have them remaining stationary on the surface (and following along with the object animation).
In the above youtube video the behaviour is different.
I have also attempted setting location with the attribute node, but (once again) the actual placement of the objects work, but the particles lose any physics
Any advice regarding how to fix this - or alternatives? Many thanks in advance!

You can bake object transformation into keyframes using Set Keyframes node. It should work.
If you don't want to bake animation then try this method:
Step 1: Create empty objects using Object Instancer and do whatever animations you want to those empty objects.
Step 2: Create instances of actual object having particles using Object Instancer. Then unlink it from node. You can do that by pressing Unlink Instances From Node. which can be found on advanced settings of Object Instancer node. Then move those objects into another collection.

Step 3. Get objects from collection using Collection Info node. Then set empties as parent for these objects using Attribute Output node.


Rendering my freshly created diamond gives no good result I am a beginner at Blender and very enthusiastic about the enormous possibilities. It is a flood of options.
I started with the creation of a sparkling diamond as a part of a logo for my daughters business. I found a perfect youtube tutorial and succeeded making the diamond. After making the diamond I let turn the animated diamond. It looks very realistic! I am proud at myself! But...
When I start rendering the diamond animation or rendering the image I got a very strange result. See my image from the result. I tried in my opinion everything but no result.
I run Blender on my iMac Pro.
Who can help me?

The image shows the diamond animation in layout. It was constructed using a youtube video (Making Awesome Diamond Shader in Eevee - Blender Tutorial by VFX Mastro).
It looks for me as a perfect diamond!
Render animation shows on the left the red diamond output using the Evee engine and the output setting on the right side.

Purple = a linked image is not found.
so as @frederik wrote, it's something related to a material of the world (HDR image) that is not found by blender


Reverse an edge split? I applied an edge split a while ago on my model and now I want to separate parts of it. It's going to take me a long time to individually select each face because none of the edges are touching the other. So I can't use some of the auto-select features in Blender...

You can Tab into Edit Mode, key A once or twice until everything is selected, key W to open the Specials menu and select Remove Doubles.


How to model the top of helmet? How can I model this?I have it modeled from the front view, but how can I make it match the right view? What ever I do on the right view messes up the front view. How can I do this?
Thanks!

you can make your life easier with a mirror modifier and deleting 1 half of your mesh.
In side view (3), select the bottom loop (Alt+Right click on an edge), activate proportionnal editing with O and scale on Y axis (S, Y). while scaling, you can change the proportionnal editing radius with your mouse wheel. click to accept the scaling, right click to cancel.


How to use Shader Nodetree in emissions rendering? I am trying to render my image using a point light source. Now, I want to increase the brightness using node emissions. But, when I do so, I get an error. I have read the related questions here, but my problem is the of a point light source, not sun or material as before.
Attached are the parameters what I want to change and the error message.

.

I am using this line of code:
    bpy.data.node_groups["Shader Nodetree"].nodes["Emission"].inputs[1].default_value = 10000

Thank you so much! :)

In bpy.data.node_groups you will find node groups that you have made, that is nodes that you have turned into a group that you can use in multiple materials.

The nodes for a light can be found in the lights data property.

light_nodes = bpy.data.objects['lamp1'].data.node_tree.nodes
light_nodes['Emission'].inputs['Strength'].default_value = 10000


Reflection of floor materials I'm a Blender newbie, following a tutorial. The floor is dull, showing no glossy contrast like in the tutorial (shown in the lower part in the picture). Even if I raise the power of the environment texture to 17 as instructed, the floor is just all lighter, not having the contrast of shadow and light.

Anyone can help me with this? thanks a ton in advance!

You need a Glossy shader for this.

Open a node editor.
Go to the material tab (in the first set, looks like a ball), and then make sure you're in the object tab (in the second set, looks like a cube).
Select (right-click) the Diffuse BSDF node.
Press Shift+S and switch its type to a Glossy BSDF.

This will give you reflections. You can play with the reflection color and roughness until it looks right.

See the manual for more information on Cycles materials.


Color will be black when cycle redering material color is not not reflected when cycle redering
I change material color, but color is black when cycle redering.
when eevee, nothing problem.

I've found the issue.

You need to disable autosmooth normals in Object Data.

Properties->Normals->Auto Smooth uncheck


What file format do I need to export as I use Fusion360 to model and I would like to use Blender to render them. I just spent way too long trying to unwrap an imported STL file to apply a texture I just bought. Apparently it's impossible to ALT+click loops for a manual unwrap.

So my question is, what file format do I need to export as, in Fusion360, to be able to attach materials in Blender?

In general, the format should not matter as each is supposed to bring the same data into Blender, as long as the format is supported. The unwrapping though does not depend on the format.

Not that format does not matter, but it really has no influence on the unwrapping, as that is based on the geometry that is generated from the data read in/generated inside Blender.
While i usually use fbx or obj, i believe the format can be chosen based on ease of handling with all eventually involved software and their support of it.

Update based on the video in the comment:

The situation of not being able to select loops will come up if the geometry does not offer Blender a continuous edge flow, thus only the edge or only the edges to a certain part will be selected. Most likely caused by either N-gons or Triangle-faces. In that case one would have to manually select with shortest path selection Ctrl+LMB or change the geometry to a more quad-based version with a clear flow of the edges.

I'd suggest to un-triangulate manually if the object is not too complex and thus allow an easier workflow from there.

In regards of the format, i had both fbx and obj files i imported with quads, so in your case, try to export the objects without triangulating them.


Which one is a better approach Sorry for this beginner like question, but I can't find the answer since I don't know what I need to type in Google search. I have been learning to use Blender for the past few months, and I tried to make some low poly wooden fence for small houses

At first I created the standing part (I don't know what i should called it, sorry for my bad English)

and then put a plank right through the middle part

While it looks good, there are some parts of the plank that driven into the standing part, while it's not visible, I believe it's still rendered by the engine.

Since it's only a small object and few in number, I believe in won't effect the performance. However, in the future, I was hoping to develop my own simple and low poly game. If I ever used this as an asset for my game, will it affect the performance altogether?

After some thoughts, I separated the plank into parts, and placed them between the standing parts. Since it's a simple type (cube shaped) fence, it doesn't take much time to connect the vertexes together, but what if the fence is round type? I have tried to make a hole in the standing parts, connecting the vertexes, and it's time consuming.

My question is: considering the amount of time needed to work on, and how much it's affecting the render time process, would you rather drive a cylinder type mesh into the middle part, or doing the same thing as I did for the cube shaped fence?

When it comes to game assets there is one general simple rule. Use as many polygons as necessary and as little polygons as possible. No exception.

It's not only the amount of polygons but also the amount of vertices that matter. On top of that you also have to take the amount of UV islands for texturing (that means no "Smart UV Projection" or other fancy UV shortcut nonsense).

Also, don't assume the performance hit by the size of the object (in terms of screen space) in your finished game, neither the CPU nor the GPU care about that. They only care about the complexity as I described it above.

Continuous planks and bars (like in your fist example) through other meshes are the way to go, as long as they stay at the same position at their entry and exit points.


How to bevel a misbehaving corner? I want to add a simple rounded corner to this mesh, so I selected the corner and used ctrl + B to bevel it, but it bevels really strangely, it is very deformed.

Any idea what is wrong with it?

Blend file: https://files.fm/u/c5gd2hhc

Thanks

Your mesh topology is not good. You have inside faces (look into your mesh) – delete these.


How to put green screen video on a plane in Cycles All I need to do is place a video with green-screening onto a plane in a scene. Obviously, the green screen will need to be transparent. From what I understand, the video must be keyed and then exported/re-imported because Blender doesn't do keying while rendering. I seem to have successfully accomplished keying in Compositor, but now what? How do I apply it to the plane?

Most info I've found about the subject provides general guidance but doesn't describe the actual how to do it.

The scene is animated; the video must play with the rendered animation. The man will appear to be walking up the plank to the ship:

Using only the material nodes you could use the image texture's color components. With a good clean key background, just send the green value (alter contrast to taste) to a mix node and mix to transparent.

Here it is in action, with a very poor key background ;-)


camera animation with known distance between frames I'm trying to simulate a camera fixed on car which is moving along a straight path. I've been trying doing this using a curve path. The problem is that I need to know/specify exactly the distance the car/camera travelled between frames. Is there a direct way to do this?

I'd set the Scene units to Metric or Imperial (or metric, seriously). Then you would take your path length (ie. 50m) divided by the frames elapsed (ie. 100f) to get the camera velocity (ie. 50m/100f = 0.5m/f). Then you know that the camera travels 0.5m for every elapsed frame. Does that answer your question?


How do I create a shader that is partially emissive for a particular colour, but diffuse if it's grey? So, I'm trying to make some material that's like lava, with solid, diffuse, grey material, and an emissive shader that's red and orange, using a musgrave and colorramp node. This is a screenshot. How would I accomplish overlaying the the bright emissive parts over the black diffuse? Would I use a transparent colourramp or something?
This is a screenshot:

You need to plug another texture in the Fac port of the Mix Shader node, it will separate the emission and diffuse shaders, like so:


(Internal) Fire looks blocky in final render So I took a sphere, made it a smoke simulator, added wind and increased that to 50.00, and rendered it. For some reason it looks very pixelated.
3D Viewport:

Final Render:

Blender File:


Need advice to cleanup and rectify shading issues caused by boolean Need advice. I used union boolean to make this object, now need help to cleanup and rectify shading issues. Thank you

I can only reccomend the tutorials from Josh Gambrell. All of his youtube channel is basically about booleans and how to clean them up.
https://www.youtube.com/c/JoshGambrell


What is the best way to connect two cylinders at a 90 degree angle? I can't seem to find any method to fill this one model. Does anyone know?

Select the edges. Ctrl + E  or right click or Edge Menu > Bridge Edge Loops > add number of cuts and select Blend Surface. Adjust Smoothness as you wish


What does the “Global pivot” in User preferences do? What does the Global Pivot option in User Preferences do?

In the 3D viewport, we can choose between several pivot points: bounding box, 3d cursor, median point, individual origins...

In 2.7x, when you have more than one 3D view this option makes each 3D view use the same pivot option, when it is off you can change each viewport to use a different pivot point.

In 2.80 this option appears to have been removed, the pivot point is now always the same in each viewport.


Blender Fuzzy Camera Rendering Problem I am rendering a documentary project and the sampling size is really high for each image. All the images rendered don't look fuzzy but when I combine them together for a film for some reason they look fuzzy when the camera moves. What do I do to make it so it doesn't look fuzzy when the camera move?

You need to animate the Seed under Render Settings:

You can do this by hovering over it and pressing I, and then moving some frames, changing the value, and again pressing I.


Simple Deform giving wrong orientation I wanted to make a ribbed edge to a container lid. I started with a plane and subdivided a couple of times and extruded the a couple of sections. I then added the array modifier to give me the desired circumference and then used simple deform to wrap it in a circle. This is what I get.

I was expecting to have the ribbed edge outward, sort of like a cylinder. What I got was flat. I can't seem to find a combination of settings in array modifier or simple deform to make this work out how I want.
How can I change the orientation of the Simple Deform to make this like a cylinder?

Select your object, go in Edit mode and rotate it 90° on the X axis.


Glass material isn't transparent when looked through another glass material? I know that this question has been asked a LOT of times before, but none of the answers suited me, so...

This is a mesh  with glass material applied. And everything is perfect. I can see everything through clearly (just a UV Sphere behind mesh).

But when I add "liquid" inside, with the same glass material applied, it is not transparent.It is on the other hand transparent when i hide the cup, but when it is looked through the cup, it is not.

I use cycles, and I tried to tweak everything, but with no luck.
I would not like to reset blender to default, because I have startup file finely tweaked.

This appears to be because of overlapping faces. That is, two faces being in the same position. I cannot guarantee this is the case, but two transmission materials overtop of eachother sounds fragile.
I recommend either scaling the liquid block down slightly, or doing the following to change the liquid setup:
Make the separate liquid object just the surface.
Change the underwater part of the glass to a liquid-colored material that has a refraction index so as to match light going from glass into water as opposed to leaving air. You could probably get away with subtracting the IOR of glass from that of water, then adding 1. For a more accurate result, I'd have to think about the math, here's the law: https://en.wikipedia.org/wiki/Snell%27s_law If you aren't sure what to do, I might could look into it.
Hope this helps :D


I can't change materials I was making a scene in blender and I wanted to change the texture from "Material_1" to "Material_2". It lets me change it but when I go to rendered view the part looks the same. can someone please help me

Having a material as part of the list of materials for an object does not mean that it is applied to it.

In edit mode, select the material you want to use, then select the faces where you want the material to be and press Assign


How to render while in the compositor? In a tutorial at 3:22 the guy rendered while in node editor, but didn't say how.

I have tried other tutorials but they all don't say how to do this.

At 3:22 he renders the scene by pressing F12.

You can render by

Pressing F12.
Pressing Render image in Info header > Render:

Pressing Render in Properties > Render settings > Render:


Simple transform distorting loop cuts When I try extend the outermost edge of these panels using proportional editing (or simple transform for that matter) the loop cuts distort.

Can someone help me understand why—and how to workaround it?

I imagine that because the faces on the curved end are simply longer, it becomes apparent if you try to transform the shape. Ok, makes sense. But I’ve tried messing around with the proportional editing settings, the transform orientation, and the pivot point to no avail. It seems that Blender should be able to understand that a user would want to stretch this shape along the desired axis without distorting the loops.

Thanks,

John

So lets say i have this object that i want to make a straight loop cut in:

However, as you can see, this loop cut isn't straight, since the object isn't symmetrical.

Option 1: Straighten out your loop cuts

If you want your loop cuts to be flat along, say, the Y axis, then after selecting your loop cut, you can just do S > Y > 0 to make them flat in that axis.

Option 2: Bisect tool

What if your object isn't aligned along the axis? What do you do then? Or what if you are just too lazy for a two step process?

Well then you can use the bisect tool.

Select your object, and using the search bar (or some other method), select bisect. Then, you can just drag where you want your cut to be, and it will make a loop cut along that line!

The one issue with this is that it is hard to get a perfectly aligned bisection because your cursor is imprecise, but option 1 can help with that.


How to normalize the color values of a shader (Pointiness)? The contrast for the pointiness changes depending on the vertex density on the model. The Normalize node to have a value range of 0 to 1 isn't available in the shader editor. I thought it would be maybe possible to get this result with some Math nodes.

On the image bellow I am trying to get the same contrast between those two Suzannes, they have a different material each:

In order to map the pointiness values in the current view to a 0-1 range, a renderer would have to accumulate information about the entire frame or object, and then backtrack to adjust values between the maximum and minimum found. I'm confident Cycles can't do that.

There might be a more accurate method via baking and a histogram, but the approach I took to doing it by eye was to put the values through a color ramp, with the top 2% yielding blue, and the bottom 2%, red.

I then adjusted the 'Add' node to get a bare minimum of red, and the Multiply node to just hit the blue end. These were the figures for Suzanne, (top row), and Suzanne subddiv 2.

The top pair below were for calibration, the bottom pair the result with the color ramp taken out.

Maybe the regions would match more closely if we glue her eyes in.


Where to find fast DOF shader in BGE? I'm looking for fast Dof shader for BGE use. Maybe someone knows, where to find very similar to "Life is Strange" one. DOF could be without autofocus feature, I want simple like distance Dof like one. Would be great if it also has a bokeh effect.

Look like in this video...
https://dl.dropboxusercontent.com/s/vmm0o1j68ukwvlr/My%20Movie1.mp4

or in pictures;

What About this one?
http://devlog-martinsh.blogspot.com.es/search/label/DoF

or
https://www.youtube.com/watch?v=aehC81cYrjY

regards


How to change radius/weight of curve bezier? try scaling, change radius, but its dont work
scene link

First you need to apply the scale of your object because you must have scaled it in Object mode and it deforms it, so select it and ctrlA.
About the radius, you can either change the radius of the curve vertices or change the radius of the bevel.
For the curve vertices radius, go in Edit mode, select the vertices and altS, or in the N panel (on the right of the 3D View) > Item > Transform > Radius.
For the bevel radius, go in Edit mode, go in the Properties panel > Data > Geometry > and change the Depth.


Blenders node editor draws boxes when I try to connect nodes For some unknown reason, when I try to connect 2 nodes, from the cycles node group editor, I cannot draw a line, but instead it draws a select box what can I do against it?

I'm unable to progress my work now as I cannot finish the shader work, I cannot make a screenshot about it, its just as when one would make a group and had typed B (only I don't start with that crosshair cursor)

Blender 2.8x

Another way to join nodes is to Shift click the two you want to connect and press F.


How can I edit the values of modifiers on multiple objects at the same time? When I select multiple objects, an active object is selected automatically which gets the modifiers changes. How can I select multiple objects to edit their modifiers all at once?

If multiple objects are already using the same modifier, you can modify a value of it, which will be propagated to all selected objects, by holding the Alt key while changing the value or by AltLMB clicking into a field and entering its value.

Modifying properties of multiple objects simultaneously with Alt is not restricted to modifiers.


Trying to find the threshold setting for the Fill brush in 2.8 I'm drawing pixel art onto textures using texture paint and I want to fill in a certain area of the texture with a solid color with zero tolerance for overwriting any adjacent pixels that aren't the exact same color. It appears that 2.79 had the setting directly under the color picker as seen in this question: How to " no-flood-fill " a texture?

But I can't find the same setting in 2.8?

"Fill Threshold" is now in the "Advanced" menu :


copy python code of operation In blender, you can hold your mousecursor over a button to see both what it does, as well as the python code that it would run.

This is an amazing feature. But it still requires me to remember the code before I can copy it into a text editor. Is there a way such that I can press a shortcut and copy the code that is shown on hover?

In the case of the above screenshot, I would like to copy bpy.ops.object.material_slot_add().

At least in the lastest version of Blender, you can press Ctrl + C while overing any button (of sorts) to get the Data Path; This, however, doesn't work with Fields (text or numeric), since it copies the value that is already in the field. To fix this there's a "workaround", press RMB (right click) and select Copy Data Path, this however only copies a relative data path;

Also, it wasn't working in 2.72 for me, but I updated to 2.72b and it did.


Baking normals from high poly model to low poly issue I'm trying to bake normals from high poly model to low poly and here is the result

as you can see it bakes only the normals of low poly model

I selected my high poly first then the low poly and checked selected to active and the low poly model have smooth shading on it.I think there is something wrong but i don't know what is it
Note:when i baked normals the two objects were in the same place.

The problem could simply be in which order you selected the two meshes for baking. There are 2 levels of selection in blender when you select two or more objects: selected and active. The active shows with an orange outline whereas the other selected but not active object shows as darker orange/red. Make sure you first click on the high poly then on the low one when selecting:

BAD:

GOOD:

Note:

The baked normal map looks like it is for the knife on the bottom.  The area around the round holes seem like a smooth gradient whereas it that was the knife on the top poly, that area would show as flat.

You can see the issue in the mesh here:


Is it possible to expand/collapes all panels in a region with a keystroke or shortcut? In particular, I'm looking for a simple way to collapse all the N and T panels.  I'm using a number of addons and things are starting to get a little cumbersome wheeling up and down to find something so I'd like to collapse them all at once and then expand just the one I want.

If not, is there an API that could make use of?

thanks

Ctrl+LMB on a panel header will close all other panels.


Cycle does not reflect changes directly I was trying to paint a texture on an object in cycle, but i found that the changes will not be directly reflected in cycle. I have to switch to other view and back to render view to see the changes. May i know is it the nature of cycle or is there any problem in it?

Besides, is there any set up for the environment that is good for texture painting? Should the background be totally black, or placing lighting by myself, or just use a HDRI?

Thank You so much for helping.

You can use the Solid View for texture painting with some success if you are looking to really examine your painting in context of what you are changing in the specific texture. I set it to Flat and turn off shadows.

You can also use the Material View with blurred background, or turn on full background HDRI and lights from scene if you want to get a better idea of what your painting is doing in its interaction with your shading tree.

I think switching to Cycles render view is better for previewing the effect you have built up and to check your shaders, and not for the actual act of painting. The Material view has a very good result in comparison, and can be used as a preview of what it might look like before switching workflow to the shader tree for tweaking.


What's the 'disable in viewports'? I don't know difference between 'hide in viewport' and 'disable in viewports' in Blender 2.8 outliner.

What's the precise function of 'disable in viewports'?

And if possible, please explain the precise function of 'Holdout' to me too.

The Hide in Viewport option is just applied for the current view layer, whereas Disable in Viewports is global and applies to all view layers and viewports.

The change for Hide in Viewport is limited to the view layer as seen below

Activating Disable in Viewports in View Layer also affect View Layer.001 and all other view layers.


How to rotate a bone I am following a tutorial about how to make a simple stick man. Everything went fine until I reached bones. To follow the tutorial do I need to rotate all the vertical bones.

On the image I selected all the bones I need to rotate. I need them 180 degrees rotated.

(if you don't understand what I mean, here is a screenshot of the video)

Can somebody help me with fixing this?

the tutorial is telling you to set bones in the wrong position and then reverse many of them? anyway, you are in pose mode, that is intended to use when the rig is correct, and you wish to animate it. to correct the armature, you must me in edit mode...

so, select the armature, go to edit mode, select the bone gone wrong, press W and select "switch direction".


can you rig bezier curve im using bezier curve and bezier circle to make tubing. im using the tubing to make a body that looks like it was made of cables. can you rig the tubing to make it move like a normal model thats being animated
like an arm being moved

Enter in the edit mode of the curve, select a control point, use Ctrl + H as shortcut select Hook to New Object.

Blender will generate an empty as a helper get out from edit mode and select the empty and after that select the rigg enter in Pose Mode, select the bone that you want to relate the control point of the curve (or the emty object) and use  Ctrl + P , from the menu select Bone.
Repeat this for every control point of your character.

It`s hard if you have a lot of curves, try to trick it with other techniques.

Model the character in mesh, use Multiresolution and sculpt the tubes after you increase the multiresolution to 4 or 5. After you finish the sculpt reduce the Multiresolution to 0 for prewiev and 4 or 5 for render. Rigg the character.

Add 2 or 3 tubes with the bezier curve technique just for effect.


What would be some approaches to get low noise images from cycles with given render time for indoor scenes? For an animation of 10k frames I would like to find a tradeoff between render time and quality. With a given approximately render time of 1 minute per frame it would take 167 hours (a week, 24h per day) to render the full animation.

For outdoor scenes I simply increase the number of samples to achieve this.

For indoor scenes I use the Limited Global Illumination preset plus Ambient Occlusion and fiddle around the distance slider until the image looks 'bright enough'.

The lighting test scene has transparent windows, some emitting planes.

The results are:

with 50 samples (3 minutes):

with only 20 samples a lot more noise (~1 minute)

Which settings should be taken into account when trying to reduce noise for a given render time?

Completely different approaches are also appreciated.

Reduce max bounces to 4(you don't need more), Use filter glossy to maximum. Use like 50-75 samples. Try to avoid using roughness(it makes a lot of noise). Make object Mix shader and put shader in bottom, than set the factor. There are a lot more suggestions which should help.
Here
are some more things to use.


How to create a "heat distortion" effect with a cycles procedural node set up without compositing I know how to do a heat distortion effect in compositing.

What I am looking for is a way to do the same effect with a material set up in cycles.

What would be the best way to create a procedural material that can be placed in front of any object and make it look like heat is rising in front of it (without compositing)?

Any ideas would be greatly appreciated.

While it's not possible to vary the refraction throughout an object using volumetrics we can mimic the effect by varying the refraction at points on a surface and view the scene through that surface.

The Refraction shader affects the ray at the point of hitting the surface. If the ray hits the front of the surface then it is treated as a transition from air (IOR = 1.0) into the material, while if it hits the back of a surface then it is calculated as exiting the material back into air. Normally the ray would travel through the mesh, entering through one surface (bending one way) and exiting through another (bending the other way), resulting in the material acting like a prism. However, if we use a plane rather than a manifold mesh then only one side of the refraction effect takes place and we can use this to redirect the ray - as if it had passed through a lower density patch of air.

Refraction is dependent on the angle the ray hits the surface - with zero refraction if it's incident along the Normal and increasing refraction as the angle with the normal increases. We can use the 'Incident' Light Path property to determine the angle of the incoming ray and use this to manipulate the Normal of the surface to get the desired bending of the ray.

To achieve the effect, create a plane and add a new material to it. Open the node editor, remove the default Diffuse shader and replace it with a Refraction shader. Add a Geometry node and link the Incoming node with the Refraction shader Normal. This will mean that the Normal at any point in the shader will always be the same angle as the incident ray and will result in the surface behaving simply as if it were a Transparent shader (as all rays will hit it along the Normal and so no refraction will take place).

Add a Bump node between the Geometry node and the Refraction Shader to affect the distortion and feed this with your heat map as a series of images. Placing the plane between the camera and your scene will now distort the view to simulate heat haze distortion.

Note the addition of a Transparent shader mixed in for Shadow rays to prevent the distortion plane from casting a shadow. Also, ensure the Refraction shader colour is set to pure white.

For the heat map you can either use a Blender smoke simulation saved to a sequence of images or generate simulated smoke using a procedural texture. I used the following crudely generated heat map. This was generated using a Musgrave texture (and some noise), warped so as to taper towards the top, and masked off at the sides. It was animated by simply keyframing the Z-coordinate for the vector of the texture nodes.

This produced the following result :

See the attached blend files for details.

Heat Haze

Heat Map


Video Editing Markers I have somewhere (not somewhat) between 3 to 12 (that all indecates a variation from one number to a larger number, not a set of 3 or 12 film strips. which the words somewhat and the word 'and' indecates. I knew what I was speaking of. leave that alone Mr. MOD man)

I have somewhere between 3 to 12 film strips in Video Editing, then when I mark a point in the film, then I try to select a film strip to move it into place to find where I want to cut to that (different) strip, the marker gets grabbed instead of the strip even though I right click the strip and NOT the marker. It still moves the marker instead of the film strip for some strange reason that lays beyond my comprehension.

How do I get it to stop selecting a marker when I right click on a different strip?

To avoid moving markers, you need to move the mouse cursor away from the marker region at the bottom.

e.g. Here is an example for Select All operation:

Or you can toggle Lock Markers from Marker menu, to make them not editable / selectable:


How can I make a fluid simulation in game engine Is there a way to simulate a fluid in the game engine? It doesn't have to be 100% realistic (but not a cycling 2D animation). It just needs to be recognizable as water.

Optimally, there should be a way too make it not very computationally intensive, if it is by default.

No. You can't do fluid sim in BGE. Fluid simulation is a complicated process and won't run fast in real-time.

Only if it's built on a graphics card  system, such as CUDA or OpenCL, it might be fast enough. But Blender's fluid system isn't. You might want to check into faking it with particles.


Textrures missing when I export FBX I have a model I created with bones from Mixamo. The FBX has embeded textures.
I want to rename the bones in the model to get rid on the Mixamo in the beginning of each bone name. (this is find with Mixamo). I removed the Mixamo from the names, but then I export as FBX, the textures are gone. I am wondering how to reapply the textures to the model, or how to save the FBX with the textures.
Thanks for any help.

Ok, I figured it out. Download Autodesk FBX Converter (free). Run the converter. Add FBX Converter. Select Add. Now first select the FBX to be converted, then control select the Texture Directory. You have to do it in the order. Then on the right side, check Embed media. Then convert. You will have your FBX with embedded textures! Amazing how easy.


Blender 2.91.2 Transparency Effect no longer works with emission I use emissions to create flat renders, and I used this node layout in Eevee for images with alpha channels.

The above was provided to me by another user.
I've recently updated 2.91.2 and now I can no longer use this lay out. In the current image I'm using, I'm trying to render a checkerboard tile where the white spaces are transparent.

The original texture is png with alpha channel
But when I apply the same node layout I get a weird interpretation that isn't even transparent.

It instead creates a weird grid like wireframe effect. Why is this? Did they change how this works or am I doing something visibly wrong.
EDIT: I also went back to an older file, and the effect still works, UNTIL I apply it to a new mesh. By that I mean, copy and paste. Same image, same nodes, no alpha channel. HOWEVER if I use material copy via CTRL+L it does work. I am completely at a loss
Cheers!

Answer from a helpful person
"check when you press n in the material editor > options, if blend mode is set to alpha blend or alpha hashed. – Alex bries"


How do I open an editor window? I am working to create a specific design following a video tutorial. I can't anyhow seem to open the editor with the white check mark, in the image below.

If you want to open a Tool Shelf panel click the little '+' symbol on the left of the window or press the T button. You may open the Properties panel in the same way, but instead of pressing T, you press the N button.


Editing colors in Blender for vibrance and saturation Is there a way within Blender to edit colors, like Photoshop, using variables such as vibrance and saturation?
For example:

The image below is an photoshopped version of the first image, with vibrance +80 and saturation +2.
Is it possible to boost colors within Blender, without any post processing methods? (Such as those involving external programs, e.g. Photoshop)

Besides the postproduction options outlined in other answers, you can be intentional on how you use the elements instead of resorting to "fixing in post". You do have absolute control on the quality of the scene by careful crafting of the materials used and the lighting of the scene, without having to resort to additional effects.
If you want more saturated colors... use more saturated colors, or darker colors, in the shaders those are the ones that determine the color of an object in the scene, you have total control on how objects reflect light or how shiny they are. Also make sure that the intensity, and quality, of your lights is not making the objects too bright, and that is helping you get what you want.
Also play a bit with the different looks on the color management section. A higher contrast might be useful.

Read both answers on the following link very carefully:
Desaturated red when rendered
And read the whole page (comments and answers) here:
How can I get more saturated colors when I render?
To understand the relationship between brightness and saturation on the filmic color transform read this as well:
Render with a wider dynamic range in cycles to produce photorealistic looking images


Images and HDRIs are blurrier in Cycles I don't know if it is an error or not, but images and particularly HDRIs (the blurriness is more pronounced in these) lose detail and become blurry in Cycles, when compared to the Material Preview, or in EEVEE (same results).

This is the image in Material Preview.

This is the image in Cycles.

It may not be very evident in the images, but when it comes to HDRIs, the whole sharpness is lost - even for a 4k texture.
Why do you think this happens?

Increase viewport samples. and render it out. Maybe it's only because u r previewing the scene. The end result may be ok.


How may I get a single stripe of color to flow along an object? I'm toying around and trying to get a single red stripe to flow along the length of a cylinder. I'm trying to copy ideas from this tutorial, but I can't quite get it right. I made a gradient with three colors (white, red, and white) and I've got the bands of color being produced alright, but they're a bit skewed and don't line up perfectly with the geometry.
My aim is to incorporate this into some sort of abstract looping animation.
Think of an LED strip, and having just a single LED light up and go down the chain. I want to achieve that similar look using a cylindrical object, and a stripe of color. If I could get it to work with a bent cylinder (like one along a curve) that would be great too.
Any ideas?
Here's what I've got so far:

We can use the "generated" coordinates (from "texture coordinates" node) property: the coordinates are given before any modifier deformations. Using it can simplify what we have to do here.

Or with several rings:

The base shape is a tube/cylinder with a simple deform modifier to make to U shape:

And the node setting is the following:

Take Z value of the generated coordinates (remember this is still considered as a non bent cylinder)
Substract it to some value that will be animated to move the ring(s)
Keep positive value
Multiply (integer values) to have the amount of rings
Take module 1 to keep something between 0 and 1
Compare the result to 0.5 with an epsilon that gives the width of the ring

The documentation about generated texture coordinates:

Automatically-generated texture coordinates from the vertex positions
of the mesh without deformation, keeping them sticking to
the surface under animation. Range from 0.0 to 1.0 over the bounding
box of the undeformed mesh. See Texture Spaces for more information.


Animated textures on a mesh plane? I have a flat plane and a series of .png images that I want to have displayed on my plane as an animation.  I don't really know how to achieve this, as I've tried using "Image Sequence" on a Image texture node in the Materials section, which didn't work.  I enabled the AnimAll addon, but I cannot seem to find any tutorials that use the newest version of Blender (I'm using 2.91).
I'm relatively new to Blender, so any help is appreciated!

The images have to be named with the same base name followed by a number.

The simplest way to import them into blender is to use the Import Images as Planes addon.
File > Import > Images as planes.

Select the images you want.
Press N or click on the gear icon on the right of the window to enable the options and select Animate Image Sequences

Or manually add an image sequence node Add > Texture > Image Sequence. Set the number of frames and start frame.
Then just enable Auto Refresh.
To have the images on a loop, use Cyclic


How do I extrude perpendicular to a plane NOT oriented along X, Y or Z? I have a elbow pipe joint and I want to extrude the selected edges out to extend the pipe:

However, there is no convenient axis to restrict movement to.

Any ideas?

Press F to fill the face with an n-gon and then extrude.
Once a face exists the extrusion can happen along the normal of that face.
If you then want to move the face along that axis again you can change the transformation widget to the 'Normal' axis:

Allowing you to move like so either by using the widget pictured...

or by pressing G,Z,Z.
You can then delete the face after the extrusion is complete via X.


Single slider for transparency in Material Preview/Rendered display My users would like to be able to adjust the transparency of their mesh objects with a single slider in the panel of an addon, where the transparency ranges from invisible to opaque.  The desired functionality is exactly like the functionality of the alpha channel of the diffuse color in Solid display mode:
mat = bpy.context.object.active_material
row.prop(mat, "diffuse_color", text="color+alpha")

However, we also have image textures in our scenes, which are only visible in the Material Preview or Rendered display modes.  Is there a way to reproduce this one single slider functionality for a transparency that is visible in the Material Preview/Rendered display modes?
More details:
I have been using a Principled BSDF node, but there are many different settings for the transparency, and none of them range from invisible to opaque.  If Blend Mode = "Alpha Blend", then the object is never opaque, but if Blend Mode = "Opaque" then there is no transparency.  The alpha channel of the Base Color is more helpful than the Alpha input of the BSDF node, but neither of them range from invisible to opaque.  And there are several other color settings, but none of their alphas help to achieve what I need.  I'm hoping that I've been searching down the wrong path, and there is actually a simpler way to deal with transparencies that is visible in the Material Preview/Rendered display modes.
Thanks for your help!

Following Gorgious' solution, I am now trying to link the full diffuse color as well, using the same method.  However, the resulting color isn't correct, I think the problem might be with deleting the variable and creating a new one for all three color channels, but I'm having trouble determining the data structure:
def attach_color_driver(mat, rgb_ind):
    color_input = mat.node_tree.nodes["Principled BSDF"].inputs["Base Color"]
    driver = color_input.driver_add("default_value")[rgb_ind].driver
    [driver.variables.remove(value) for value in reversed(driver.variables.values())]
    var = driver.variables.new()
    target = var.targets[0]
    target.id_type = 'MATERIAL'
    target.id = mat
    target.data_path = "diffuse_color[" + str(rgb_ind) + "]"
    driver.expression = "var"

attach_color_driver(mat, 0)
attach_color_driver(mat, 1)
attach_color_driver(mat, 2)

This displays green as green, blue as cyan, and red as green.

If you don't mind not being able to directly tweak the shader's alpha in the shader editor, you can set a driver between the viewport display alpha and the shader alpha. Note that you can also set it the other way around, drive the viewport alpha with the shader alpha.
import bpy

obj = bpy.context.object

mat = obj.active_material
# Make sure the material has a principled BSDF (replace with appropriate node name)
if mat and mat.use_nodes and mat.node_tree.nodes["Principled BSDF"]:
    alpha_input = mat.node_tree.nodes["Principled BSDF"].inputs["Alpha"]  # Store access to the alpha input
    driver = alpha_input.driver_add("default_value").driver  # Create a new driver and store it
    [driver.variables.remove(value) for value in reversed(driver.variables.values())]  # Clear the driver
    var = driver.variables.new()  # Add a new variable

    target = var.targets[0]  # Access the first driver variable and set appropriate paths...
    target.id_type = 'MATERIAL'
    target.id = mat
    target.data_path = "diffuse_color[3]"
    driver.expression = "var"

Result :

As an addendum, if you want to drive the principled BSDF's color with the viewport display color, you have to add a driver to each of the color property's dimensions. Here's how to do it. Add these lines at the end of the previous code :
color_input = mat.node_tree.nodes["Principled BSDF"].inputs["Base Color"]
for channel in range(3):
    driver = color_input.driver_add("default_value", channel).driver
    [driver.variables.remove(value) for value in reversed(driver.variables.values())]
    var = driver.variables.new()

    target = var.targets[0]
    target.id_type = 'MATERIAL'
    target.id = mat
    target.data_path = f"diffuse_color[{channel}]"
    driver.expression = "var"

Result:

As a side note, you don't have to clear the driver variables, but it does not automatically get removed when accessing this particular field's driver (I think), and if you try adding new variables to a driver without checking first if it already has some, it will simply add more and more. That could lead to some serious bloat if you accidentally run this operation multiple times.


blender closes on startup I'm using an i9 desktop computer and a graphic card of Intel® UHD Graphics 630 with a Quadro rtx 4000. Currently I'm using blender 2.83 but anytime I try opening it, it shows me a black screen an it immediately closes. it doesn't open, please what do I do.
many thanks

Start blender from a terminal.  And see if any errors show up.
https://docs.blender.org/manual/en/2.79/render/workflows/command_line.html
Platforms
How to actually execute Blender from the command line depends on the platform and where you have installed Blender. Here are basic instructions for the different platforms.
Linux
Open a terminal, then go to the directory where Blender is installed, and run Blender like this:
cd <blender installation directory>
./blender

If you have Blender installed in your PATH (usually when Blender is installed through a distribution package), you can simply run:
blender

macOS
Open the terminal application, go to the directory where Blender is installed, and run the executable within the app bundle, with commands like this:
cd /Applications/Blender
./blender.app/Contents/MacOS/blender

If you need to do this often, you can make an alias so that typing just blender in the terminal works. For that you can run a command like this in the terminal (with the appropriate path).
echo "alias blender=/Applications/Blender/blender.app/Contents/MacOS/blender" >> ~/.bash_profile

If you then open a new terminal, the following command will work:
blender
MS-Windows
Open the Command Prompt, go to the directory where Blender is installed, and then run Blender:
cd c:\<blender installation directory>
blender

You can also add the Blender folder to your system PATH so that do you do not have to cd to it each time.
You can also try to reset user preferences (this will reset blender to stock)
https://www.katsbits.com/codex/userpref/


Should I update Blender? I have blender version 2.76b. I have noticed that blender doesn't update it self automatically. Is there a reason for that. And also if i update my blender, will I be able to work on blender projects from previous version of blender without any errors or problems? Thanks

Blender as no builtin automatic update system at the moment, you always have to download and manually install new versions.
They are for the most part backwards compatible except for major versions like the jump between 2.49 to the 2.5 series, or between 2.79 and the 2.8 series. Apart from some small additions or changes you should always be able to open your files without problems on newer versions unless stated in the release notes.
If there is no particular functionality from the dropped features list you specifically need, and if your hardware is compatible with newer versions, it is always advised to upgrade, unless you are in the middle of some critical project, commercial production work, or a complex scene, in which case you are advised to finish your work before messing with the software installation.
New versions can bring bugs and introduced regressions or some time have issues with newer driver and hardware.
If you want something close to an auto update system you can try the Steam version of Blender.


Boolean Modifier Help - Difference - Surface Remaining I'm very new to Blender but I'm trying to create a simple facemask.
I am using a Head Mesh (using FaceBuilder add-on) and a simple hallow cylinder to create the profile of the mask that will sit against the face.
I have intersected the cylinder with the face and have used the Boolean Modifier with the Difference Operation to create a cut in the cylinder using the Face mesh.
The problem that I am having is that the front of the face is remaining after doing the Boolean Modifier.
Is there any way of removing this? Maybe I am misunderstanding/misusing the Boolean Modifier.

That should work using 2.91 version of Blender with "Exact" option for the boolean:

"Fast" option behaves as the boolean of the previous version.


How do I get the object to the ground floor grid? I have an object that is far away from the starting point grid. When I Add a Bezier Curve, it is on the grid and switch to Top view, it is too far away to see and manipulate. How do I get my object in the center of the grid so I can do the curve-the-object around the Curve trick?

Sometimes it is difficult to locate the exact location of your object in the 3D editor.

You can directly set a number of properties for Meshes and other items in the Properties Panel.

The Properties Panel can be toggled with the 'n' key in any 3D view(and a number of other views).

To set the Location to 0 for X,Y,Z click and drag from the X input box to the Z so they are all highlighted. Then just type 0 to set them all to the same value.


2.8 Can I automatically remove all vertex groups that are not influencing any mesh? When I assign Apply Automatic Weights I want to then delete all unused vertex for simplicity sake when my character to rig is composed of many mesh parts.

The Delete Unlocked Vertex Group option helps but I wish I didn't have to delete hundreds of vertex groups by hand to begin with. I know sometimes a character to rig is one mesh but for when it isn't I wish there could be a way to just have vertex groups created only if they are influencing the part of the mesh.

eg: I don't need feet and finger vertex groups for the head mesh.

Ideally, if I can remove all vertex groups that are not influencing any mesh with one click would be optimal.

Is there a script or add-on that can help me speed up removing unwanted vertex?

You can just:

select your skeleton
get a Text Editor window
paste the script below & run

import bpy
bpy.ops.object.mode_set(mode='OBJECT')
skeleton = bpy.context.object

for object in [object for object in bpy.context.scene.objects]:
    if object.type == 'MESH' and len(object.vertex_groups) > 0 and skeleton == object.find_armature():
        for vGroup in object.vertex_groups:
            if skeleton.data.bones.get(vGroup.name) is None:
                object.vertex_groups.remove(vGroup)

I still think the first answer is valid for those searching & do not feel comfortable running scripts to just mass delete everything in advance.  Hence the 2 answers. The question was a year old, and I also assumed the original asker had moved on.


Compatibility of AMD Radeon ProRender Is the AMD Radeon Pro 5300M GPU in my 16” MacBook Pro (with a 2.6 GHz 6-core 9th generation Intel i7 processor), compatible with the AMD Radeon ProRender plug-in for Blender ?
The Blender Developers Blog states “macOS 10.12 or newer is supported” [April 30th, 2019]. While the AMD Radeon website lists MacBook Pro (Mid 2012 or newer) as compatible.
I’ve found several online posts discussing the 8-core i9 processor but I’ve yet to find a discussion about the 6-core i7 processor.
I prefer to err on the side of caution, as you might imagine, I don't want my notoriously expensive shiny new Apple to burst into flames when I hit render.
Thanks, I look forward to your responses.
[PC vs MAC debate free zone ;-)]

TL;DR: Yes, you can use the AMD Radeon Pro 5300M for GPU rendering with the AMD Radeon™ ProRender, if you're using macOS 10.13.3 or later.

There are two relevant requirements:

The minimum requirements for running Blender
The minimum requirements for AMD Radeon™ ProRender for Blender

Minimum requirements for running Blender (2020-08-07)
You will need macOS 10.12 or later for starting Blender 2.8x and macOS 10.13 or later for Blender 2.90. Additionally a GPU is needed that is GCN first generation or later, which is the case for your GPU from the Radeon Pro 5000M series.

Minimum requirements for AMD Radeon™ ProRender for Blender (2020-08-07)
According to AMDs website the following requirements have to be met:

Blender® 2.80, 2.81, 2.82, and 2.83 (experimental builds not supported) for Microsoft Windows®, macOS®, and Linux®

macOS® High Sierra 10.13.3 and up (10.13.4 required for external GPU support)

Runs on both GPUs and CPUs. OpenCL™ 1.2 support required for GPUs on Windows® and Linux®. Metal® 2 support required for GPUs on macOS®

Compatible Apple® Mac® Hardware:

MacBook® (Early 2015 or newer), MacBook Pro® (Mid 2012 or newer), MacBook Air® (Mid 2012 or newer), Mac mini® (Late 2012 or newer), iMac® (Late 2012 or newer), iMac Pro™ (Late 2017 or newer), Mac Pro® (Late 2013 or newer) (Models without discrete AMD Radeon™, Radeon™ Pro, or AMD FirePro™ graphics will be limited to CPU rendering with Radeon™ ProRender)

In summary, if you fulfill the following requirements, you're able to GPU render with the AMD Radeon™ ProRender:

MacBook Pro is from mid 2012 or later
Operating system is macOS 10.13.3 or later
Blender version is 2.80 or later, but not 2.9x yet


"Smooth Vertex" wrinkles mesh instead of smoothing it How is this smoother, it keeps wrinkling everything like forking pie crust

pie wrinkles http://ball2000.net/blender/images/GeeThanks.jpg

This tool doesn't seem to like ngons (faces with more than four vertices).

Assuming you want to make the outer edge circular, instead you might try using To sphere
(⎇ Alt⇧ ShiftS):

Or you might try the bundled loops tools addon.


How to manage Handlers in an add-on? What is the best way to manage handlers in an add-on?

I am making an add-on that uses the scene_update_pre handler. In the register() function, I have added this line:

bpy.app.handlers.scene_update_pre.append(my_handler)

The issue is how do I setup the unregister() function to remove the handler if the add-on is disabled? I can't use pop because it might mess up another add-on, correct?

Whats the best practice when making an Add-on?

It is simple:

def unregister():
    bpy.app.handlers.scene_update_pre.remove(my_handler)

Blender will call unregister() in the moment you untick the addon in the User Preferences.

my_handler is a function in the global scope of your script, and you append it to the scene update handlers. You can remove it in the same way, by giving a function reference to remove(). It doesn't work if you try to remove a handler callback from outside, because another script hasn't the same function.