How does fac differ with manual control versus node control?

Using the slider will just give one value for the entire surface (or volume, now that we have volume rendering :)

Using a texture will give multiple values mapped to different locations (the  depends on the texture mapping of course):

Basically the texture is supplying a value between 0-1 per ray.

Think of it this way: Each "light ray" cast from the camera by cycles that hits your object will test to see if the mix shader is resulting in shader 1 or shader 2. If the texture controlling the factor is black (0) where the ray hit, it will bounce off the diffuse part of the shader. If it is white (1) where the ray hit, it will bounce off the glossy part of the shader.

So, you can use anything which results in a value (which is pretty much anything). However that's not to say that everything will give a meaningful or useful result.

Note that even if the factor is somewhere between 0-1, the ray will only sample one shader at a time (if you are using the progressive integrator), but with many rays sampling the same point it will converge to a pixel which is a mix between the two shaders.


Boolean modifier difference but without filling in faces along the created "holes"

You could add a Solidify Modifier before the Boolean. Also, add a Weld Modifier after the Boolean.
Use a very small Thickness in the Solidify and make sure the Distance in the Weld is high enough, so that the newly created vertices from the Solidify get welded back together.
Regarding the Shading: That should go away if you enable Auto Smooth.


How to reduce poly without losing the shape

Try using the Decimate modifier shown below:


For library linking use groups. Let's I show an example:

In library file select all part in your object and press Ctrl+G. And in side T-menu or in F6 set name of the group:

In main scene file add group to the scene. It's like adding object, but you select "group" instead of "object".

After this you will get an empty object with duplication of linked group, that you can move, rotate and scale as a regular object:

And also you will get this instance in add menu:


A polygon-rich approach
I gave it a go with a shower of particles. This may be a little bit too resource-intense for just a background feature though.
The setup
I created a simple "room" with

a double-layered window (two plane meshes);

a plane out in the sky, almost vertical, with a particle system;

two strong wind force fields that push the particles toward the window;

a simple icosphere as a dupliobject.

The building and the inner window layer are set as Collision objects with "Kill particles" activated.
The outer window is a Collision object with very high stickiness (no kill), and high damping/friction on particles.
The particle system has strong Normal velocity and low Gravity field weight, so that the rain drops don't fall off screen too quickly; "Object" > "Icosphere" is selected as "Render" option, with "Emitter" un-checked.

(this preview is from an earlier version, with less particles and less friction on the surface)
The render
By giving the icospheres and window layers a Principled shader with very high transmission; adding some orange streetlamps and violet "dusk" sun (and a sad Suzanne in the storm); with some DOF and motion blur: this is a very rough result:

     (Only 7 frames)
Using nodes and a "Geometry" input, I made the raindrop's shader completely transparent (shadeless) when the "y" coordinate is less than y0 (the position of the window) to cut away the part of the sphere that "permeates" the first layer.
This answer's blend file

Even heavier for a close up shot (with metaballs)
If you want a close-up shot as in here, an additional Particle System with similar physics, but from a nearer plane (just near the camera) and with big meta-balls as DupliObjects, can help:

Result:


How to make the arms of a rigged character slide on the surface of the body

For Cycles, a trick would be to use a distinct mesh for the arm and use the Bevel node. It will create the illusion of bevel where the meshes are joining, so you'll be able to move the arms however you want and they will still be looking like they are part of the body. Keep the Radius value low (here 0.1).

In Eevee (or Cycles) you could try with a large topology around the arm joint so that it has latitude to move. Give it a Shrinkwrap modifier with a sphere as Target so that it stays spherical:

Or you could use the arm as a distinct object and try the Shrinkwrap modifier, with the Wrap Method > Surface and with a group assigned where the arm is supposed to stick, but it looks hard to get good result:


Render is working locally, but not on the server

The blend file doesn't save a lot of things into it: images used as textures (unless packed), simulations caches (smoke, particles, physics) or video files.

Simulations need to be cached to disk and made available on the remote computer.

Set your project to use relative folders. Bake the simulation to disk on your local computer, upload the cache folder along with the blend file to the server.

Just like cached simulations, all other "external" files need to be made available to the server when using remote rendering.


In this non-destructive workflow, your object is still considered by Blender to be the original little cube: the Simple Deform just "happens" to it, and can be still tweaked, changed, removed. The circle is not really there, is just "computed" on the go from the starting cube every time.
This saves memory and allows "customizability", but requires you to think of the object as a little cube with some other thing happening to it. It becomes very clear if you enter in Edit Mode (Tab) and realize that you only have the original cube's vertices only.
If you want to set the transformation in stone, and have your actual circle with all its vertices, you can hit "Apply" in the modifier options. After doing that, you can use CtrlAltShiftC > "Set Origin: To Center of Mass" to correctly place the pivot to the object's center.

P.S. there are alternative ways to create a square-section circle: e.g. using the Spin tool or the Spin modifier, or using a Bezier Circle with a square Bevel object, or this one (I think it's the easiest) that starts with a torus:

Add a Torus
In the "new object" parameters (F6) change "Minor Segments" to 8
In Edit Mode (Tab) select the unwanted edge loops (CtrlShiftMouse Select)
X > "Dissolve Edges"

All these methods have the pivot in the right place


Multiple character instances with BlenRig workflow?

Since Blender 2.81, a new feature has been added in order to overcome the limitation of one same rig per scene: library overrides.
It's only the first implementation and officially considered as experimental, it is still limited and it's planned to be enhanced in the future.

You can learn more on the manual


Having more than more animation on one rig

Change from dope sheet to action editor and add actions (animations).


Project Video onto Sphere in Video Editor

In this example I have created a simple UV sphere in 3D and subdivided it a lot to make it smooth.
Then I used the addon "Import Images As Planes" to make a plane with the picture. I rotated that 90 degrees to vertical then oriented and placed it at the surface of the sphere.
I apply 2 modifiers of "simple" subdivision set to 3. This will make the plane smooth when it deforms to the sphere. Then I applied the Shrinkwrap modifier set target object to sphere.

I created an Empty object at the centre of the sphere to do the rotation work, then I parent the plane to it (remember to select the parent object last then press CTRL+P). To move the image plane simply rotate and keyframe the Empty object. In the scene properties make sure that it is set to Transparent.

In the VSE I add the prerecorded video of the actor or scene, then I add a "Scene Strip" on top. I set the strip to Alpha over and change the blend amount to approximately 0.5.

If you want the wrapped plane to go behind the actor you will have to shoot them on green screen and key them via the compositor or use a mask to draw around them and hold out the 3D imagery.


In Edit Mode, Select all - A, press CTRL+E > Clear Sharp.

They are Marked Sharp and this is why it looks like this. It happens sometimes when importing .OBJ files or other formats.

You can also check Data tab > Geometry Data for Custom Normals, they can cause troubles but they can also be good. So if want to get rid of them choose Clear Custom Split Normals Data.


Blender 2.8 greasePencil Poly and surface drawing

When you select a Grease Pencil Object and switch to the draw mode, an Origin dropdown menu is available at the top right of the window.
You can choose your stroke placement there!


AMD Radeon cards do not have CUDA cores or OptiX, those exist only in some Nvidia Cards. Blender cannot enable what doesn't exist in your computer.
Your hardware is based on a different technology by different company.
Your only option to render ion cycles using GPU is OpenCL.


There's no camera on the timeline in 2D animation


Is it necessary to convert a python script from bpy.context / bpy.ops to bpy.data to run it withou gui via command-line?

bpy.context works perfectly fine from the command line. Here is a set of scripts for doing useful things with Blender from the command line, and a couple of them (render-batch and apply-compositor) make references to bpy.context.

Note also the technique of wrapping the Python code in a shell script, so the user can conveniently invoke the scripts as though they were commands in their own right.


Why when I unwrap my model does the field for the Torso come out so strange?

I am pretty sure you are unwrapping the mesh wrong. You have it unwrapped in a sort of round ball shape on the UV map. If you unwrap it with cylinder projection, cube projection, or even just select one side of the chest and unwrap it that way, it will be more square-like/flat. That would work a bit better and you would not have stretched textures.


Create an empty and turn on face-snapping with influence on move and rotate before snapping it to your rotated plane(empty is aligned):

parent the rotated plane to the empty and finally set the rotation of the empty as 0, 0, 0 before clearing the parent-relation:

explanation: the problem with the snapping without the empty is that there are no object rotations in Edit Mode, but only single vertices and their locations. If your rotation in Object Mode is applied (0,0,0) or not represented in the Edit Mode transformation of your rotated plane, then there is no difference to align to an other object also having 0,0,0 rotation in Object Mode. Only the transformation of the of the new empty (0, 0, 0) to the normal of your plane allows to rotate the plane in relation to this newly formed difference.


Drawing in 2D using a reference image, strokes keep appearing behind the reference image

The option to solve your problem can be found in the Object Data Properties of the reference image object like in the picture below:

to get there you need to switch in object mode and select the image reference object

There is also an option to set the reference image to be in the front, BUT using transparency.

Happy Blending


UV Textures being distorted on rendering

Your problem appears to be the UV coordinates you have assigned.

Select your "Panel" material. Click the textures tab. Scroll down to "Mapping". Set coordinates from "Generated" to "UV".

This will solve the issue.

To clarify the problem:

When you generate UV coordinates, you also have to go into the Texture's settings, and say you want to use those UV coordinates to map it, not the default generated coordinates.


Object Mode Snapping:

Center
When in Object mode, "Center" for snap means taking the current Pivot point setting of your selection, which also means the transformation center, not the bounding box center of your selection.
Median
As for "median", it means the same as the Pivot type Median.
Median means a sort of center of gravity of the selection. The behavior is most obvious with an  asymmetric selection:

There is one way to get the same result by using "Center" and "Median" snapping,  which is when using Center snapping mode, if your Pivot point setting is Median, then it behaves the same as when using "Median" snapping mode.
In any other case, they will not be same unless your selected objects are distributed perfectly even with each other.
Vert/edge/face

Vert/edge/face are only available in Edit mode. So, don't think about it in Object mode, when in object mode, unless you are using "Closet" as snap target (available for vertex). your snap target "Active" will only be the origin of the one you selected last. Furthermore, make sure you do have a object that is selected and activated, otherwise blender has nothing available to snap, but to use "Median" point as the alternative one.

I hope I've tried my best to answer every point in your question. Of course, if any question, just throw it here, we'll try to offer further help. :)

P.S.: If you really need to snap certain element (vert/edge/face) in Object mode, you may consider switching to Edit Mode first, place/snap 3D cursor to wherever you want, then go back to Object Mode, using Center as snap target. Then switch Pivot point to 3D Cursor, which may behave as you expected.


Glass texture has Voronoi like texture on it when using glass BSDF

The model is a mess. When you download models created by other people you are always prone to inherit a lot of buggy geometry and bad modelling habits of the creator, plus those created by the translation into different formats.

The particular model is plagued with duplicated geometry, hence the z-fighting. All of those dark triangles that you see are not only on the windshield but in every surface, are caused by overlapping vertices

You need to do "remove doubles".

The normals are all messed up (in edit mode select all of the vertices and make them consistent (Ctrl+N).

On top of that, whenever you are dealing with glass you need it to have some thickness (see this link: https://blender.stackexchange.com/a/69616/1853)

The glass shader you are using makes no sense. See this link for a proper  shader: How to illuminate the darkness inside glass objects in Cycles?.

The scale for the object is also wrong.

There is probably more, but that you will have to figure out on your own.

If you are doing experiments with textures, first make sure that the model you are going to use is decently crafted so that you can focus on the textures.


In UV Editor open N-panel (N key) and enable Normalized


Import and exported File have different sizes though they are identical

Blender's .ply importer can handle two kinds of .ply file.

ascii  (plain text -human readable, but large file sizes)
binary (data is stored in a compact way, and must be decoded before it becomes human readable)

Blender exports neither .ply or .obj as binary, so expect larger file sizes as exports.


How to apply the ocean modifier to get an animated object?

Export the mesh as an .mdd file format.
Remove any deformation modifiers on the object. Apply the Ocean modifier. The object needs to have same amount of vertices as while exported but strip down any animation on it.
Add Mesh Cache modifier and import the file into it:

Now you baked the object's animation. Tadaa!
You can also apply your modifiers as a shape key. To do this for every frame you need to do some scripting though.


Blender game: How can I make a ball roll while moving?

Torque causes rotational motion; therefore, applying torque will make the ball roll. This can be done with logic bricks or with python.

For both ways start out on the ball's physics, set Physics Type to Ridge Body and adjust the radius to the the size of the ball.

Logic bricks

Then on the ball add a Motion actuator. On the motion actuator, uncheck use local torque (the L on the right) and set the torque on one of the axes.

Connect keyboard sensors to the motion actuators with corresponding torque for the axis.

Python

Using python, create a text block and add this script.

from bge import logic, events

cont = logic.getCurrentController()
keyboard = logic.keyboard.events

x, y = 0, 0

if keyboard[events.UPARROWKEY]: x += 1
if keyboard[events.DOWNARROWKEY]: x -= 1
if keyboard[events.LEFTARROWKEY]: y += 1
if keyboard[events.RIGHTARROWKEY]: y -= 1

cont.owner.applyTorque((x, y, 0))

Then connect an Always sensor to a Python controller and activate TRUE level triggering.

Result
The logic bricks or script will roll the ball. *This is a monkey shaped ball.*


There's currently no simple/automatic option in Blender to have light probes change/bake over time, so you have to do it via scripting.

Select the Scripting workspace
Create a New script
Copy, paste, and modify the below code: change the Path value to wherever you want to output your animation frames, and change the range of frames you want to output. The sample below will save frame 0-29 (does not include 30).

import bpy

scn = bpy.data.scenes["Scene"]
com = bpy.ops.scene
path = "d:/blender/output/frame_"
i = 0
for i in range (0,30):
    scn.frame_current = i
    com.light_cache_bake()
    scn.render.filepath = path + str(scn.frame_current)
    bpy.ops.render.render(write_still=True)

Run the script (click Run Script or the play button, depends on version)

Basically what this is doing is going through each frame, performing the "bake indirect lighting" option (the one you manually click under the Render settings), rendering the frame & saving it as frame_0.png, frame_1.png, etc. So it will take a while and there's no "cancel" option, so I'd suggest testing this with a short range of frames to begin with. It may appear as if Blender has crashed, but if you keep an eye on the Path folder, you should see files start to be saved as they render.

When using this method, I only use it for the frames where the lighting changes. I wouldn't want to output the entire animation like this (ie, baking each frame when nothing changes). So I might render frame 0-100 normally, then if my light probe needs to change on frame 101, output frame 101 to 110 with this method, then render the remainder normally & composite everything in After Effects later.

Full credit to the person who came up with this method, as demonstrated here: https://www.youtube.com/watch?v=aAAb6sITkq4

Hope this helps!


The hard way
But the way you can use to pour sugarlicious material on.
As usual we'll begin with a simple vertex. Easiest way is to add a cube, or plane, and go into edit mode, vertex select mode, select all with A then Right Click > Merge > At Center.

Add a Displace modifier set to X, lower the midlevel and increase the strength. Don't mind the vertex group, you don't need it.

Add a Screw modifier, increase the screw, iterations and steps (viewport and render)

Let's give it some thickness ! First add another screw, but set the steps to 1.

How to create a noodle. Don't worry about the wonky shading just yet.

Add a Bevel modifier set to angle and crank up the width. Add a Weld to remove the seam in the middle.

The tricky part. Add an empty, set it as the object offset in a new array modifier. Now we drive the empty rotation so that the result is always equally separated.

Set the array count to 10.

Add a Bezier curve, scale it. Add a Curve modifier to the other object, and set the curve as the target.

Let's shade this masterpiece ! (Easy part)

What the ?? Everything's white !

Let me show you the simplest magic trick in the book. Offset UV in the Array modifier.

Final result :

I'll let you play with the settings, not all the fun for me :)


Convert large particle system(s) to one object efficiently

Particle Instance modifier

  When a ParticleInstance modifier is added to an object, that object will be used as a particle shape on an object which has a particle system associated with it.

Instead of setting the leaf object in the render settings of your tree's particle system.
Use the "Particle Instance" modifier on the leaf itself.

This has the advantage that it can be used multiple times for multiple particles systems.


Has anyone edited the blender source code to enable unlimited undo's?

The Undo feature in the blender works by storing a copy of the file inside computer memory for every single thing you do. It means that you really can't have infinite undo steps availible. However, you can increase it to a very high number.
Goto Edit->Preferences->System, and then change the value in "Undo Steps" under "Memory and Limits".


You have nothing controlling the factor of your mix shader. You need to use the alpha channel of your PNG file to control how the mix factor, so that the transparent parts are not mixed in.


You have use_uv_select_sync on. You're moving both UVs because they're the same vertex on the mesh. Click the toggle to the left of the selection mode buttons in your picture.


I start by making a few assumptions:

Your geometry is not too prominent.
It can get distorted quite a bit.

If these are true, you can use this trick.

There is one possible way. First you start by baking the height of the flat geometry. There are a number of ways to do this, see here for some possibilities:
How to make a displacement map from existing 3d geometry

Armed with the height map you model the Möbius strip. Unwrap it (hint: you only get one side). Then add a displacement modifier to it (you probably also want a "Subdivision Surface* below. Level four or five should do it.). Set the Displace to use the height map. Also set it to UV (messed this up myself a few times) and decrease it's strength. You can finish with the combo solidify-edge split-subsurf lv.2. For optimum results set the shading to smooth.

I hope this helps.


In order to reduce the size of the .blend file. Blender to a Maximum extent save only relative references. If you want to Shift your project to some other machine.You have to pack all the project files.

To save all the images to the .blend file Checkout File-> External data section


Everything works fine.

But you forgot to choose a UV for modifier approach

and used a wrong setup for shader displacement.

Also you'd better re-export your height map as OpenEXR or PNG 32 bit otherwise the result shall be jagged.

Your example file on developer.blender.org works fine too.


Unfortunately I believe you have started on the wrong foot.

You object has a very bad topology, it's not quad based, it is full of triangles. very unevenly subdivided with extremely high density on top contrasting with huge ngons on the sides, and unnecessarily subdivided in width direction.

All these things make harder to work with, Blender operators will misbehave, that is why you encounter these problems and are likely to expect further down the road.

Modelling applications generally like four sided faces, my advice is to start over with a better mesh base and work from there.

Watch some beginner tutorials on hard-edge modeling and follow these guides for topology


subsurface modifier, in short. Dont think this can be answered with a quick answer though. You'll need to work your way through numerous modeling videos either on youtube or the many great training videos DVDs that exist for blender.


VSE: Can you make a script to code in more filters? (add/multiply/subtract)

Turns out your build of Blender may be old.
They were updated as of this commit https://developer.blender.org/D2872
In fact there are a bunch of new blend types available.


Weight painting. Should this be happening?

The difference between weights happens when a vertex is assigned to at least two bones, because Blender normalizes the values: in your example every weight is compared with zero weight on any other bone, resulting in full strenght for every vertex.
If you create a new bone and assign her an equal weight to all the vertices, move only the first bone and you'll see the gradient expected.


Change the geometry of the ear to make the creases work. You may leave the edges of the mouth flow to the back of the head- it doesn't matter. The key here is to rearrange the edges flow in the way it creates a loop (see the example below).

Remember that you can always select the edges to crease then press the Shift+E to make them sharper.


How to use blender command lines in OSX?

Execute the following command in the terminal, then open a new terminal window and the blender command should work as expected:

echo "alias blender=/Applications/Blender/blender.app/Contents/MacOS/blender" >> ~/.profile

What this command does is add the following line to the end of /Users/SteveW/.profile:

alias blender=/Applications/Blender/blender.app/Contents/MacOS/blender

I strongly recommend to not mess with PATH or any other environment variable for this, it only makes things more complicated, there's no reason to do so when you set up the alias correctly.

On recent versions of macOS, .profile is not used. Use ~/.bash_profile  instead.

echo "alias blender=/Applications/Blender/blender.app/Contents/MacOS/blender" >> ~/.bash_profile


What programming languages can I use in Blender?

Since Blender 2.5 only Python 3 is supported. From blender.org:

  The Blender 2.5x versions feature a completely new Python API based on
  Python version 3.2, and is integrated deeply, used for generating
  Blender's GUI layouts, for import and export of external formats, and
  with access to all user-accessible data and functionality.

What changes across applications is the API - Application programming interface. So if you're used to pygame and console API, now you need to learn Blender API. So yes, the idea is the same, but the API is different.

Here's a Quickstart Introduction.
And here's the full API.


You can use Wireframe or Skin modifiers(note that you can adjust the radius per vertex in the n panel while in edit mode for skin modifier or with ctrl+a).

With Wireframe modifier you'll have to keep an eye on your mesh edges. Use N-gons wisely in order to pass the operator just the edges you need. For the provided example, a solution could be something like:

As you see the trick is to not build a complete mesh, but just the faces that hold the right edges. You'll also be able to assign different materials to the edges with vertex paint without having to apply the modifier.

You can also select only edges you want, invert selection with ctrl+i, delete everything else, select all and delete only faces (x menu) and then you are left with edges only. Then from object mode you can convert them to curves(alt+c) and then you can add thickness to them:

If you wish once you are happy with them you may convert them back to polygons with the same shortcut alt+c.


How do i add shapes and how do i get a Square?

this forum is happy to help with specifics, but not so much generic (or broad) ranging issues. I am relatively new to Blender and I found the following YouTube tutorial series valuable and these may help you:

Grant Abbitts complete beginners guide to Blender may be a good start (https://www.youtube.com/watch?v=7MRonzqYJgw). I have not done that one, but he has other beginner guides (https://www.youtube.com/playlist?list=PLn3ukorJv4vvWfYmRnGS260JTjhShJFRP) that I have done that are very good.
Blender Guru donut tutorial was interesting and fun and covers a lot of different aspects (https://www.youtube.com/watch?v=TPrnSACiTJ4)
Jayanam (https://www.youtube.com/channel/UCs5J4GVRB8s2P4hE-O0izrg) also does a lot of tutorials.

I was also fortunate enough to do CGBoosts Blender Launch Pad, which really took things from the basic approach, however this is not free.

When doing these tutorials and you get stuck or have a question, this forum will is a very good place to ask and will most likely resolve your questions.


There is an add-on for that called Motion Trail that allows you to edit the curves in 3D space. You can enable in the User Preferences under the Add-on tab.


Make sure that in the Global Transforms the segments have the same tilt:

When two segments have different tilt (90 and -90) you'll get a loop when you connect:

Wehn the segments have the same tilt, the segment will be straight:

If one of your segments is flipped try this:

Deselect all (A)

Select one control point and then select linked (L)

Rotate the whole segment 180 degrees by adding +180 on the Mean Tilt section.

Link it then with the other section.


Animating multiple Iterations of a single Oject along a Path?

Conveyer using a curve or path -

In "Ucurve.Blend", a vertical U-shaped curve-path was used to shape a conveyer belt/production line.

For a shaped path-curve the items couldn't be arrayed as would be usual for a straight conveyer.   An array following a curve would distort items on the belt at it's corners.  A path and 5 seperate items (cubes) were used instead.

A path can only have the one set of valuation-time keyframes meaning that multiple items would all be traversing the path piled on top of each other.

The solution used here was to have a duplicate but separate path for each of the 5 items and those placed in layers 1 to 5..  Each path had it's own valuation 0 & 1.0 evaluation frames offset by the delay between the first and next item appearing at it's start. (20 frames apart)  (See Dope sheet)

When played right through, for 5 items 20 frames apart, some 180 frames are necessary to accomodate all 5 items from the 1st's appearence at the start of the path, to the 5th reaching it's end.

In order to satisfy the need for a 'contiguous loop, the frame where the 5th item appears at the path's start is 81 so we loop the animation between frames 81 & 100. (19 frames in all)   --> Layers 1 to 5 selected.

This provides a looped animation in Blender but would be a trifle short for video so the 19 frames are output as H264 Lossless video.  This is imported into the VSE and the video strip duplicated and appended as many times as required.  The result, a smooth ongoing loop.

What's really happening is that the cubes (items) are moving only 19 frames forward then switching back to their start positions for another 19 frames and so on, giving the illusion they're advancing forward contiguously.

ADDENDUM: 13 April 2019

Because the path's end is also at the exit 'hole', the cubes stop at that location and just sit there.  Each cube is therefore 'switched off' with the  the Outliner's eye icon at the frame it reaches the path's end, plus 1.

The same is done at the path's starting point. Cubes are made invisible until
due to move.


By splitting and re-joining the faces, you're creating double edges.
That improves shading on sharp edges (since the edges are no longer continuous).

You can achieve the same by adding the Edge Split Modifier.

Or by selecting all vertices and using Edge > Split


NLA editor, I can't get two baked animations to work at the same time

In your NLA-Editor's properties panel (on the right); if you select your "movement" action, you can see the Blending mode. In the screenshot you provided it is set to Replace. Replace tells blender that any other tracks' keys on the same channel that are below it are overridden by the top track. You can set this to another type, for instance Add to add the location of the movement-action to the values in the idle-action.

A better way (in my opinion) would be to pay attention that the channels of your actions do not unnecessarily overlap. That means that your walk-cycle should not have keys for body-movement, and your movement-action has only keys for body-movement. If you have that you will have more flexibility in arranging the tracks later on. (In case that you design your walk-cycle by selecting all bones of your armature, and then do "insert key frame", then you will end up with a key in every possible channel, making it very hard to handle in the NLA-Editor. Better remove the unnecessary channel in the action editor then). For example, for a walk-cycle, i would only animate the up/down movements of an in-place walk cycle in one action, and make a different action for movement that effects only the x-direction of the root-bone of my armature, but nothing else.

Baking is mostly not needed for animations, as long as you have enough channels (and bones) to realize your animation. Sometimes, however, when a rig is too simple to support overlaying actions well, it might be necessary.


Limited dissolved over thousands of objects

To change the context object (for operators) use

context.scene.objects.active = obj

or new in 2.8, instead use

context.view_layer.objects.active = obj
# and select with
obj.select_set(state=True)

as well as (or instead of) setting the select property.

In your code above you would be running the op on context object for each object.

For multiple objects consider using the bmesh module as shown in this
Related Answer,  replace the remove doubles bmesh operator with limited dissolve.

Test code, runs the limited dissolve on every selected mesh object.

import bpy
import bmesh
from math import radians

context = bpy.context

distance = 0.0 # remove doubles tolerance.
if True: #def execute(self, context):

    meshes = set(o.data for o in context.selected_objects
                      if o.type == 'MESH')

    bm = bmesh.new()

    for m in meshes:
        bm.from_mesh(m)
        bmesh.ops.dissolve_limit(bm, angle_limit=radians(1.7), verts=bm.verts, edges=bm.edges)
        bm.to_mesh(m)
        m.update()
        bm.clear()

    bm.free()

On a side note, suggest using string formatting to make key names.

key = "Shape_IndexedFaceSet.%d_%d" % (hundreds, tens)
obj = scene.objects.get(key) # obj is None if not exist.

or with f-strings

key = f"Shape_IndexedFaceSet.{hundreds}_{tens}"


Shader Method
I used a Noise Texture with a Color Ramp set to Constant to generate a sugar sprinkle mask.

Then I mixed some noise into Generated Coordinates and separated out the Z axis.  I could then apply another Color Ramp to isolate the top of the cake.

Multiply these two masks together with a Math node and you get a mask that you can use as the Factor of a Mix Shader between your cake and sugar.  The top Color Ramp controls the size and density of spots of powdered sugar.

Particle System Method
Instead you could "model" a sugar particle by adding an icosphere.  Put it somewhere out of camera view.  Give it a suitable material for sugar.
Start a Particle System on your cake.  Set it to Hair and under Render select to Render As Object and set the Instance Object to your Icosphere.

Since we're emitting from faces you have to worry somewhat about an even distribution of faces on your object.  I didn't bother since this is just an example, and it might be useful to someone to see the consequences of it.
I've marked all the settings I changed to get this result.  (Note: Hair Length is the same thing as Normal Velocity.  In this case it is in effect a multiplier for your object scale.)

I thought maybe interpolated children would solve the problem automatically.  It does not, although it may make it easier to deal with in some cases and it provides an interesting result nonetheless.  Also beware that at default settings you'll generate 100x the number of particles on render.

If you want to limit to only a certain region, you can create a Vertex Group either through assignment or Weight Paint mode, and assign this as the Density group of the Particle System.


Game modelling how to get height details?

I am not too sure about Unity, but in blender the usual way to go from highpoly models to lowpoly models is to create a normal map from the highpoly and apply it to the lowpoly. To do this see here:
https://www.youtube.com/watch?v=BOYRCI-dtjU

Hope it helps :)


Mapping multipule textures to one object in blender

If you're going to use this in a mobile game, then it's best to place all the floor images onto a single texture.  UV unwrap the floor onto a single image and only have one texture (with the 3 different floor images on the single texture).

This way the game engine will only need to bind and sample a single texure (instead of 3) just to draw a simple floor.  I'm thinking of optimisation here, and if you can fit the 3 images onto a single texture, then that is the best way to go.


How do I load an mp4 video with multiple audio tracks into blender?

Blender does not currently support the importing of multiple audio tracks that are encoded into video containers. It will typically import the first track, though I'm not certain. I recommend that you use a program like Davinci Resolve which is free to use and is much better suited for video editing and has a faster viewport for video editing. I was once in a similar situation like you with multiple tracks of audio when using OBS.


Texture painting showing UVGrid when coloring

You might have set an UVgrid image as Brush texture.

The brush texture is color-multyplied by the brush color. If you remove the brush texture you'll be able to paint the color only.


How to check if an object has a particle system or other modifiers

The modifiers type are given here.

And you can simply test the type you want from that (including 'PARTICLE_SYSTEM' or 'COLLISION').

Here, they are simply printed:

import bpy

obj = bpy.context.object

for modifier in obj.modifiers:
    print( modifier.type )


Yes, the different UVMaps can be selected by an attribute node and plugged into the vector input of an image texture node as well as into another image texture node vector input holding an alpha mask of the image referenced from the first texture node. This way multiple textures (and UVMaps) can be mixed for a single material output.

This technique is demonstrated in this tutorial.


Is it possible to setup eyelashes with uv texture without using shaders nor hair particle?

If you have a .jpg/.jpeg texture for lashes/hair, set the material's specular-intensity value & transparency alpha value to 0 to show lashes correctly in Blender. The problem of this is that it will look fine in Blender, but if you export to .gltf/.glb file, the lashes/hair will be invisible.

So the only solution I found so far is to use a normal material but with a .PNG texture that has background removed. A little Photoshop work.


How to efficiently convert a PIL Image to bpy.types.Image?

Thanks for @batFINGER's reference to CodeManX's snippet this is the fastest option I got:
def pil_to_image(pil_image, name='NewImage'):
    '''
    PIL image pixels is 2D array of byte tuple (when mode is 'RGB', 'RGBA') or byte (when mode is 'L')
    bpy image pixels is flat array of normalized values in RGBA order
    '''
    now = time.time()
    # setup PIL image conversion
    width = pil_image.width
    height = pil_image.height
    byte_to_normalized = 1.0 / 255.0
    # create new image
    bpy_image = bpy.data.images.new(name, width=width, height=height)

    # convert Image 'L' to 'RGBA', normalize then flatten
    bpy_image.pixels[:] = (np.asarray(pil_image.convert('RGBA'),dtype=np.float32) * byte_to_normalized).ravel()

    print("pil_to_image completed in",time.time() - now,"s")
    return bpy_image

it was interesting to see that
bpy_image.pixels[:] = (np.asarray(pil_image.convert('RGBA'),dtype=np.float32) * byte_to_normalized).ravel()

was faster than
bpy_image.pixels = (np.asarray(pil_image.convert('RGBA'),dtype=np.float32) * byte_to_normalized).ravel()


I have this black line that can't be pressed on and not connected to anything, and I don't know how to remove it

Press TAB to exit from Edit Mode to Object Mode. click on the line to select the object containing it. Press TAB again to edit the mesh. Make sure the Edge Select mode is enabled:  - now click on the edge, press X (or DEL) for deletion and choose "Edges".


Ok. I finally got the depth data by directly connecting the z data to the viewer node:

# create input render layer node
rl = tree.nodes.new('CompositorNodeRLayers')

# create output node
v = tree.nodes.new('CompositorNodeViewer')
v.use_alpha = False

# Links
links.new(rl.outputs['Z'], v.inputs[0]) # link Z to output

# render
bpy.ops.render.render()

And then I output the information into an npz file to be used within python

# get viewer pixels
pixels = bpy.data.images['Viewer Node'].pixels
print(len(pixels)) # size is always width * height * 4 (rgba)

# copy buffer to numpy array for faster manipulation
arr = np.array(pixels[:])
fname2 = "depth.npz"
with open(fname2, "wb") as f:
    np.savez(f, arr)


Transfer Python code from Blender Render to Blender Game Engine

In the logic bricks you can add python scripts under "Controllers".  You would need to set a sensor "Property" or two that holds something to indicate the start/end of the game.  Likewise you will need to set that "Property" at specific times to achieve what you want.  "Restsrt Game" is under Actuators.

You may have to modify your code but you can do a majority with Logic bricks and sensing "Properties".  You can do something similar with changing cameras at certain times.

For detecting frames, just have your script set a Logic Brick property each frame change, you will need to keep an eye on your FPS as large scripts can slow you down.


How to scale two objects to fit together

Assuming nothing is centered or aligned (but rotation is consistent), use Snapping >> Vertex >> Active.

1.) Select a bottom vertex with which to align the half-sphere. L to select connected vertices.

2.) Drag it over to snap it to its "sister" vertex.

3.) Reselect the vertex and Shift + S to move Cursor to Selected.  Change the Pivot Point to 3D Cursor.

4.) Now, select the opposite vertex (make active) and L to select connected vertices.

5.) Scale to "sister" vertex.


Strange geometry when creating a face from points

I suppose you've given a Subdivision Surface modifier to your objects.

Subdivision Surface divides each edge with a new vertex, then join these new vertices in order to divide each face.

Here you have only one face, so all the new vertices will join at the center of this face. But giving your geometry this will happen out of the shape and this will give outer faces.

To avoid that you need to create some inner edges, like that:


Ok, I found one weird way:

I can split the bottom area vertically as well and then align the split borders of the top and bottom area pairs:

This alignment is easily possible because the split borders snap to a grid.

As soon as they are aligned, the context menu of the border between any top and bottom area gets a new item "Join areas":

After joining the left pair and the right pair, the bottom area is then gone.


Blender - Set blending mode(Porter-Duff) for a material

The Blend Mode in the material settings is only available when Render is set the to Blender Game:

For textures there are Blend types which are also available in the internal renderer.

I'm not sure whether you can map these properties to the required operators defined by Porter-Duff, thus custom properties could be a good alternative.


With adaptive sampling Cycles automatically reduces the number of samples in areas that have little noise, for faster rendering and more even noise distribution.
More info here: https://docs.blender.org/manual/en/latest/render/cycles/render_settings/sampling.html


file browser : how to always turn on the display thumbnail?

Info Editor -->File --> User Preferences --> File  --> Show Thumbnails

Then Save User Settings


Animation of several objects depend on main object

It is possible to parent multiple objects to the same armature. Simply repeat whichever method you used to parent the human to the rig on the clothing.

For example: Select the clothing and then shift select the rig and press "Ctrl + P" and then select "Armature Deform with Automatic Weights".


Blender Internal:
You can exclude a pass from the Combined pass by toggling the camera icon next to the appropriate pass in Render Layers > Passes:

Cycles:
The trick with cycles is that there is direct lighting and indirect lighting.
If you only want to filter out shadows, then it's as simple as dividing render by the Shadow pass with a Mix node. However, indirect lighting gets in the way of this. If you combine the Indirect pass with the Shadow pass, then use that to divide, you will remove all the indirect lighting and shadows. (you end up with a Color pass that has no shading at all).
here are some workarounds:
Renderlayers:
There might be a better way to do this, but you can use two renderlayers:
Layer 1 contains the cube object.
Layer 2 has the lights, floor and background.
Settings for Renderlayer1:
For this render layer all scene layers are enabled to render the object and background.

Settings for Renderlayer2:
For the no shadows layer, the scene layer with the cube is excluded and masked to remove shadows cast by the cube and to create a mask to combine with the other layer later.

Composite nodes:
All that remains to be done is combining the cube into the no shadows layer.
If you have Render settings > Film > Transparent enabled you could use an Alpha over node, or you could use a Mix node with the Alpha of the no shadows layer as a mix factor:

Material nodes:
You can filter out shadows per material with material nodes, e.g. for a shadowless and bounceless diffuse shader:

This will let light through the object when it's bounced indirectly of a diffuse object and when sent directly from a light source:

The obvious downside to this is you have to use two scenes and recreate your materials to use this for compositing.
Object shadow property:
You can also remove shadows per object by unchecking the Shadow box in the Properties Editor > Object > Ray Visibility:

To do this for all objects for use in compositing, you could

Create a new scene from your current scene.

A> select all

After disabling the Shadow box in Object > Ray Visibility, right click it and select Copy to selected to set this for all selected objects.

This will prevent all objects from casting shadows.
You can now use this scene in the compositor as a renderlayer.


Constraints may suit. The copy Xform constraints have the option to invert.

Here we have 2 axis-Empties, both parented to the cube-Empty in the middle. The right Empty is constrained to the left Empty as follows:

And it's parented to the cube Empty Without Inverse.

The arrows are parented to their respective axis-Empties, for illustration:

If the Empties are all ShiftD duplicated together, Blender is smart enough to keep the relations between the duplicates, and the whole rig can be moved/rotated using the cube.


I have attached a scene for your reference.

Basically, the scene is straightforward.
A text "G" with reflective and emission material & a wall with white material. Make sure you turn off ambient occlusion in your World Tab as it will throw false lighting in the scene. The wall material is almost completely white, due to the lack of light in the rest of the scene only the backlight is visible.

Hope this helps and is what you are looking for.


Having problems with add-ons: missing add-ons and incorrect warnings?

The reason it doesn't show up is that the "Add Curve" part of the name of the addon is simply the category in which it is located. If you search the rest of the name "Extra Objects" it will show up.

As far as I know, the warnings for needing other settings show up whether they are necessary or not. Not necessarily a bug, but it could be improved in the future to disappear if everything is in order.


Get and Set Hide in viewport and Disable in viewport via Python API

bpy.context.active_object.hide_viewport = True for MONITOR icon
bpy.context.active_object.hide_set(True) for EYE icon
for collections it's bit different
bpy.context.collection.hide_viewport = True will globally hide collection(MONITOR icon)
bpy.context.view_layer.layer_collection.children.get('Your_Collection_Name').hide_viewport = True wil hide collectiob locally (EYE icon)


Trying to get depth-information in Workbench

Im afraid it's not possible without modifications. As  stated in the manual, the workbench purpose is to provide a fast visual output for animators.

The Workbench Engine is a render engine optimized for fast rendering during modeling and animation preview. It is not intended to be a render engine that will render final images for a project. Its primary task is to display a scene in the 3D Viewport when it is being worked on.

The only options you have is to use the regular viewport color, metallic and roughness value or any of the display methods to show random, object or vertex color . Since those can not be filled with a map (to be used with a view dependent gradient to simulate a z-pass) you have not much options.
The only rough approximation possible, would be to use vertex paint, paint the distance into a gradient and render this in workbench, with vertex paint mode on.
But that is dependent on mesh density and also not dynamic.
You can however define a render in cycles or eevee, without any lights or shaders evaluated and just render the depth, this should be very fast, and deliver the result you are looking for !


Wacom Intuos Pro (tablet) not working with Blender on OSX

The solution is: go to System Preferences > Security & Privacy > Privacy > check "WacomTabletDriver".


Override the operator

I'm not sure how a  pre delete handler or event would work?.  Whenever I model, a delete could be coming  at any time lol.

However can override any operator with another.

If another operator (or panel for that matter) is registered with the same bl_idname, then it will override the one defined previously. Giving it the same properties as the original will see existing key-maps and UI use the new one seamlessly.

For some operators and panels where the python code is available can import them and use their methods in our own. AFAIK Not the case with bpy.ops.object.delete

To override the object delete operator (very basically) run the following script

import bpy
from bpy.props import BoolProperty

class OBJECT_OT_delete(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.delete"
    bl_label = "Delete Objects Override"
    use_global : BoolProperty()
    @classmethod
    def poll(cls, context):
        return context.active_object is not None

    def execute(self, context):
        print("do something here")
        for o in context.selected_objects:
            bpy.data.objects.remove(o, do_unlink=True)

        return {'FINISHED'}
    def invoke(self, context, event):
        return context.window_manager.invoke_confirm(self, event)

def register():
    bpy.utils.register_class(OBJECT_OT_delete)

def unregister():
    bpy.utils.unregister_class(OBJECT_OT_delete)

if __name__ == "__main__":
    register()

and it will replace the delete operator. Is this good practice or recommended.. not sure (shrug) .. but it is one way to "do something before the delete operator is called"

Note: the prepend and append as shown in question is more associated with adding UI to a panels draw method.


While it's not the Dopesheet, but the Graph Editor, yes, there's a workaround to retime it. Animate the start frame of the build modifier.

So far the build modifier cannot easily be animated by percentage or face count (without using python). And the speed curve does not work with modifiers as of yet.

A workaround to achieve variable speed is as follows:

The build modifier is controlled by two values. Start and length. For this approach, length should be set to either 100.0 for easy calculation or to the facecount, if desired.

The trick is to animate the start value in respect to the current frame. Here are the rules: The modifier is stopping it's progress if you animate the start frame in parallel to the frame number. Start frame 50 in frame 50, start frame 90 in frame 90 (don't forget to set the IPO curve (sorry, I mean F-Curve) to linear or you won't be synchronous due to the ease in and ease out nature of the beziers).

The build modifier progresses forward if the start value rises slower than the frame number:
length 100,
start frame 50 at frame 50
start frame 100 at frame 150 (offset of 50)

will make the build modifier progress at half speed until the 50% mark and then progress at full speed, if nothing else is animated.

Whenever the start value is identical to the frame number, the modifier is at 0.0 per cent.

So the formula with which to calculate animation values is:

start value = frame number - (length / 100 * percentage)

You find the values in properties>>modifiers>>build modifier panel

Look at it a little bit like two cars, one moving at constant speed (frame number) and another catching up or falling behind (start value of the build modifier). The distance between the two cars defines the amount of built faces.


How do i set a object with particles to the background and keep another object in front in composition?

Assuming your rendered image has an Alpha channel then simply change the last Add node in the chain to ‘Mix’ and use the Alpha as the Fac. This will mix between your shapceship and the stars based on the alpha.

Note that if you don’t have an alpha (if you haven’t rendered with transparancy enabled) then you can use the Depth as a filter instead as it will be very high for points on the background behind your spaceship (1000000000 or similar - effectively ‘infinity’) and much lower for points on it - pass the Depth through a Greater Than maths node to compare it with, say, 10000000 and the output of that can be used effectively as an alpha.

This resulted in a final solution (from @IvanVujacic) as follows :


The vertices you selected can only be selected when you press Alt+Click so your might be accidently pressing Alt while selecting the vertices. To select multiple vertices, you need to select one vertex, press and hold Shift, select next vertex, and so on.


How do I get blender to stop creating so many files?

Any file with ".blend" and then a number is a backup file created by blender. This is not related to Save or Save As, which act the same as other program's implementations of them. Every time you save, the previous saved version gets loaded into ".blend1", so these extra files are your previous saves. If you ever wanted to use one of these previous saves you would rename the extension back to ".blend" and open it.

You can go to File> User Preferences> File and set Save Versions to 0 if you don't want these extra backup files:


Reset rotation direction of mirrored object

Ok, so we have a scene with a pair of mirrored objects. I am using arrows because they have a clearer direction than spheres.

Supposing that they are created with a mirror modifier, you will have something like this in your modifiers panel:

Now, if you rotate the eyes in edit mode, you get this:

To spin the eyes differently, you will have to separate them from each other. This is a destructive operation.

(Personally, I would first back them up to another layer. To do that, duplicate (Shift + D), then cancel the grab (right click). Then move the copied object to another layer with m.)

Apply the mirror modifier by hitting apply here:

Then, in edit mode (Tab) hit P and select By loose parts. Now you have two objects, but their centers are off:

Select one of the eyes and hit Ctrl + Shift + Alt + C and select Origin to Geometry.

Now you can happily rotate the eyes independently. To make the eyes move in synch, go to constraints:

There, Add Object Constraint > Copy Rotation (second row, second collumn). Then pick the other eye as Target:

Now the objects rotate in synch:

You can also make it so that the eyes look at a point in space. First, add an empty to be that point (Shift + A > Empty > pick any you want.) Put it where the eyes look. With one eye selected go in Constraints and add Track To. Select the empty as the Target. If the eye points the wrong way, play around with the To: and Up: parameters until it works. Repeat for the other eye. Here is the result:

I hope this helps.


Making a hole in a Dynatopo sculpt without Boolean

You can try to use a more advanced boolean solver. there's a plugin somewhere that uses the CarveMT solver to make more complex cuts

The biggest villain in boolean operations is that it comes to a point blender doesn't know how to deal with all the vertices and all the new geometry it has to create to accomodate the change, be it a union or a cut. If possible, decimating or reducing the mesh density in the area of the cut will increase the chances of success


how to make a limit for the loop cut tool

Switch to Face Select Mode, select the faces you want to keep and hide them with H. Then do your loop cut. After that, reveal your faces with ALTH.

The loopcut will have added a new vertex but it will not have cut through. So, if you have hidden some quads, you will get an ngon. Not ideal but you can retopologize it later.


UPDATE
This answer is obsolete, blender has now this functionality
This little script lets you duplicate a view layer with its visibility settings only, render passes and cycles settings, render and selectable are settings that are shared among all layers.
import bpy
context = bpy.context
old_layer = context.window.view_layer
new_layer = context.scene.view_layers.new(old_layer.name)
collection = old_layer.layer_collection
new_collection = new_layer.layer_collection

for prop in dir(new_layer):
    try:
        attr = getattr(old_layer,prop)
        setattr(new_layer, prop, attr)
    except:
        pass

cycles = old_layer.cycles
new_cycles = new_layer.cycles
for prop in dir(new_cycles):
    try:
        attr = getattr(cycles,prop)
        setattr(new_cycles, prop, attr)
    except:
        pass

def recursive_attributes(collection, new_collection):
    new_collection.exclude = collection.exclude
    new_collection.holdout = collection.holdout
    new_collection.indirect_only = collection.indirect_only
    new_collection.hide_viewport = collection.hide_viewport

    for i, _ in enumerate(new_collection.children):
        old_child = collection.children[i]
        new_child = new_collection.children[i]
        recursive_attributes(old_child, new_child)

    for i, _ in enumerate(new_collection.collection.objects):
        tmp = collection.collection.objects[i].hide_get()
        new_collection.collection.objects[i].hide_set(tmp)

    return 0

recursive_attributes(collection, new_collection)
context.window.view_layer = new_layer


How to read excel file and use as coordinates in python code?

Alternatively, you could use the pandas library. (How to install - see here: Using 3rd party Python modules)

With pandas, you can then use the pandas.read_excel() to import your worksheet into a DataFrame, which is basically an array but with named columns to make indexing easier.


propagate a predefined python surface over time

Here is the blend file with the modified script. Basically, you have to:

create a few shape keys, with incremented angle given to sin function
uncheck the Relative box for basis shapekey
make the interpolation type linear
set the value of evaluation time for the end frame one less than the maximum evaluation time


Blender 2.8 Material colors bleeding through faces in render

From what I can see from the screenshot, it looks like you've duplicated the faces and left them in the same place as the source face you duplicated it from.

This will cause problems because the renderer wont know which one is on top of the other - and so you end up with all those jaggy artefacts where it's kind of struggling with which one should be rendered over the other.

Quick solve to that is to just move the black faces out - can be by the smallest amount, just so they don't occupy exactly the same coordinates.

But, if the aim was to make those faces black, then duplicating the faces on top isn't the best method.

So I presume you have that mesh with one 'red' material ye?
Add a new material slot, create a black material in that, then go to edit mode of the mesh (if it's all one mesh) and select the face you want black, then 'assign' the black material to that face. (obviously get rid of your duplicate faces too)

If that's not the case, and the mesh just has duplicate faces, then you need to do some cleaning and remove the duplicate faces, merge vertices etc.


I think the problem here is that the light setup in Blender differs from the light setup in g3dviewer.

If you view your mesh in Solid display mode, Blender uses three directional (sun) lamps to illuminate the objects. You can find the settings of these lamps in the system tab of the user preferences:

The direction of these lamps is relative to your current view, so if you rotate your view around in the scene the lamps will rotate with you. This ensures a good illumination of all objects.

If you are in g3dviewer you have to replicate the light setup to get the same results.

If you are still in doubt about the exportet material have a look at the .mtl file that is written with the .obj. It contains the materials of the meshes.

Take this simple red material for example:

In the .mtl file it looks like this:

newmtl Material
Ns 96.078431
Ka 0.000000 0.000000 0.000000
Kd 0.640000 0.000000 0.000000
Ks 0.500000 0.500000 0.500000
Ni 1.000000
d 1.000000
illum 2

The line starting with Ns contains the specular exponent of the material. In Blender the range of the specular exponent (called Hardness here) is 0 to 511, while in .mtl the range is 0 to 1000. Exept for a rounding error '96/1000' is equal to '50/511'. This is how the specular exponent gets translated.

The next line Ka contains the ambient color. Blender does not have per-object ambient color. You can find the ambient color for all objects in the world settings. It is set to black by default, thus the red, green and blue component of the ambient color are zero.

The third line gets more interesting: Kd describes the diffuse color. But while in Blender you can set the color value and the intensity separately, they are multiplied in the .mtl file. If you have a look at the screenshot, the red value of the color and the intensity value both are 0.8. Thus the red value in the .mtl file is 0.8*0.8 = 0.64. Green and blue are 0 in blender, so they are also zero in the .mtl file.

Next is the specular color Ks. It works similarly to the diffuse color. The specular color in blender is white (1.0 in all channels) and the specular intensity in Blender is 0.5, so the resulting color in the .mtl file is 0.5 for red, green and blue.

The value Ni is the so-called 'Index of refraction' (IOR). It is set in the transparency settings of the Blender material and describes how strongly light is bent when it passes through the boundary between transparent materials (i.e. air and glass). Since I have not touched the transparency it contains the default value of 1.0.

d is short for dissolve. This value is called Alpha in Blender and represents the opacity of the object. A value of 1.0 means that the object is completely opaque, a value of 0.0 would mean that it is completely transparent.

The number after illum encodes the illumination model used for the current material. You can find a list of all illumination models and their corresponding numbers in the link at the end of my answer.

With this information you should be able to verify if Blender exports your materials correctly.

You can find a complete description of the .mtl format here.


particles(fur) doesn't update that fast try alt-a or a quick render it should be fine


The frame renders just fine, it just takes a very, very, very long time to synchronize the objects... You are using a highly subdivided model. In my opinion you don't need that many vertices.

Try simplifying the topology and reduce the number of vertices as much as you can.

Additionally, instead of animating the visibility of the objects, play with shapekeys, so that you are dealing with a constant number of vertices for the start and end of the morph transformation.


Trying to exact copy object "A" location on "x" axis with object "B" following a curve. Both objects need to have matching "x" #'s

If you convert the curve into a mesh, then add the shrinkwrap modifier to the cone to follow the mesh, AND add a driver to the x axis of the cone to copy the x axis of "var" (which is the x axis location of Suzanne). The copy location modifier on the cone will not work.


Make sure the limit method on the bevel modifier is set to angle, so that only the edges between faces with very different normals are beveled:

If you have the limit method set to none, the edges on the flat parts of the cube will be beveled (which creates extra geometry without changing the shape), and the UVs are not interpolated correctly:


3d objects that disappear in my scene when rendering using cycles

Following is the answer to the problem i had:
after conversing with @lemon , he/she as found a the answer.
Regarding the modifiers i was appliying, the subdivision surface modifier was set to 0 for the render as you can see in the image.

So, the smooth modifier was smothing a mesh that has to few vertices to be seen on screen.


How to import FBX file with texture map?

Ok. So the answer is - included with your model are texture maps for 2 separate materials: one for the lid, and one for the back wall. I had to add a new material slot to one of them (maybe both, I can't remember) and hook up the texture maps through those, but the UV's are fine. There is both a reflection map and a glossy included as part of the texture pack, however, they are both the same image so I used one for a roughness map, and I'm not sure if the other one is supposed to be metallic, because I don't know what the final product is supposed to look like, so I omitted it.
Anyway, I connected the textures by the number in the name of their respected object (the only ones that apply to your materials end in 02 and 04), through the node setup in the image below. Note that the color space for the roughness and the normal maps is set to non-color - this is important. Have a look:

I have a copy of the .blend file with everything connected. Let me know if you'd like to have it, and i'll send you the link.


How can I add auto weight to a new object and use the animation from other object?

I'm assuming this model is rigged, so parent the new object to the model, with empty groups. go to the vertex groups, and select the bone you want it to be parented to. go into edit mode, select the vertices you want animated, and assign them to the correct bone.


Error ImportError: No module named 'bpy'


Try the select Interior Faces Command and see how close it gets you.


How to access the list of volume grids using python?

Recommend use the python console to figure out the path, especially for new and undocumented properties. ObjectData.grids collection holds all the data (fields) you're searching for:

>>> C.object.data.grids.items()
[(0, bpy.data.volumes['Object_Name']...VolumeGrid),
 (1, bpy.data.volumes['Object_Name']...VolumeGrid),
 (2, bpy.data.volumes['Object_Name']...VolumeGrid),
 ...

To get the name for each field, use a for-loop:

>>> for field in C.object.data.grids:
...    print (field.name)
...
density
fuel
heat
temperature
vel.x
vel.y
vel.z

Or a list comprehension to collect the names for your shader setup:

>>> [field.name for field in C.object.data.grids]
['density', 'fuel', 'heat', 'temperature', 'vel.x', 'vel.y', 'vel_z']

Example script on how to check whether there is a certain field (density, fuel, heat etc.):

import bpy

C = bpy.context

for field in C.object.data.grids:
    if field.name == "density":
        print ("Got density")
    else:
        print ("No density field")


Just add more loopcuts to have enough verts and then connect a circle.

Add more loopcuts and make a hole in the mesh
Position the 3D cursor there (Mesh > Snap > Cursor to selected)
Add a circle with proper number of verts and connect it


Sometimes, maybe. The script below will set the count of ALL the particle systems in the scene except those that have been manually edited. I looked for a way to set the value of only selected objects (bpy.context.selected_objects) but couldn't find a way to access the count from there.
import bpy
D = bpy.data

for particle in D.particles:
    particle.count = 1000


How to apply the multiply effect strip on more than 2 video clips?

There are several ways to do what you want.
The first option is not to use an effect strip at all an just set the blend mode of the two top strips to multiply..

If you must use an effect strip then select the two strips at the bottom, add the effect strip, and then select the effect strip and the top strip and add a new effect strip

A third way is to add the effect to the two top strips and then create a meta-strip, and then add a new effect to the bottom layer and the meta-strip.

From the Wiki

A Meta Strip is a strip which contain several strips. It's like a Group of strips, working the similar way as Nodes groups. It allows you to reduce significantly the (vertical) space used in the sequencer, and treat multiple strips as if it was one strip. You can move, resize, and edit properties exactly the same way strips are. (see Editing and deleting strips page for more informations.)
You can edit the content of a Meta Strip by pressing ⇆ Tab; It will unwrap the content temporarily and hide any other strips present on the workspace, allowing you to select, move and resize the contained strips, or edit their properties. Press ⇆ Tab again to re-wrap the strips into one Meta Strip.


How to wrap multiple 3D objects around a UV sphere?

From what I can understand you want your 3D mesh object to "wrap" around the sphere. I think the shrinkwrap modifier can help.


How to interpret Blenders python tips when hovering

The command you want is:
bpy.context.scene.world.node_tree.nodes["Background"].inputs["Color"].default_value

This will access the background color of the world in the current scene.

Your command doesn't work, because you're not in the right context. If you're in the scripting workspace and take a look at the bottom left window, you'll see that before bpy.data.node_groups["Shader Nodetree"].nodes["Background"].inputs[0].default_value = (0, 0, 0, 1) is bpy.context.space_data.context = 'WORLD'. In the wrong context it's entirely unclear which node tree you're trying to access. That being said, I don't know why the command in printed as it is, because even in the color picker it would rely on the context passed to the panel and not access data like this (because it wouldn't work either).

The Blender Python API docs are always helpful, as well as CTRL+SPACE in the Python console for possible options.


Parenting bones and armature: " cant find solution for one or more bones"

The automatic weights option works only if the mesh is single and manifold (no spare parts, no holes, no doubles, no intersecting areas, no loose geometry).
Search in this site with keywords "bone heating" for more informations, or do a manual weighting if you can't fix the problem.


Render specific layers with python scripts in BGE

The game engine has no concept of layers beyond the active one and all the inactive ones.
So the simplest solution is to put the levels on different scenes and use the set-scene actuator.


How can I realize "sticky" collision, i.e. that objects connect as soon as they touch?

Try the free molecular script Add-on. here is a tutorial on how to use it:
https://www.youtube.com/watch?v=haS3B6q82kY


Is there a way to assign materials based on a color map in blender?

You may be able to use mix shader nodes

I achieved this result;

Using this node setup;

And these black and white textures (painted in blender, directly on the object);

.blend file here;

Effectively, what this does is uses the black (0) and white (1) or gray (some decimal value in between) as a factor for a mix shader. This mixing can be added to as many times as you like with this setup.


How to fix 'Modifier is disabled, skipping apply' error?

Without proper settings a modifier is "disabled" as it can't perform it's task. To enable a modifier, suitable options need to be chosen - for the armature modifier that is assigning an armature to it.

Given that the modifier is not doing anything you could also delete it without effect.


You can copy the modifiers from the active object to the selected objects with ⎈ CtrlL> Modifiers, or you can join all the cylinders into one object with ⎈ CtrlJ.

In this case I would probably join them.


Is there a shortcut to hide everything else except the object that's selected?

Press / on the numpad for Local View.

Press it again to go back and toggle it off.


Move one object and second object on the circle path will stay in nearest distance to first object

Circle path
You can give your object Copy Location constraint with Empty as a Target and Limit Distance constraint from another Empty with Distance as the radius of you circle. Copy Location tries to move the object to the location of your empty but Limit Distance wont let it. Now you can move another empty as you wish and the object tries to get it but will stay with the circle. Also Limit Distance Clamp Region needs to be On Surface.
You don't need the circle. Just your object and two empties.

Square/Rectangle path
To make to object follow a square or a rectangle you still need your object and two empties. First you have to Copy Location of the empty you want to follow. Next give your object a Limit Distance constraint with Clamp Region Outside a Distance that is greater then the farthest point of your rectangle. Last give your object a Limit Location constraint with minimum Minimum x and y and Maximum x and y that give you the size of your rectangle¨.


I would do it that way :

First, create your cylinder by using an elongated rectangle. Delete the bottom face.

Add a subdivision surface modifier. Don't forget to smooth it out with Object > Smooth

Add an array modifier to get your row of 3

This is the trickiest part. Add an empty in your scene. Add an array modifier with a constant offset and set the empty as an object offset :

Drive the empty rotation depending on the array count :

Add a displacement modifier, add a new texture and set the direction to "RGB to XYZ".

In the texture tab, set the type to "Clouds" and the color to "Color". Increase the size. There is a soft limit of 2 but you can manually input higher values.

Tweak the displacement modifier strength so that it is believable.

Result :

If you want lower frenquency in your displacement noise, you can add another displacement modifier with a new texture, set to a higher size.

I didn't go full non-destructive but you can still tweak some parameters :

Addition (Thanks R. Betts :) ) :
To give a nicer transition between the base of the cylindrical thingies and the plate, I modified the base mesh to have a square extended base :

Next add a vertex group, and make sur only the top vertices have a weight of 1.

In your displacement modifiers, make sure the group is selected so that the base doesn't get displaced :

Final result (Eevee - By no means supposed to look realistic :) ):

The blend file :


I am not sure this will help, but make sure in weight paint mode, the side of the neck that is not moving is not blue. If it is blue it will not be affected by the bone so you can then weight paint onto it and make it affected by the bone. I hope this help!


Lost one of my tool bars in blender and can't get it back

My screen recording is a little messed up, but I am clicking and dragging the little triangle tab in the top right of the 3D Viewport to the left, then clicking and dragging the new triangle downward.

Set each of these new screen areas to the desired UI screen type.


I had the exact same problem. I had to remap my texture on all the shards. I did use project from view to unwrap, which should be fairly painless for you if you've just got that cube.


You don't have enough resolution on your mesh to go with or you have bad setting of dyntopo that generates less resolution than before.

first things first, apply scale before sculpting by ctrl + A > scale

then we have many methods of sculpting in 2.79 including: sculpting with multires modifier, sculpting with Dyntopo

some of the ways you can use Dyntopo are using relative detail or constant detail.

when on relative detail, having a small number on it and zooming in gives you more detail.

when on constant detail having a larger number gives you more detail. one of the downsides of Dyntopo is that it can be heavy to work with so it's good to just use detail flood fill option and disable Dyntopo. note that Detail flood fill does not work on relative detail option of dyntopo.


How to get vertex back to its original position?

If its only moved on the y-axis... you could press "n" to get the properties window on the right side... and copy the y-position of another vertice in the ring to that vertice.


A will select all geometry.
⎈ CtrlL will select all geometry that is connected to your current selection.
For example, from this state in edit mode:

Pressing A will result in this:

Pressing ⎈ CtrlL will result in this:


Is it possible to use a frames marker name and append it to the file name upon export?

No, this isn't supported, however there are some options you could try instead.

Stamp the marker name into the file and read the marker name back out later. (JPEG, EXR, PNG support writing stamp data into the file)
Write a pre-render handler to impliment this with a python script, so before rendering, change the name based on the marker (I didn't check this works, only some settings can be changed while rendering). (See: http://www.blender.org/documentation/blender_python_api_2_71_release/bpy.app.handlers.html)
Render marker ranges - See: https://blender.stackexchange.com/a/15373/55 triggered by a python script.


What is the meaning of the strength of the sun lamp?

This is in the documentation:

  Strength of the lights in Watts per square meter.

Though, I'm wondering if that should be kilowatts instead of watts.


Why is my render all blurry and pixelated?

Your video output looks so bad because of the low quality setting specified in the render output.

First Things first:

You should never render out your 3d renders as movie files, NEVER! The reasons for this are:

If you mess up the quality settings you will have to re-render from the beginning
If you computer crashes halfway through the rendering all render will be lost and you will have to start over

The only time when you would want to render out a movie in blender is when you have an ready rendered animation as an image sequence and you want to convert it to a single movie.

The proper way:

Render out your animation as an image sequence. The output files should be a very high quality image which is why I would use either: png, tga, exr or whatever will yield a good looking image
In the blender Video Editor load the image sequence as an image sequence.
Now render out as a movie

Back to the actual question. You need to increase your render settings. Here are the important parameters you need to consider increasing:

Format

Bitrate: The target amount of data per second in your video file
GOP: The number of key frames for the color palette. A value of 10 means that during those 10 frames all are drawing frames based on the same 256 colors. If your scene is changing color during this time the quality will suffer.

Rate

Minimum: The lowest the Bitrate can be per second
Maximum: The highest the Bitrate can be per second

I think in your case the following settings would yield satisfactory results


You just need to add another Mix Shader node mixing the output of the first Mix Shader node with another transparency shader. Then you can keyframe the Fac amount on the new Mix Shader node to fade out the object (or more precisely to fade out this material wherever it is applied to the object).

As an extra note, you may want to control the speed of the fade by editing the Fac value transition in the Graph editor.


How do I close the User Preferences window when it is not opened by the window manager?

You can open the preferences inside the existing blender window by setting the editor type in the header of any existing area:

As for why blender isn't getting a titlebar from the wm, I have no idea. It works fine for me here on openbox.


There are absolutely inconsistencies, I believe it's a result of smoothing but may be wrong. Mesh is absolutely perfect before using sculpt mode (I checked), from the side in this image you can see that the mesh no longer aligns correctly. This was using X symmetry, the default brush (+ autosmooth) + smooth / autosmooth.


Finally I found an answer.

I used Edit Mode > Face select > Mesh > Bisect.


It would be easier for You to use Shrinkwrap modifier on the lower poly mesh and make high poly mesh its target. This way no matter what you do, vertices will stick to high poly mesh surface. I usually also check "keep above the surface" option and make Offset something higher then 0, but it's not crucial.


How to import footage in the VSE for optimal playback and organization?

HOW TO IMPORT FOOTAGE IN BLENDER FOR OPTIMAL PLAYBACK AND ORGANIZATION
When you want to edit videos in Blender, always, always use the option in the startup pop up:

If you use the tab to create a new workspace, your colors will be set to Filmic, and your colors will come out wrong(looking flat)

The View Transform to use is standard:

In the Video Editor workspace, though the file area looks nice, you can only drag and drop one file at the time(and only insert snapped to the playhead), and all of the file type import options are missing, so let’s get rid of that, by pulling in the corner.

On the other side we have the project and render settings. All info we need is the resolution, aspect and fps. These settings needs to be the same as the footage we plan to import. If there is a mismatch between the source footage and the project settings, we’ll experience a drop in playback rate, and we don’t want that.

So before importing our source footage we’ll need to download, install and use MediaInfo: https://mediaarea.net/en/MediaInfo to detect the settings of our footage:

And then make sure that the Blender project settings matches the metadata of the source files. When this is done the Properties region can be removed by pulling the corner of the neighbour over the region(the render settings can be accessed from the tabs).

It is recommended to import a single clip of the source footage and test if the footage plays frame accurate or not, if it doesn’t the VSE offers options to use caching.
Cache:
In the sidebar the there is the Cache Settings, in the Preview sidebar there is the Prefetch Cache option and in the View menu there is the options to show the cached areas in the Sequencer region as an orange line and finally there are Cache to disk options in the System Preferences. All of these elements can be useful for working with lots of effects or if ex. your footage is caching faster than your footage is playing. This is not the case for me and I’ll have to switch all of these elements off(to avoid processing loss) and go for rendering proxies.

Using Proxies:
A proxy is a rendered file in an edit friendly codec and typically in a lower resolution, to ensure an improved playback frame rate. In 2.90 https://builder.blender.org/download/ there is this simple menu in the Preview:

If you got a lot of footage I would recommend you to import this footage into a new(use copy to preserve settings) scene called ”Footage”, your first scene I would rename to ”Master Edit”. It can be done in the project header:

Now import all of your footage into this scene, by using the Add menu(yes, I know, it is odd to ”add”, when it is file related), and select Movie(yes, I know, it is odd to call footage ”Movie” when it actually is video).

If you project fps to match the footage it will align up nicely like this or if there is a mismatch the audio will be above and below(undo and fix the mismatch before importing again):

Now select all strips. Shortcut key: A and go to the Proxy menu and select Setup.

I prefer to use 50% because 25% is at most resolutions terrible to look at. When I okay this, these settings will be applied to all selected strips. Now I go to the Proxy menu again and select Rebuild(yes, I know, why isn’t it called build?).

And then Blender will start rendering the proxy files one by one:

When it is finished I go to the Proxy menu again and select Render Scene Size and select 50%, so now the preview will show the rendered 50% proxy file instead of the original and heavy file, and hopefully the playback rate will now be solid.

Since we imported all of our footage into a scene called “Footage”, we can now copy the strips we need, switch to “Master Edit” and paste them at playhead position. We just have to remember also in the “Master Edit” scene to set the Proxy Render Size to 50% in order to also view the proxy files here.


Turntable rotation with Y-axis up add-on

space_view3d_turntable_y_up.py
Enable turntable rotation with Y axis up.
space_view3d_turntable_z_up.py
Enable turntable rotation with Z axis up.
space_view3d_turntable_any_up.py
Enable turntable rotation with any axis up, the axis that is the most vertically aligned is the up axis for the turntable rotation until a new mouse gesture, i.e. until either the mouse button or the keyboard key modiffier is released.

All addons have the keyboard combination by default to
Ctrl+Left Mouse Drag because there is no need to install them all.

Neither disables the built-in view rotation, so that one can have both the trackball (built-in) and the turntable (addon) at the same time mapping them to diferent keys.


How to align objects to the center of another object

The way to solve this is pretty simple: Select the objects you want to align, go to the "object" tab, and select "transform". This will give you another drop down menu, which at the bottom of is the option "Align objects". Select this, and a menu will appear on the left. It will show some options for aligning the selected objects. Play around with these settings until you have a pleasing result. You can also shift-click on the x,y,z align options to align on multiple axes at the same time.


Create non-animated, realistic film noise w/ scratches procedurally

You could do something like this.

The graph is comprised of mainly 2 parts - the "spots" and the "lines". Similar to what you were thinking, instead of Noise Textures, I used the distance output of Voronai Textures to make the "grain dots". I used varying levels of scale and randomness in addition to clamping the values with ColorRamps and using them to add a slight mustard-like hue (to match your image). I made 2 "fields" - one slightly dimmer than the other, and combined them using a Noise texture as a mix factor, so the end result would be a "patchy" combination of the two.

For the lines, I used a series of Wave Textures, offsetting some with Mapping Nodes and subtracting their values from each other, until I was left with some randomly spaced white lines that I then further darkened with another Noise Texture (so they aren't so evenly bright).

The last step, I used a Noise texture, heavily clamped to make the small white dots that are lightly "speckled"  around the image.

Finally I put them all together. I used an Emission Shader, as it makes sense that this is being emitted from a screen, and I ran the output through a HSV node first for finer control over the color and the brightness.

I'll post the file here, so you don't have to take the time to rebuild the graph yourself if you want to play with it.
File is here -


Texture after modeling is very light? Ambient occlusion with photoshop

Fixed it! I had to change the blend mode on both my AO layer and my UV layer to "Multiply" in photoshop. I had only changed my AO layer to multiply, but the UV layer needed it as well.


Sequencing Animations in Animation Nodes

Animation Nodes already provide such nesting functionality in the Animate nodes, and you can similarly implement an equivalent functionality if you choose not to use the native Animate nodes.

An Animate node interpolates between two values for a certain duration. For instance, if the start value was 0, the end value was 5, and the duration was 20, then the output will gradually increase from 0 based on the chosen interpolation for 20 frames where it reaches 5 at the 20th frame.

But what about the frame at which the animation starts, how do we define that? Well, Animation Nodes always starts the animation at frame zero. However, the frame/time is exposed as an input in the Animate node, so what we can do is edit this input frame/time such that it becomes zero at the frame we want the animation to start at. This is easily done by subtracting the target starting frame $f_t$ from the scene or master frame $f_m$, because when the master frame becomes equal to the target frame our equation returns zero  $f_m-f_t = 0$. This is what the Delay node does, it simply subtracts the input, nothing more, nothing less.

Now, the Animate node provides a Time output. This output is the input time minus the duration. Think about that for a second. It means that if the output time of an Animate node $A$ is used as the input time of another Animate node $B$, the $B$ animation will start as soon as the $A$ animation ends. Now, if I delay (by subtracting) the output time of the node $A$ by 5 frames and use it as the input time of the node $B$, then the $B$ animation will start after the $A$ animation ends by 5 frames. And so on.

So, to implement a sequence of animations, use a chain of Animate nodes where the input time of each node is the output time of the previous with a possible delay (With the first node having the master time as its input, also with a possible delay). Want to add an animation at the start of the sequence, no problem, just put this node first. So the node tree should look like this:


How to turn face from existing mesh into new mesh?

Step one: Give the Cube an Edge Split modifier and apply it. Now you have a mesh with 6 separate faces. If you have a mesh with less pronounced angles, you might need to select all faces and hit CTRLE 'Mark Sharp'.
Step two: Go into edit mode and hit P for seParate and choose 'By loose parts'.
Step three, optional: in object mode, select all the new objects and in the tools, use 'set origin to geometry'. All faces have the object origin moved into their middle. Depends on what you want to do.

I recommend saving before trying this with a mesh that has lots of faces. Separate can take quite some time and has no indicator whether it's still working.

P.S.: I scaled the object centers of the right Suzie's faces to illustrate the effect. If I hadn't, it would look identical to the left Suzie.

I eventually came up with a script. It uses the active object as its source.

import bpy

targetName = "new-object" # name for the new objects

def createNewObj(verts, faces):
    global targetName
    newMesh = bpy.data.meshes.new(targetName)
    newMesh.from_pydata(verts, [], faces)
    newMesh.update()

    obj = bpy.data.objects.new(targetName, newMesh)
    scene = bpy.context.scene
    scene.objects.link(obj)

def iterateFaces(sourceName):
    obj   = bpy.data.objects[sourceName]
    mesh  = obj.data
    verts = mesh.vertices
    faces = mesh.polygons
    total = len(faces)
    counter = 0

    for a in faces:
        newFace = [list(range(len(a.vertices)))]
        newVerts = []
        for b in a.vertices:
            newVerts.append(verts[b].co)
        createNewObj(newVerts, newFace)
        counter += 1
        if counter % 100 == 0:
            print(counter,"/", total, "done")
    if counter % 100 != 0:
        print(total,"/", total, "done")
    print("Separation finished.")

if bpy.context.active_object.type == 'MESH':
    sourceName = bpy.context.active_object.name
    iterateFaces(sourceName)
else:
    print("The selected object isn't a mesh")


Displace modifier using an Image Texture on a Grid Mesh

In the modifier you should use Texture Coordinates > UV in order to control how the picture will print on the surface. So beforehand you must select your plane, go in Edit mode, select all and unwrap with U > Unwrap. I've also tested with a Subdivision Surface modifier above and below the Displacement modifier, it looks like it works better (note that your picture is very pixelated though so it will never be perfect).


Blender selection in viewport suddenly slow

Slow selection is usually fixed by changing the Selection mode in the System panel of the user preferences.

From the manual page about troubleshooting slow selection:

OpenGL Occlusion Queries (User Preferences)
See User Preferences ‣ System ‣ Selection.
This option defaults Automatic, try setting this to OpenGL Occlusion Queries, since there is a significant performance difference under some configurations.


How do i change encoding settings with python

Try this:

import bpy
for scene in bpy.data.scenes:
    scene.render.image_settings.file_format = 'H264'
    scene.render.ffmpeg.format = 'QUICKTIME'
    scene.render.image_settings.color_mode = 'RGB'
    scene.render.ffmpeg.audio_codec = 'AAC'
    scene.render.ffmpeg.audio_bitrate = 128
    scene.render.resolution_percentage = 100

Also see the API docs.


Using the "Repair" option with a fresh download of the installer from blender.org did the trick. Also fixed GPU rendering abilities


Number of vertices and edges report no changes after adding boolean intersect modifier

Use the evaluated object
Modifiers don't alter the mesh, they "Modify, Generate, Deform or Physics" the mesh result ... using the mesh as input.  Think of it like a method in mathematics sin(x) doesn't alter x it returns a result using x as input.
The result is available in newer versions of blender as the evaluated object.
How do I get a mesh data-block with modifiers and shape keys applied in Blender 2.8?
This is the result of all modifiers applied. It in no way applies the result to the mesh.  As with most modifiers they are often not easily reversible if applied, and is not required to simply test if geom would be changed.
Test script looks at difference between edge count of cube unmodified and with all modifiers.
import bpy
context = bpy.context
scene = context.scene

cube = scene.objects.get("Cube")
cone = scene.objects.get("Cone")
if cube and cone:
    print(len(cube.data.edges))
    bm = cube.modifiers.new(name="Foo", type='BOOLEAN')
    bm.operation = 'INTERSECT'
    bm.object = cone
    dg = context.evaluated_depsgraph_get()
    eval_cube = cube.evaluated_get(dg)
    print(len(eval_cube.data.edges))

A better option would be to look at the evaluated object both before or after to see the change in evaluated meshes. (eg the cube could already have a stack of modifiers)
import bpy
context = bpy.context
scene = context.scene

cube = scene.objects.get("Cube")
cone = scene.objects.get("Cone")
if cube and cone:
    cube.evaluated_get(context.evaluated_depsgraph_get())
    print(len(eval_cube.data.edges))
    bm = cube.modifiers.new(name="Foo", type='BOOLEAN')
    bm.operation = 'INTERSECT'
    bm.object = cone

    eval_cube = cube.evaluated_get(context.evaluated_depsgraph_get())
    print(len(eval_cube.data.edges))
    cube.modifiers.remove(bm)

If the mesh has no modifiers of shapekeys prior to adding could check for this to avoid an unrequired evaluation.
prior_cube = (
    cube.evaluated_get(context.evaluated_depsgraph_get())
    if (
        cube.data.shape_keys
        or cube.modifiers
        )
    else
        cube
    )

Test run, default cube on RHS has subsurf modifier. Results (before, after) are 12, 64 and 92, 192
An interesting technique to test for intersection.  Could be on the slowish side.  Looping over objects getting data and adding modifiers, then looping again would require only evaluating  the context depsgraph twice instead of twice for each object.


Wondering how to make an iridescent and slightly translucent object?

Here is a try (that works with both Eevee and Cycles), it's a mix between a Diffuse and a Translucent node, mixed with a Glossy that has a greenish color to get greenish reflects. Use a texture to get the streaks effect.

The image texture I've used:


The pipes are made from faces that are disconnected, this keeps each face as a flat surface.

In edit mode, select everything A and remove doubles W->Remove Doubles. You may also want to use ⎇ AltJ to turn all the triangles into quads to cleanup the mesh.


Color difference in saved images vs Render View

I have a feeling somebody is going to say "that's just how color spaces work" and tell me to play with the Color Management settings... but even if that is the answer I would appreciate getting some clarity on this matter. Thanks.

If you ever catch someone saying this, kick them. There is very little that could be further from the truth.

Sadly, your question cannot be effectively answered without further information. You mentioned that you are on MacOS, which means that your display could be quite different from the assumptions that most folks would make here. Most importantly, if you are on an Apple device that is from 2015 onward, your colours are going to be entirely wrong. That's right, Blender doesn't support Apple devices via the default installation.

The fastest way to get WYSIWYG is to properly tag your image with the Microsoft / HP sRGB ICC profile.

The following command should attach a profile with the help of the ImageMagick tool:

convert source.tif +profile MY_PROFILE_PATH/whatever-profile.icc destination.tiff

If you offer up further information, it can help to completely solve your problem here.


More or less something like that ?

The membrane is simply a mix between glass and glossy and a manual adjustment of a fresnel node to handle the mix factor.

The DNA is base on the same principle, but with diffuse and emission :

But for the sticky effect this is mainly a displacement texture (a cloud texture) on the membrane :


Scroll wheel zooms when using Loop Cut And Slide

Fortunately I stumbled over the solution for this. It has nothing to do with OS or how Blender is installed.

It's simple: If you click Loop Cut in the tool shelf, you get the crippled behaviour with scrolling and not being able to slide the new cut. But if you use Loop Cut And Slide with the shortcut Strg+R, it behaves as usual. I've tested it with Blender 2.79 and can confirm that you get the same behavior regardless of how you start the tool.


How to turn on Eevvee rendering live preview?

I found Rendered Shading in the Shading menu on the bottom of the 3D view window.


Blender Rigid Body Physics Trapdoor Effect

For completeness, far fetched problem sources are included.

The cans should be set to active and dynamik. Since they are cylinder-shaped, I will set the shape to cylinder.
The enclosing platform should be set to passive. The shape property is set to mesh.
The trap door should be set to passive and animated.