Better Kitbashing and Asset Management flow, with multiple kits? Organize and browse assets?

External solutions or addons are the way to go. My method was to experiment all the tools I could find that could deal with problems (1) and (2) described in the topic, with special care in which tool would allow to manage, browse and quickly drop big kitbashing kits into Blender.
The two final solutions that "passed the tests" are:
Connecter (https://www.designconnected.com/connecter/)
From their website:

Free and visual creative assets management for 3d, AEC and design professionals.

Connecter consists of two components:

A native Desktop software, where you catalog assets of all kinds, by folders, tags and more. It supports all 3D formats, including .blend files natively as well textures, materials, videos, and more.
A Blender add-on, which allows you to tag objects directly in Blender to be added to Connecter and also to RECEIVE INCOMING DROPS from Connecter, and this is where it shines in terms of asset management for Blender.
Video showing the process with Blender on Youtube.

Asset Management (https://gumroad.com/l/asset_management)
This is a paid Blender addon that adds a "Content Browser" into Blender, for all kinds of assets.

Its biggest advantage is that it's made for Blender only, so you can expect tight integration with all kinds of Blender objects and data.
The disadvantage is that you can't manage the assets outside Blender and you can't have other model formats (fbx, etc). You have to convert everything to a friendly Blender format.


Re-download and extract the Blender zip file making sure everything is copied over.

When you downloaded Blender 2.8 Beta it should have been in a zip file. Extracting the zip file would have taken time and if not every part of the zip file was extracted then parts of blender don't work properly

I learnt this by running Blender before everything had extracted.

Here is a photo of my Blender folder:

It has 72 items in it (including the '2.80' folder) and Blender runs fine.

My guess would be the part of the file which detects keyboard clicks is not there so re-download the .zip file and extract it making sure everything is copied.

I can't say for sure if this will work but hopefully it does. If it doesn't then I don't know what else to do and I am sorry.


Is there any way to select everything that is not currently selected?


"Track to" and animations at the same time?

You can achieve the behavior that you want by parenting your empty with the recoil animation to the empty that tracks to the center of the screen.

           Tracks to the center                         Emits projectiles + plays recoil animation

When your projectile emitting empty is parented to the tracking empty, it will still track to the center of the screen, and your bullets will vary in direction depending on your animation on that empty.

I think this is the effect you are trying to achieve


How can I best combine different objects in a way that reduces vertices and edges?

The Boolean modifier should work perfectly for this purpose.

First, split the separate parts into individual objects (P with everything selected in edit mode).

Then, add the Boolean modifier to either of the objects, set it to Union, and select the other object. You can further edit the mesh by applying the modifier (⎈ CtrlA).

After applying the modifier, you will be left with two objects: the joined mesh and the target object of the modifier.


Is there a way to fit the viewport to the current field of view?

While trying to figure out how to manipulate bpy.context.screen.areas[5].spaces[0].region_3d.view_camera_zoom , I accidentally discovered that the Home key will make the camera bounds fill the viewport.  If you try 'View All' from the spacebar menu it doesn't work exactly like the Home key (could not be bothered to hunt down why).

While not exactly useful, the examples at http://web.purplefrog.com/~thoth/blender/python-cookbook/screenshot-sequence.html might get you a little closer to the solution.  Specifically

def viewMatrixFromCamera(cam):
    """
    :param cam: the camera whose point of view is of interest
    :return: the view matrix suitable for use in region_3d.view_matrix
    """
    m2 = cam.rotation_euler.to_matrix()
    m2.resize_4x4()
    m3 = mathutils.Matrix.Translation(cam.location)
    return (m3*m2).inverted()

def viewFrom(screen):
    """
    :param screen:
    :return: the "first" area in the specified screen that is a 3D view.
    """
    for obj in screen.areas:
        if (obj.type == 'VIEW_3D'):
            return obj
    return None

v3d = viewFrom(bpy.context.screen)
m1 = viewMatrixFromCamera(bpy.context.scene.camera)
print(m1)
v3d.spaces[0].region_3d.view_matrix = m1

Unfortunately this exact code is NOT what you need when you are actually looking through the camera.  It only works to set the view when you are NOT looking through the camera.

Another problem is that while the code does move your focal point to the camera position, and gives you the correct orientation, it is highly unlikely to match the focal length of the camera.  I have not been able to find any setting on the 3D view that allows you to adjust the focal length when you are not looking through the camera.  When you "zoom in" you really just move the 3d view's focal point closer to the center point.


Very bad performance on Cycles OpenCL using Ubuntu 18.04 and Radeon VII

Have you tried updating Ubuntu to 18.04.2 with HWE (4.18 Kernel) and AMD's most recent 19.20 driver?

A few months ago I had issues getting my Dual RX Vega64 setup working (on a Ryzen 1700 system with Ubuntu 18.04): Just a single GPU worked fine, but when I installed both GPUs, Blender refused to use any of them for OpenCL rendering with Cycles.

Some debugging and writing small test programs later, I figured out the AMD's driver refused to open an OpenCL-context on the Dual-GPU-setup when already an OpenGL-context had been opened before. (With just a single GPU installed this worked fine, though.)

Since then I updated my Ubuntu to 18.04.2 with HWE (Linux 4.18 kernel, instead of 4.15 without the HWE) and updated my driver to the new 19.20 version, and now my Dual-GPU-setup works fine out-of-the-box as if nothing ever happened (with rendering speed-up of 50-100% compared to my single-GPU-setup).


Hide smoke domain objects in OpenGL quick render

If your domain's Maximum Draw Type is set to Wire (Object Properties > Display panel), you can set the 3D View's display to Only Render (Properties region [N] > Display panel) and the domain should be hidden from view.


not able to conect nodes in the compositor

I had the same problem. It looks like having two areas of the interface displaying nodes is causing this bug.
Just close the other nodes area(s) and it should be back to normal. It worked for me !


Deform an array of objects without modifying its geometry, just the relative position of them

You can use a "dummy" object to parent your array object to.

Here I've created a two dimensional array of planes and applied two Curve Modifiers... one the for the X and one for the Y direction:

Once that's done, create one instance of your object and parent it to the plane array by going to Object Properties and selecting the plane.

Right Click on the plane and enable duplication with "Faces" as the method.  This will create an instance of the child (sphere) for every face of the plane array.  You can manipulate the curves under the plane to give you the desired bend.

EDIT: An alternative would be to apply and separate the array elements and use the Proportional Editing Tool to position them:

1.) Apply the Array Modifiers

2.) Go into Edit Mode and Select All by pressing A twice.

3.) Press P and separate by Loose Parts

4.) Go back to Object Mode, select all the new Objects, and set their origins to the center of the spheres: Shift Ctrl Alt C

5.) Select the middle sphere and enable Proportional Editing in the toolbar.

6.) Translate the sphere in the Z-direction and use the scroll-wheel to adjust the size of the Proportional Translation.


Is it possible to export shape keys to c4d pose morph?

Ok, I managed how to do it :
In the blender fbx export options, "apply modifiers" must be unchecked :

Import fbxinto c4d, and so are the blender's shape keys converted to c4d's pose morph :


Iterate through objects then parent and add material based on string search in names

Use string.split.

As you are already familiar with programming, and without a test file, will run thru an example. Use pythons String.split to split the name as is into a list using the underscore as a separator.  If there are 4 members in the split etc..

import bpy
context = bpy.context
scene = context.scene

def parent(name):
    ob = scene.objects.get(name)
    if not ob:
        ob = bpy.data.objects.new(name, None)
        scene.objects.link(ob)
    return ob

def material(name):
    ma = bpy.data.materials.get(name)
    if not ma:
        # add a new material as in link
        pass
    return ma

# iterate thru all obs in scene
for ob in scene.objects[:]:
    split = ob.name.split("_")
    if len(split) != 4:
        continue
    a, b, c, name = split
    ob.parent = parent(c)
    # add materials etc.


.fbx export why there are no materials or textures?

This is a frequently asked question.
TL;DR
Most file formats just don't support exporting textures, let alone full blown material definitions or other application specific features. Also most Blender importers/exporters don't currently support node based materials well.
Manually reproduce your materials using available textures at the target environment.
Long story
Materials are too implementation specific and tightly tied to the rendering system they belong to, or software they were created with. You can't, for the most part, import/export material definitions between applications, you can't even get Blender Internal Materials to work with Cycles Renderer nor vice versa, and  they are both created with Blender, let alone between completely different applications.
For this reason no file format you use can, or even tries to, import or export material properties, be it 3DS, FBX, Collada, STL, OBJ or any other. These are mostly mesh-only, geometry-centric file formats concerned with porting object shapes, and some times animation, armature, and basic shading, or color properties (like MTL files); never full complex material definitions.
There are simply no data structures in the specifications for most exchange file formats to accommodate that data, let alone all possible types of properties, settings or maps; and even if there were, there are way too many different rendering implementations for a variety of purposes and responding to distinct requirements (like speed or responsiveness for real time rendering engines or games, or realism for physically based 'offline renders'), and each using its own different set of parameters and particular ways of interpreting specific properties to be able to correctly match settings, parameters or particular features between them easily.
For example most real time rendering systems have need for some form of explicit "backface culling" option because rasterization relies heavily on it for performance reasons, yet in render like Cycles it is just a basic node because for raytracers it is irrelevant which direction a geometry faces. On the other hand glass and transparent shaders "just work" with great refraction in raytracers, yet in EEVEE you need to muck about with blending modes and transparency settings, nonexistent in Cycles, because representing object interactions is expensive and complex for rasterizers.
Some more common image based texture channels may some times be correctly preserved, like diffuse, specular, glossiness, or the increasingly popular "PBR workflows", but certainly never procedurally generated textures and/or generated texture coordinates, these are generated at render time and can't be exported. Have in mind that most Blender exporters do not even support Cycles node based materials at all (at the time of writing for Blender 2.79#), so even image textures used in Cycles node trees are most likely not expected to be preserved.
Same applies for many other features specific to applications or render engines, like lighting parameters, shadow settings, lamps, cameras, physics simulations (fluids, cloths, soft bodies), texture options (clamping, clipping, tiling, color adjustments), generated texture coordinates (anything not mapped explicitly by a UV map or created by unwrapping a mesh), material options (backface culling, shadows, visibility, transparency and blending modes) particle systems, smoke and fire sims, volumetric data, modifiers, shape morphing (like shapekeys or deformation based animations) and other "generated data", can't also for the most part be imported or exported (with a few exceptions).
How to solve it then?
All you can, and should, import/export are UV coordinates with your mesh so you can correctly apply your textures at the "target application", game engine or receiving rendering environment, where you'll be importing and displaying your model, be it Unreal, Unity, Gamekit, external rendering software or whatnot; or even Blender itself when importing models from elsewhere. UV maps are generally correctly preserved by most exchange file formats by default.
There you should spend some time recreating your materials from scratch again with the provided textures and available maps. Yes, it requires some backtracking and will take some time, but with practice it'll get quicker. Save presets into reusable libraries when available, to reduce the amount of repetition.
What you can do in some situations is use Blender to bake textures that you can later use in the final destination or receiving application to create materials there, not inside Blender.
Baking is the process of pre-calculating shading and storing it in a static image texture that may incorporate several optional channels like diffuse, glossy, indirect lighting, bump maps, normal maps, light-maps, among others. This may improve graphic quality or perceived "realism" at the expense of dynamism, as certain properties of materials and textures may become static, as if "painted onto the surface", like shadows or reflections. This is often a requirement for high performance mediums or low power platforms, like web or mobile gaming, where available resources are limited or unknown, and speed takes precedence over graphic fidelity.
Exceptions
One notable exception to all this is the glTF file format, which as of version 2.0 glTF does support some material definitions based on a metallic-roughness shading model in its specs. The glTF-Blender-IO addon created by the Khronos Group themselves supports exporting Principled BSDF node based materials. But even then some restrictions apply.
Due to the recent popularity of the Physically Based Rendering, and its increasing use in Game Engines and Real-Time rendering applications, it has become a sort of vaguely defined "loose standard" for describing surface properties of materials (although several differently nuanced versions exist).
Future Developments
PBR is not a standard however and not every implementation works the same way or interprets the same parameters similarly. The Principled BSDF was already written according to a model designed by an established industry leader (Disney) for their own internal use, and game engines like Unreal Engine® or texture painting applications like Substance Painter® also adopted it.
As the PBR workflow gains popularity and traction it is possible that more applications "join the movement" and implement it in the future. If a common standard can be agreed upon, it may be possible that in the future more importers/exporters improve compatibility with an increasing number of materials properties. They will likely either read directly from a Blend file, use some other hypothetical new file format, or be forced to implement new standards; as the current ones still lack data structures to correctly describe them. At this point it is pure speculation, and no known plans are made.
Related Issues

Importing OBJ with MTL and Image not working properly
When I save something as an OBJ file the texture does not save with it, why?
How to import a .mtl file?
Blender isn't importing mtl correctly with obj?
Export cycles material to unity
How to Import a model with textures applied?


Mirror Modifier making ugly smoothing on mirrored faces

You have custom normals on this model, the normals for some reason now point in strange directions.

In the mesh properties navigate to "Geometry Data" and press "Clear Custom Split Normal Data".


How to model and animate a bifurcated path?

Curves cannot be forked to create branches. And if you create more than one segment within the same curve object you won't be able to adjust an animation of those segments independently. You need separate objects.

As an example:

Let's say you animate the bevel Factor of a curve by animating the End, setting a keyframe with value 0 at frame 0, and one with a value of 100 at frame 60.

To make keyframes just hover the cursor over the value and press I.

Then you create a new segment with a new curve object and align it to start where you want the fork to start. A single curve cannot be animated at different rates in different segments, that is why it has to be a separate new curve. In this example I'm using the snap to function (Shift+S) to place the new segments precisely over the older curve.

Animate the start and end of the bevel for the second curve so that it starts at the point you want.


Why are these Grease Pencil objects moving together when I animate them?

The issue is that both of your objects are one single Grease Pencil object. If you look in the Outliner in your video (to the right), you will see that you have something highlighted in the list called Stroke. And both of these objects are part of it. Hence, why you can't move them independent of one another. If you want independent objects in 2D, you need to create a unique grease pencil object for each of them. This can be done in Object Mode, from the Add menu (Shift + a).


How to create a "linked copy" scene in Python without using ops?

As far as I can tell, bpy.data.scenes['your_scene'].copy() will give the exact same result as bpy.ops.scene.new(type='LINK_COPY') except for one detail: the new scene has 0 user and gets added to the orphan data.
This is not an intended feature and there's no python command to properly fix that. However, there's no need to worry, as the scene will actually not get deleted if you save and revert the file, contrary to any other orphan data.
Still, if it's uncomfortable for you, it's possible to give the scene 1 user by doing any of these:

adding a fake user: bpy.data.scenes['your_scene'].use_fake_user = True

or

saving and reloading the file

or

performing any operation and undoing it with Ctrl+Z (currently, the undo operator reloads many components of the file so I guess it works for the same reason reloading the file works too)

Side note:
You can also do the equivalent of bpy.ops.scene.new(type='EMPTY') (called "Copy Settings" in the interface) this way:
Sc = bpy.data.scenes['your_scene'].copy()
for col in Sc.collection.children:
    NewSc.collection.children.unlink(col)
for obj in Sc.collection.objects:
    NewSc.collection.objects.unlink(obj)


Make a hemisphere/dome from flat segments?

I don't think this topology is the best to make a dome, but here is a solution:

Make sure you've applied the scale of your object.
Shift a bit your mesh from its origin.
Create a curve which follows approximately the curve you want. Check the direction, put its origin at its bottom.
Give your mesh a Curve modifier with the curve as Object.
Create an empty at the same point as the mesh origin.
Give your mesh an Array modifier, give it a Count of 6. Enable Merge, choose the Object Offset mode with the empty as Object.
Rotate the empty 60° on the Z axis. The object should rotate around the Z axis.
Shift the mesh a bit so that its bottom stick to its duplications bottom.
Edit the curve so that the sides of the mesh stick to its duplications.
Edit the object: Select some horizontal edges and scale a bit with the Proportional Editing enabled, so that the vertices of the mesh stick to its duplications.
Once you're glad you can apply the modifiers and remove the doubles (but keep a copy somewhere).
You'll have to make some additional editing to clean it a bit, create some nice edges with bevels, and to avoid artefacts. I've also used a W > Smooth. You may want to work only on 1/6 of the dome and re-use an array to duplicate it again.


How to import Cad models into Blender the easy way

Press P and choose by Loose Parts. That creates a separate object for each group of connected vertices.


If I combine two objects by pressing Control + J, one side becomes strange

From what I see, you've mirrored one object by scaling it negatively from the other (look at the scale values, one is negative on X while the other is positive). Which under the hood kinds of turns the mesh inside out twice like a sock.
But when you join the two meshes together, you lose the scale value from the joined object, which is replaced by the target object. So you end up with reversed faces.

To fix that, simply enter edit mode, select everything with A and hit Ctrl N to recalculate the normals.

Besides that, if you know you're gonna model mirrored parts, you should use the Mirror Modifier. It's a more efficient tool, on top of being reversible, editable at any time, and gives you more modeling possibilities.

One more thing :
By looking at your object, you can see that they have uneven scales, not equal to 1, as well as some rotations.
It might be intentional, but usually, you want to keep your objects scales equal to 1, or at least even (if uneven, you will have troubles while modeling, texturing and so on). Rotations should be usable ones (90s, 45s, .... are ok, but "-0.000001" are not) unless you do need those.
So you might want to apply those transformations or undo them, depending on your needs. To apply transformations, use Ctrl A menu. To undo transformations, use the shortcuts Alt G/R/S (G for location, R for rotation, S for scale).


The problem is, that the animation uses so much space, that it doesn't appear anywhere near the center. You could scale the armature and its animation while importing

or use the Graph Editor, which is more flexible.

You can use the Graph Editor to move G and  scale S the F-Curves accordingly. Select the Armature ("bag") in the Outliner, switch to Pose Mode, press A to select the bone and switch a window to Graph Editor.


You could create vertex-groups for each ring that should get another color when when hit by the character like this:

Assign each ring its own material with the same color at the beginning. When the character hits the background object determine which polygon has been hit by a technique described here:
How do I make a weapon shoot at the center of the screen? find the face hit by the character and set the material's color to a random color, this would change the color of faces (because all of the them share this material).


How can I use my Blender models in WebGL

The answer is somewhat dependent on what file format the WebGL viewer ingests. And how good the Blender exporter is. But the most common format is probably the ASCII Obj format, for which Blender has a pretty decent exporter for.

So, things to watch out for:

Geometry: Avoid Ngons, or at least, triangulate before exporting. The exporter might produce unexpected results. Also, make sure the face normals are all oriented correctly. Blender renders both side of a polygon by default, many other 3D viewers don't. You can recalculate normals with Ctrl + N.

Mesh Modifiers: Even though the exporter probably applies the modifiers. It's better to be explicit than implicit. Also, it is a good idea to apply the transforms (Ctrl + A).

Materials and Textures: Avoid the Blender material panel(except basic colors). Use UV-mapped textures. Blender-specific features like procedural textures are not going to migrate properly. Image textures dimensions should be power of 2 square. (1024x1024, 512x512, etc)


Colour ramp in 2.8 only picks the last colour stop.

It's probably because Blender 2.80 is in beta.
However, there is nothing wrong with the color ramp node; it is actually the sky texture node returning solid white. Until sky texture is implemented, you can render out a full spherical HDRi (512x256 res 16bit .exr recommended) with 2.79 and use that in place of the sky texture.


Create a translucent plastic node setup/bump map for "ice pack" material

This should be rather simple. Just use a noise texture (softened by runiing through a MixRGB with white) and a Bump Node to get the surface bumps. Then, create the "icy" (translucent) gel effect by using a small Subsurface Value (0.3) and a blue color.

If you want to go deeper on the gel effect, try increasing the blue and green values only of your Subsurface Radius:


How do I change the linear stiffness of an object programmatically?

If you simply want to batch-modify physics values on objects, you could do something like this:

import bpy

for obj in bpy.context.selected_objects:
    if obj.game.physics_type == 'SOFT_BODY':
        obj.game.soft_body.linear_stiffness += 0.1 #or whatever other operation

I'm not really familiar with the BGE, though.


Dimensions added using MeasureIt addon not appearing in final render

If you click on the View menu of the viewport area of interest, you can choose Viewport Render Image option.
Disabling overlays  keps the measureIt overlays, so you can use that to your advantage:

In order to get your measurements rendered, all you would have to do is:

Click on the Render button in the Render panel which is going to render your measurements as a separate image based on the active camera
Open up a new Compositor window or just switch the workspace to Compositing, add an Image as well as an Alpha Over node
Set the image for Image node to generated image by the MeasureIt add-on
Plug your rendering into the upper socket and the generated image into the foreground (lower) socket of the Alpha Over node

Also have a look into the manual: https://docs.blender.org/manual/en/latest/addons/3d_view/measureit.html.


Your render looks blurry because of the low samples in the render tab. As you can see in the picture you have 2 sliders, one that says preview : That's the one you use if you go to render mode. And the other slider that says render. That is if you use a camera and render it from there by clicking on the render button above the sampling. I but the render slider way down just to show you the difference.

Now because I use a camera to render this monkey I set the render slider higher to get less noise (blurriness)

Hope this helps.


Map Brick Procedure Texture onto Correctly Scaled Models

In Order to get the right dimension for your tile material onto the UVW map.

1 . Use UV Project From View, while in top view.
2 . If your object is a wall then you will need to use the front, left or right view.
3.  Select "Orthographic" option in the tool panel ...
4.  This will match your object you have modelled to scale.
5.  These are the brick procedure texture settings

      a. Offset 0.00
      b. Frequency 1.0
      c. Squash 1.0
      d. Frequency 1.0
      e. Scale 1.0
      f. Mortar Size 0.002
      g. Bias 1.0
      h. Brick Width 0.300 (In metres)
      i. Brick Height 0.300 (In metres)

0.3 metres is exactly 300 millimetres.

EXTRA NOTES

  It is important to note that if you have accidentally/intentionally scale up
  or down your object in Object Mode, you will be required to apply scale before
  attempting the UV Unwrap of the model as incorrect scale will interfer with the
  unwrap.


Understanding the nature of a Blender render

A render is exactly as you say in your first bullet point; a render is a snapshot (or series of snapshots for animations) of the scene taken by the scene's camera, saved as either an image, a sequence of images or a video. The file format will be whichever format you save it in e.g. JPG or PNGs etc. for images or MP4 or MOV etc. for videos.

The process of creating this render is rendering, which is where the renderer - Blender Render, Cycles or an external render engine - calculates what colour each pixel should be based on how light is travelling through the 3D scene and interacting with the surfaces, materials and textures on the objects. This can be an intensive process, particularly for animations where a render has to be done for each frame of animation.

For a 3D game, game engines will need the 3D models and textures in a format it can read. Commonly, you would export your models from blender as 'FBX' or 'OBJ'. These files store the 3D models as a series of points (along with other data like bones, UV maps etc.). Textures would have to be provided separately and materials would have to be created using the game engine's own material editor as they are not compatible with Blender's own materials.
To get around this you might create materials in Blender and Bake them to a texture, which is a way of rendering a material into a texture so that you can use it in the game engine (though baking has many restrictions which may mean that using the game engine's materials and lighting is preferable).

Game engines perform a 'live' rendering where for each frame (update) of the game engine the materials and lighting have to be re-calculated. Depending on the complexity of the materials and models this can be an intensive process which is why high end hardware may be needed for this 'live' rendering.


How can I use a driver for multiple objects?

If your driver is: max(0, min(pi/2, 2-abs(v1))), where v1 variable points to the car's location component of the axis perpendicular to the gate, then you already use max which is the method to take the bigger out of two (or more) values.
So you can calculate the bar's rotation for all cars on the scene, and pass each to the max function so the bar is always as low as the closest object in the equation allows it to be. Therefore, the driver becomes max(max(0, min(pi/2, 2-abs(v1))), max(0, min(pi/2, 2-abs(v2))))

In your case you have to add distance2 to have a distance of the second car to the gate. Then you apply the above advice with max:
max(pi / 2 + (abs(distance/15) < 0.8) * (pi * 3/4 - abs(distance / 5)), pi / 2 + (abs(distance2/15) < 0.8) * (pi * 3/4 - abs(distance2 / 5)))


Camera shakes like heat shimmer or mirage

Problem was, the camera's clip start was too small (0.001), which was fine for an interior shot, but as soon as the camera went outside it had to be set higher (0.100).
Cheers


As far as I know Blender Player only runs on Windows, Linux and Mac. And to a much lesser extent a basic Android version.

Did not know about FreeBSD on PlayStation though, but on Android it was pretty much a proof of concept. It's feature incomplete and experimental, without any kind of support or continued development.

Have in mind however that the Blender player is  sort of a dead end. It is considered old and outdated, and development has sort of stalled. It is also considered for removal for the future Blender versions

A much more modern and future proof technology would be browser based WebGL technologies which have good support in every modern browser and mobile platforms and also have some extent of VR Support.

Blend4Web is a great Blender Addon which removes much of the need for coding, while being open source and free for personal use.


Why is there a depression in my render even though there is none in the wireframe?

In this case, some of your normals have become flipped causing problems with your shading. To correct this, go to edit mode, then Select all > mesh > normals > recalculate outside.


When you hard-cut in the VSE, does the current frame end up on the left or right side of the cut?

I have here 15 frames, each one with a number on it.

When I followed what you did, frame #10 got cut into it's own strip, which can be deleted:

This are the surrounding frames:

I don't know what you are doing wrong, because it works for me.

What this means is that the frame moves to the right of the cut.

Based on this, what you should do is:

Move to the frame you want to cut.
Enter Shift + K
Move 1 frame to the right
Enter Shift + K again
Select the middle frame and delete it.
Select the next strip and move it 1 frame to the left.


Well, I discovered my error.

I was using Cycles and not Blender Internal.  Unless there is some setting I am unaware of, Cycles does not save the texture data in the exported .X3D file.

So just simply switch to Internal render and then add your textures.


Edge split to make flat edge not working

The X shaped shadow in your shader might be due to the triangles leading to the inner circle, you could try deleting those triangles and recreating using quads instead:


How can I call a specific keymap to draw within my AddonPreferences?

You're likely the first person who has attempted this, and it looks like its quite possible;

Notes

Save this script to your addons dir with a unique name (ending with .py)
The keymaps are added as is normal for an addon.
There is one bug at the moment, pressing the 'X' buttons isn't properly removing them. (needs further investigation we should be able to fix)
Finally - this uses a part of the API we consider internal, so its not guaranteed to work in future versions (realistically it probably wont change any time soon though).

Script:

bl_info = {"name": "KeyMap Test", "category": "Object"}

import bpy
from bpy.types import Operator, AddonPreferences
from bpy.props import StringProperty, IntProperty, BoolProperty

# this is an internal API at the moment
import rna_keymap_ui

class ExampleAddonPreferences(AddonPreferences):
    # this must match the addon name, use '__package__'
    # when defining this in a submodule of a python package.
    bl_idname = __name__

    filepath = StringProperty(
            name="Example File Path",
            subtype='FILE_PATH',
            )
    number = IntProperty(
            name="Example Number",
            default=4,
            )
    boolean = BoolProperty(
            name="Example Boolean",
            default=False,
            )

    def draw(self, context):
        layout = self.layout
        layout.label(text="This is a preferences view for our addon")
        layout.prop(self, "filepath")
        row = layout.row()
        row.prop(self, "number")
        row.prop(self, "boolean")

        col = layout.column()
        kc = bpy.context.window_manager.keyconfigs.addon
        for km, kmi in addon_keymaps:
            km = km.active()
            col.context_pointer_set("keymap", km)
            rna_keymap_ui.draw_kmi([], kc, km, kmi, col, 0)

class OBJECT_OT_addon_prefs_example(Operator):
    """Display example preferences"""
    bl_idname = "object.addon_prefs_example"
    bl_label = "Addon Preferences Example"
    bl_options = {'REGISTER', 'UNDO'}

    def execute(self, context):
        user_preferences = context.user_preferences
        addon_prefs = user_preferences.addons[__name__].preferences

        info = ("Path: %s, Number: %d, Boolean %r" %
                (addon_prefs.filepath, addon_prefs.number, addon_prefs.boolean))

        self.report({'INFO'}, info)
        print(info)

        return {'FINISHED'}

addon_keymaps = []

# Registration
def register():
    bpy.utils.register_class(OBJECT_OT_addon_prefs_example)
    bpy.utils.register_class(ExampleAddonPreferences)

    # Keymapping
    kc = bpy.context.window_manager.keyconfigs.addon
    km = kc.keymaps.new(name="3D View", space_type='VIEW_3D')
    kmi = km.keymap_items.new("object.editmode_toggle", 'NUMPAD_SLASH', 'PRESS', shift=True)
    kmi.active = True
    addon_keymaps.append((km, kmi))
    kmi = km.keymap_items.new("object.transform_apply", 'NUMPAD_SLASH', 'PRESS', shift=True)
    kmi.active = True
    addon_keymaps.append((km, kmi))

def unregister():
    bpy.utils.unregister_class(OBJECT_OT_addon_prefs_example)
    bpy.utils.unregister_class(ExampleAddonPreferences)

    # handle the keymap
    for km, kmi in addon_keymaps:
        km.keymap_items.remove(kmi)
    addon_keymaps.clear()


Because you are in edit mode?
If you want to affect object by modifier in edit mode press triangle icon.
For more informations about modifier see manual.

What is this triangle icon? Blender Manual sayes:

Show on cage (vertices-triangle icon) – Meshes only

Depends on the previous setting, if enabled, the modified geometry can also be edited directly, instead of the original one.

Warning

While it shows edited items in their final, modified positions, you are still actually editing original data. This can lead to weird and unpredictable effects with some tools, and should be disabled whenever you need to perform complex or precise editing on the mesh.


Cut a model into two models by intersecting with a third model

You can use a Boolean modifier.

create 2 different objects (i.e. cube and sphere), and position them where you like the "cut" to happen:

Add a Boolean modifier to the cube:

Set object to sphere and operation to difference:

Apply modifier and delete the sphere:


Animation Nodes: How to snow in the text?

Starting from the position of each of the characters, create a random walk biased in the direction of the positive y axis. The random walk is easily done using a loop as described in the documentation. The path of the walk for the first character is shown below:

We are going to edit this slightly such that the first random step has no x component so that the tangent to the path at this step is pointing along the y axis, this will ensure the character will be upright when it reaches this point if we orient it based on the tangent. This is done by multiply by zero if it is the first step, that is, if the index is equal to zero. We will also add a Seed Offset, which is just an integer that is added to the seed to differentiate between different splines:

Then, we are going to loop over the character positions, use their positions as the initial point of the random walk, and their index multiplied by the resolution of the spline as their offset seed. The outputs of the random walk is used to generate a spline which is then evaluated based on some parameter iterator:

Finally, we generate the parameters using an inverse delay falloff and orient and position the the characters based on the output positions and tangents:

To achieved the second effect, simply shuffle the parameters list and maybe reduce the delay:


How can I trim a face thats overlapping another face?

I'm not sure what you are asking but I'll try. you can pull back the part that is sticking out in edit mode. Select the 2 vertices hanging out in edit mode with vertex select checked. Press g to grab and x, y, or z to move along an axis press esc if it goes the wrong way and try again. You can use snap tools to get the mesh to connect properly and not overlap- google: blender snap. I don't think you can just delete the part hanging over unless: there are vertices where a and b intersects then just delete the face hanging over by selecting it and hitting the delete key ( I don't think that is your case though if it was just pulled to far when extruding). alternatively you can delete B, insert a loop cut on face a and extrude from that with the edge selected and snap to what you need to. that might not work to well though unless you are aiming to extrude from the dead center of of face a. after deleting b and inserting a loop cut you could also select the four vertices you want to fill and press f. Hope that helps I didn't understand the problem with C but it might cover that too.


How do I cite Blender builds/release correctly for Publications using Bibtex?

Blender has no functionality to do this, but you could use a Python script.

def citation():
    import bpy

    build_year = bpy.app.build_date.partition(b'-')[0].decode('ascii')

    return '''\
@Manual{,
   title = {Blender - a 3D modelling and rendering package},
   author = {{Blender Online Community}},
   organization = {Blender Foundation},
   address = {Blender Institute, Amsterdam},
   year = {%s},
   url = {http://www.blender.org},
 }''' % build_year

# test to see it works:
print(citation())


Sadly, this isn't possible. There are some good reasons why though.

If you think about it, when you add your cylinder, you have all your settings there. The settings will always be for the last operation done. When you do another operation, the old settings are gone, and are replaced with the new settings for the operation you just did. There isn't a way to go back to previous settings without going back and redoing your steps, because it's not really practical to keep those sorts of histories, especially when mode changes come into play.


Is it possible to Link one or more layers from another .blend file?

It will be easier to do that the other way around - link objects from the original scene into new one within one blend file.

In that case you have the freedom to select objects as you wish, including selecting objects by 3D layer, selecting all the children of the parent or vice versa via Select Grouped menu and so on.

Once objects are selected, in Object mode press Ctrl+L > Objects To Scene (additional scene should be already created). You can either render from that additional scene or link/append the scene into another blend via Append or Link and choosing Scene.


Spot light not working in render or the game engine

Spotlight only works well in the game engine when the draw mode is set to 'GLSL'. You can change that setting in the attribute editor.


How would you create Pixel Art in blender without using a Shader?

GUYS I FINALLY WORKED IT OUT :D

After literally asking him online  through social media; he answered! Credits to Leon Cheung and Carlo for being correct on the whole process. He uses the Import > Image to Plane feature addon within Blender. Furthermore, he stated that instead of creating armatures and a rig for his assets, he uses plane animation to move each plane.

I'm really grateful to all the responses i received within the time of this post. Hope this finally cleared it all up <3

Here's something I created with the knowledge i gained:


What does texspace_location and texspace_size mean? in the blender Mesh Data

It doesn't have anything to do with UV, it transforms texture space (for box mapping etc.). Turn on Texture Space to see it:

And in Outliner in datablocks view under meshes>your_mesh if you turn off Auto Texture Space you can fiddle with the values and see what they do:


Switch to top view, then in edit mode select all the mesh, hit U button to unwrap and from the menu select Project from View (Bounds)


Your question is not too clear.

If you cannot get back to the 3d view port,  press escape and it should take you back.

If you're renders are staying the same, uncheck sequencer shown below.

If none of these answered your question, please specify in more detail.


Every animation you do will create a - so called - "action" which is a datablock that can be transfered to any other rig. All the bones involved must share exactly the same names.

To understand the thing, try create a simple rig from scratch, parent it with a simple mesh, Shift D duplicate both object and armature and move the new obj-rig away from the original position.

create an animation of the first rig-object;
select the second rig, go to pose mode, open a dope-sheet window, in the header change the drop down menu from "dopesheet" to "action"; change the dropdown menu from "new" (2nd rig has no actions, by now) to the only one you have created.

Now, moving the timeline, both objects move together, as they share the same action and the same bone names.

Note that the action is referred to the local space of the object, so, if the 2 object have different positions, they will move as twins, in their respective position.

The same you can apply with complex models and rigs, if they share the same bone names.


How to play action actuator logic brick via python

You can use python to activate the Action actuator with this script. You will need three logic bricks: A sensor (to trigger it all), the python controller, and the action actuator.

cont = bge.logic.getCurrentController()

act = cont.actuators["Action"] # the name of the Action actuator

if cont.sensors["Keyboard"].positive: # trigger when buton pressed

    #Set all the properties you want
    act.action = "CubeAction"
    act.frameStart = 1
    act.frameEnd = 30
    act.priority = 0

    cont.activate(act) # start the actuator

You can set as many or as few of the settings that you need with python or in the logic brick, however the python will overrule any duplicate settings. Here is a list of all the settings for the Action actuator.
Do note the the two minimum setting you need are the action name, and frame end.


@FFeller ur suggestion didn't work at first, turns out i was on Vertex Select not Face Select, so it wasnt recalculating my face normals.


Video Sequence Editor - How to make subtitles?

Since Blender 2.76 (or more detailled, since the Gooseberry Branch) there is a great new Text Effect Strip feature which will do the job for you! Mikeycal Meyers already made a great Tutorial on this topic.

Just Add Shift+A an E̲ffect Strip... T̲ext. You can animate it's opacity if needed and change it's size and position.


How to add a color to a generated cube within a python script

Objects still have a color (as indicated in the documentation).
Though, bpy.ops does not return what is created or done by the ops, but the result state of the operation.
if you print(obj)in your code, you should see {'FINISHED'}.
What you can do using ops is:
import bpy

bpy.ops.mesh.primitive_cube_add()
obj = bpy.context.object
obj.color = (0,0,1,1)

Because the operation links the object to the context.
So, this work, but the color won't be rendered except in workbench rendering. It is also visible in solid view when object is selected here:

To set this color to the material, you can complete the script by the following:
import bpy

bpy.ops.mesh.primitive_cube_add()

obj = bpy.context.object

obj.color = (0,0,1,1)

# Create a material
mat = bpy.data.materials.new("Blue")

# Activate its nodes
mat.use_nodes = True

# Get the principled BSDF (created by default)
principled = mat.node_tree.nodes['Principled BSDF']

# Assign the color
principled.inputs['Base Color'].default_value = (0,0,1,1)

# Assign the material to the object
obj.data.materials.append(mat)


I'd say Musgrave texture is a good fit.
Good lighting also plays a big part.

Transmission set to 1 for clear plastic
Musgrave texture with Color Ramp to control it
Mix RGB node to adjust the colors


To extend Delagone's comment: It does not matter.

But every time you delete these keys (autokey), you're doing unnecessary work. Time which you could spend setting new key, which you need. I advise you to get used to having lots of keys around.

Another pitfall is to accidentally change the transformations later, if you have channels, which aren't keyed, you're going to loose the values you had before. Leave your additional keys in place, even if they don't seem necessary. Quite a lot animators even key all channels regardless how small the amount of channels (bones, etc) is that they changed, just so a characters pose if fixed, no matter what attributes / channels are changed later.

If the additional keys still disturb you, here is a workaround.
After moving your bones / objects to their initial transform, lock all attributes, which you don't want to key. Then create a button keying set with the channels you want to animate. Then set the active keying set, to the one you created. If you're using autokey, check the keying set button next to the autokey button.


! Going Back in Blender Project History?

You may have an autosave of when you last quit, you can check in this menu.


batFINGER had the answer I needed. Filling the circle also somehow resolved the animation problems I was having. I created a new circle just to play with the options, but I actually just filled the subdivided circle I already created.
Thanks!


Can I apply D-noise to a folder of rendered stills of an animation?

So it just turns out that if you render to stills and then use the Blender video sequencer to run those stills together into a video file you can just enable D-Noise at the bottom of the view 'Layer tab' - it slows things down a fair bit but it works a treat.


Adding texture to one side of a mesh only ( based on axis)

The Normal link in a Geometry node is dedicated for this purpose:
In the Node Editor, add the Geometry node, link the Normal to a Separate XYZ node, then use the Z link for a factor in a mix node. In my example I added a Color Ramp node to control This factor, check the image below for the nodes setup, and the Gif to see how you can use the Color Ramp node to control the effect.


Saving animation with keyframe inserting location and rotation

You can insert the new animation to the keyframe of the armature who is changed. You can actually keyframe a new rotation of just one bone of an armature, so if you modified a bone rotation in pose mode you can then press I to insert keyframe and then choose rotation, and this will insert a new keyframe for the rotation of this bone.

I attached a .blend file where two armatures are there and adjusted the bone rotation of specific bones.


Making some cloth stitches stronger than the others

In the real world, you would not close the raincoat with a single thread at the front of the neck. The edge/seam pulls the fabric together in the clothing simulation, but the single edge doesn't work well for collision detection.
The solution is to turn the edge into a face, so that real geometry exists. This face is treated as a small piece of cloth and also has the usual cloth properties like tension strength, stiffness, bending, etc. and can resist inertia better than an edge. You can adjust these settings if needed.
I tried that and it works. The next problem, however, is that when the character is in a full run, the hands, knees & feet will beat the fabric in an unnatural way and it comes to glitches. It might be better to move the cape back a bit so that nothing is in the way at the front when he runs. (That is, deform the circle into a semicircle before the simulation.)


import objects from the last frame of a rigid body simulation?

If I export it to OBJ then import into a new file, that works. Before I posted my question I had tried exporting to Alembic because I thought it was better but it didn’t do what I wanted. I guess I needed the not-better and simpler OBJ format.


The correct way to do this is to use a source and a target mesh object. Unfortunately it is not possible (well it is, but not useful in most cases) to use the source object as target.

The reason is that the original mesh data is lost when you overwrite the source. There is no way to get it back.


How do I set the origin of a mesh to the center of its axes-aligned bounding box?

No scripting required.

1) Select your whole mesh in edit mode (it may also work in object mode)

2) Change your pivot point to "Bounding box center" (little dropdown menu at the top of your 3D view)

3) Use Shift+S and select "Cursor to selected"

4) Enjoy !!!


Blender 2.8 Objects move when Export to Unity

You need to export in your T pose or your rest pose, should be found in blender on your first IK animation frame.


Mapping multi uvs textures to a character in blender? 3 separate textures for character

Using the blend file you sent :
In the UV/image editor, click image and in the menu, new image (or Alt+N)

Select the size of your image (512x512 should be enough but let's use 1024x1024), give it a name (like Full Texture) and click ok

You now have a beautiful black image. This is where we'll bake your texture.
Now go in properties panel, click on vertex data tab and click on rkuv in UV Maps. Make sure the camera icon is active on UVMap.

In 3D view, enter Edit mode with TAB, salect all with A and in the UV/Image editor, select the Full Texture", then go back in object mode (TAB in 3D view)

In properties panel, go in render tab, in Bake, bake mode click to open the menu and select "Textures"

Click the Bake button. Your Full texture is baking...

In UV/Image Editor, click Image, Save As image to save your new texture (if you don't, it'll be lost!!)

In properties panel, go to material tab, select ks material

Now go in Texture tab, click the button to change texture and select your brand new Full Texture

Back in material tab, delete all but ks materials.

Go in Vertex Data tab and delete "UVMap"

Now you have only 1 material with only 1 texture. If it doesn't show, go in material tab, enter edit mode, select all and click the "assign" button. If your texture doesn't show, go in texture tab and click the refresh button.

now save your file (change the name to keep the original with textures) and you're done !

I don't know much about sims 4 studio, but if you need an OBJ file, open the file menu, select export then wavefront (.obj). give it a name and you'll be able to import it from sims 4 studio and select the Full Texture file as texture. (the old OBJ won't work)


What do these orange lines in Object mode mean?

These are probably edges that are not part of any faces, for example if I extrude this vertex in Edit mode it creates an edge, here is what it gives in Object mode:


To duplicate the settings just add another particle system with the +, and choose the same value from the Settings combobox (ParticleSettings in your case). Note: the Seed value is not copied and will reset to 0 for some reason.
To change the name of the particle system or the settings just double-click the name and you can edit it. Note: Once you have edited the hair (Comb mode), all values become read-only, including the name of the settings.

Hair particle settngs, Blender 2.9x


Poliigon Question: What is the node setup required to overlay a Grunge Drips Overlay onto a Marble Material

In my opinion the easiest way to do it is to give your dirt picture a transparent background (and save it as PNG) so that you'll be able to use the alpha channel in the factor socket of a Mix Shader.


How to utilize the denoise passes to build a denoise node network in the compositor

Denoising Data Passes
The Denoising Data option in experimental builds and experimental render feature set currently enables some denoising passes, however they are meant to be for an animation denoising feature that is currently still being designed. They are not meant to be recombined or used for anything else then for the feature as you can see explained in the devtalk forums by Brecht Van Lommel:

It’s intended for the upcoming feature of animation denoising, where denoising happens in a post processing pass ones all the frames have been rendered. It doesn’t really have a purpose outside of that.

Removing Noise with Bilateral Blur Node using Compositing Nodes
It is however possible to remove some noise using compositing nodes.
That requires recombining the passes to the final result by adding direct and indirect, multiplying them by color and adding all of the results of this for Diffuse, Glossy, Transmission and Subsurface together. You would also need to add Emission and Environment. Color Mix Nodes can be used for this. See this image from https://en.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Passes:

To de-noise certain noisy passes you can use Bilateral Blur node. It blurs an image and uses a Determinator image to determine what edges not to blur. Basically the Determinator needs to be an image that has single solid colors or smooth gradients in the areas that need to be blurred, but if the areas differ in color and there is a sudden change on edges, they will be blurred separately and an edge between them will remain sharp. There are many ways to make this Determinator image so some testing and playing around to see what works better for your purpose will be needed, but you can add or subtract different kinds of passes to get it. Object and Material Index passes can be use for this. You can quickly give all materials and objects unique pass indices with Python:
import bpy

for i,m in enumerate(bpy.data.materials):
    m.pass_index = i
for i,o in enumerate(bpy.data.objects):
    o.pass_index = i

or you could set them manually as well.
You can sometimes use color passes as well to get good results. Normal pass is often very useful for this as well. See the documentation for Bilateral Blur node
You would also need to play around with the settings of Bilateral Blur nodes to see what works best in your case.
This would look something like this if done for indirect Glossy and Diffuse passes that happen to be the noisiest in my example scene:

Sometimes Direct passes may be noisy as well - you should see what the case is in your scenes.


Why Is my rendered image a white silhouette?

It's because of your compositing nodes :

Basically, your nodes are doing the following :

Take the rendered image, blur it, 100% mix with white and done.

I'm not sure of what you tried to do, may just remove the mix node and blur node.


Is there a way to add hair texture to 2d?

Yes, you can add a texture of hair exactly the same way you add any other textures for shaders for the rendering engine you use.

Will it look hyper-realistic or realistic or even good? Most likely no. Hair is visible outside the surface and because of that in most situations making hair in CG requires some sort of structure. There are many ways to create hair in Blender: hair particles could be used in multiple different ways or you could also use geometry with transparent textures, in some specific situations displacement or sculpting combined with texturing may work.


Any Python code examples of bmesh operations on multiple objects?

This is an example based upon batFINGER's link that uses a vertex index.

import bpy
import bmesh

context = bpy.context
mesh_obs = [o for o in context.selected_objects if o.type == 'MESH']
bm = bmesh.new()

for ob in mesh_obs:
    me = ob.data
    bm.from_mesh(me)

    bm.verts.ensure_lookup_table()
    bm.verts.remove(bm.verts[0])

    bm.to_mesh(me)
    me.update()
    bm.clear()


How to Automatically copy keyframe from one object to other with one step

ok, here is a python solution:
result looks like this: https://youtu.be/HsVNCyuWyDY
what you have to do:
Create a collection with the name "Automatic_frame_visibility" and put all your objects in there.
After running the script and starting your animation, each object will be visible in the order of the collection with one frame visibility.

python script:
import bpy

def frame_handler(scene, depsgraph):
    counter = 0

    for eachObject in list:
        if scene.frame_current - 1 == counter:
            eachObject.hide_render = False
            eachObject.hide_viewport = False
        else:
            eachObject.hide_render = True
            eachObject.hide_viewport = True
        counter += 1

print ("-------- Script started")

bpy.app.handlers.frame_change_pre.clear()
bpy.app.handlers.frame_change_pre.append(frame_handler)

list = []

for eachObject in bpy.data.collections['Automatic_frame_visibility'].objects:
   list.append(eachObject)


I found this code sample (originally from the Blender wiki) to be very helpful in understanding file browser usage. Specifically, look at the "execute" method of the ScanFileOperator class, which passes self.filepath (the chosen file) to another function (scanFile):
#
#   Opens a file select dialog and starts scanning the selected file.
#
class ScanFileOperator(bpy.types.Operator):
    bl_idname = "error.scan_file"
    bl_label = "Scan file for return"
    filepath = bpy.props.StringProperty(subtype="FILE_PATH")

    def execute(self, context):
        scanFile(self.filepath)
        return {'FINISHED'}

    def invoke(self, context, event):
        context.window_manager.fileselect_add(self)
        return {'RUNNING_MODAL'}


Controlling particle size via texture with particle physics disabled?

You don't have to use the Type 'Emitter', choose 'Hair' instead, where the particles rest on their places.
I assume you regulated the size of the particles like it is described here
Is it possible to use a texture to control the size of particles?
I tried it and it worked (I used a Marble-texture). Here is the screenshot:


Looking at that screenshot, I think that the bevelled edges are crossing over each other. This is often caused when trying to bevel sharp edges that are in close proximity. You may have to manually delete the local geometry, use the knife tool ("K" in edit mode) to cut in new geometry and fill in the new faces.


The fluid is disappearing because the domain object is not "baked" completely. It's baked only until the frame where it's disappearing. Remember, the fluid is simulated on the domain object, so up until the frame, it's a fluid, and then it "turns back" into the domain object.

You need to bake the domain object and wait for that to finish before rendering.


Pageturn: Duplicate animated objects with time offset (Animation Nodes)

I've done a similar thing using shape keys instead of animation keyframes.  Then you can duplicate the object, and build logic to animate the shape keys differentially per object and get time offset programmatically.

In my case, I had a crowd of robots walking and I wanted them to walk at different paces and different parts of the walk cycle.


When dragging a mesh onto a rig, the rigging menu with "with automatic weights" option won't appear

Did you try to apply the rigging in edit mode or object mode? The rig with automatic weights only works correctly in pose mode. Also, you can not select "with automatic weights" in object or edit mode by going to the object tab, because it will not parent the bones correctly. I make this mistake often.


Problen with Object not appearing in render

The grey Background with the grid means, there is no Image to preview. You did not actually start a Render. You can start a Render in the Header via Render > Render Image or by hitting F12.

You probably used View Render or F11, wich displays the last Render (in this Case None).


Glossy Shader not working to create realistic texture as I wanted it too

To get a nice reflection you'll want to add

More light
Materials, especially glossy or refractive materials, are hugely dependent on the surrounding light sources. Try adding a nice big mesh light (or area lamp) for the material to reflect
Fresnel
Light tends to reflect off of materials more at glancing angles, and reflect less when hitting a surface straight on. If you look at your top-down reference picture/texture, there is hardly any visible specular reflection ("specular" refers to perfect or mirror-like reflections, such as the sharp white highlights)

To simulate this, add a Fresnel node, plug your bump/normal map into it, and connect it to the Mix factor of the mix node which is mixing in your glossy shader.

This will make a big difference, especially on surfaces with lots of small variations in angle.

In this example I slightly complicated things by giving the rind a lower IOR than the rest. A more simple setup could just connect one of the fresnel nodes straight to the mix shader (both selected). However given that the rind and fruity parts of the orange have quite different optical properties, you probably do want to simulate that in some way.

Note that an actual orange is quite complex, with the fruity parts being translucent with a visible internal structure. To properly simulate one, you might want to model the slices and rind separately and use a translucency, SSS or volume shader (somewhat similarly to this).


Select the object to unwrap, and while in edit mode press  U  to unwrap. Then, select the image you want to UV map to your objects from the list of available images (if more than one has been added to your scene), while in the UV/ image editor. Repeat for your other objects. In the attached gif, I just used a stack of cubes for simplicity, but the method should work in any case.


How to install Blender while retaining addons

New Blender versions can be installed along side the previous versions, meaning that your old install of Blender will continue to work with its add-ons.

For the new version of Blender you will have to install the add-ons again. If the add-on you've previously downloaded / purchased is compatible with the new version of Blender, you can use the same files (.zip, .py) for the installation of the add-on. Should they not be compatible, then you will have to check if an updated version of the add-on is available for that specific Blender version.

Add-ons for 2.79b and earlier can't be used in Blender 2.8x because of the changed API.


Two things that jumped out to me.
First, the noise texture has a Detail slider.  This increases computation somewhat.

The second thing is messing with the settings in Render Properties -> Volumes.  Try decreasing the Viewport and Render Step Rate and possibly increase the number of Max Steps.
This may not be necessary depending on your scene, I think it mostly helps with large volume objects but clouds are typically pretty large.  This will unfortunately make volumes take a long time to render.  That's the cost of accuracy.

Just for reference, even on this default cube sized volume you can see we run into some strange effects on the top boundary with the default volume settings.  These images were both 512 samples in Cycles, no denoising.


Ok, I found this video from the same guy:
https://www.youtube.com/watch?v=kZD8sSX7NtU
It uses booleans to cut out doors and windows. Seems to work for the above. Haven't tried it yet for slanted walls, but here's hoping it will do.
I was reluctant to use booleans first because they seemed so buggy. May not be buggy, just very hard to use whenever something is a little off. In my case, turned out one of my normals was pointing inwards and that was confusing everything.


image rendered in blender differs from image saved to disk

Strangely enough it appears to work if you convert to premultiplied alpha:

This messes up the RGB values in blender, but the exported png then works as desired.
I'm not too sure why this works the way it does (I'd expect the opposite), but a lot of alpha handling in blender is rather odd..


It was a driver problem. The affected computer model is from the ASUS UX410 series. The Intel update refuses to install the new driver and refers to a customized driver from the manufacturer. However, the automatic update function of the manufacturer does not find the new Intel driver, but it is listed on the manufacturer's website.

I installed the driver and the problem was fixed. There are no artifacts in the viewport now and the render is clean.


make a hotkey to determine the orientation and the pivot point?

Well, the 3D cursor really has no orientation...but orientation for any kind of transform already exists as local, normal, global and screen....they can be found at the bottom of the viewport near where you found the pivot point options(median point, cursor, individual objects, bounding box etc...)

but technically you can set a hotkey for the transform orientations in the user prefferences...they are already defined and you can see them merely by hovering over them with the mouse.


How do I change the mouse sensitivity for orbiting?

This has finally been resolved in the latest builds of 2.81 (tested with 2.81-0812949bbc3d-windows64). There is now an option in Preferences > Navigation > Orbit&Pan > Orbit Sensitivity to adjust viewport orbit speed. It appears that the default speed has been reduced as well (checked against 2.8)


Get the active/current clip in Motion Tracking tab

It seems bpy.context.edit_movieclip is doing that I was looking for.


How do I generate random cylinders, with random height on a predefined area?

Test run, settings as posted Placed 66 of 68

Algorithm for random distribution of circles in a square

  This simple script to place a number of num_circles circles with
  radius radius in a refined rectangle (aligned to global axes) speficied
  by xmin, xmax, ymin and ymax by trying random locations until it not
  colliding with an existing circle. This is certainly not the most
  efficient way of doing it, but it should be fine for smaller problems
  and if the relative area covered is not too high.

Test code after making a couple of edits to https://blender.stackexchange.com/a/89658/15543 to make it add cylinders of random height to a rectangle.

from mathutils import Vector, Matrix
from mathutils.noise import random, seed_set
import bpy

# Specify parameters
seed = 0
xmin = -10
xmax = 10
ymin = -10
ymax = 10
radius = 1
num_circles = 68
max_tries = 10000
max_height = 4
# Init
seed_set(seed)
sx = xmax - xmin - 2 * radius
sy = ymax - ymin - 2 * radius
xminm = xmin + radius
yminm = ymin + radius
existing_locations = []
sce = bpy.context.scene
bpy.ops.mesh.primitive_cylinder_add(
    location=(0, 0, 0),
    depth=1,
    radius=radius)
ref_circle = bpy.context.object
ref_circle.data.transform(Matrix.Translation((0, 0, 0.5)))

# Loop
for i in range(num_circles):
    j = 0
    searchOn = True
    while searchOn:
        if j > max_tries:
            print("Placed", i, "of", num_circles)
            bpy.ops.object.select_all(action='DESELECT')
            ref_circle.select_set(True)
            bpy.ops.object.delete()
            raise ValueError('Found no more room for another circle')
            break
        j += 1
        new_location = (xminm + random() * sx,
                        yminm + random() * sy,
                        0)
        for existing_location in existing_locations:
            if (Vector(existing_location) - Vector(new_location)).length < 2 * radius:
                break
        else:
            new_circle = ref_circle.copy()
            new_circle.dimensions.z = max_height * random()
            new_circle.location = new_location
            sce.collection.objects.link(new_circle)
            existing_locations.append(new_location)
            searchOn = False

ref_circle.select_set(True)
bpy.ops.object.delete()
context.view_layer.update()


No sure why the driver does not update in the cube but does on the text object. This does not seem to be an Animation Nodes bug. It's more likely a dependency graph problem of Blender.

What you can do is to control the transparency of the material directly by using active_material.alpha as path in the Object Attribute Output node.


Turnarounds are generally made leaving the character still, and having the camera orbiting: this can be achieved creating an empty in the center of the orbit, parenting the camera to the empty and rotating the empty: you will have to set at frame 1 a rot keyframe value of 0, then set at frame 37 a Z rotation of 360 (Euler rotation), then go to graph editor, select all keyframes, press T and set the interpolation to "linear" and run the animation from 1 to 36.

If you really want to rotate the character, as it is posed, every movement has to be performed by the armature in pose mode, do not rotate the mesh in object mode, because the character is child of the armature, not the inverse. If it is not present, you will have to create a "Main" bone and set all others bones child of the main, eventually parenting all tools and platform to it, then animate the rotation of the main bone.


How can I move bunch of vertices to the origin of the world properly with Sverchok?

List Math average isn't what I would use to find the average vector, we have an analyzer node for that. It expects inputs of Vertices, and employs an appropriate algorithm for that kind of input.

List Math expects primarily lists of numbers, (signified by the type of socket : green ) tweaking the level parameter will not result in returning the average of vectors. This is an understandably confusing situation.


After I converted Constraint to F-curve it start to simulate.
Why it is not working like in tutorial from 2020 ... hm ... a bug?


Blender 2.8 subdivision creating small bumps

The cause of this most likely is because of overlapping faces or your normals are on the wrong side. Meaning that the physical plane of your mesh is on the inside of your mesh and building it around that somewhere caused overlapping faces. You can see if your normals are on the wrong side by going into the material viewer on the right side of the view port render shading option, which is the down button next to the transparent globe and view the backface culling status there by checking the backface culling option.


Total newby question - How to either close the rendering window or return to the main scene window?

Just press Escape, with your mouse cursor over the area.

Or, you can change the Editor with the icon bottom left the area (I guess "3d view" is the editor you're looking for)


No there isn't a way to render a frame randomly - built-into Blender,
although it wouldn't be so hard to write this as a Python script.

However using no-overwrite with an online file-system seems like asking for troubles, in this case its probably worth looking into some kind of render-farm software.

If you know the total number of computers beforehand, you could give each its own frame-offset from the start and use a frame step, so they're not going to re-write each-others files.

See the --frame-jump and --frame-start option, to offset relative to the frame start.
 https://www.blender.org/manual/advanced/command_line.html#command-line-arguments


How can I convert Grease Pencil's 'Build' modifier to keyframes?

You can divide the various strokes into layers, then add more than a build modifier, targeting each one to a single layer. Then every build modifier can be set to start at one certain frame and last for any number of frames.


You can mirror your object along its pivot point by pressing , then CTRL+M and in this case pressing X to mirror along X axis.

It appears that the problem was due to a rigidbody on the piece interfering with transform operations.

Your rotation and scale are unapplied, be aware that modelling on a non uniformly scaled object will cause problems.


boolean slice no longer part of blender 2.8?

It's using the Bool Tool Plugin

The tools belong to the Bool Tool plugin. They do not come with the vanilla B 2.80, you'll have to install a compatible version of the plugin.

You can find it here:
https://gist.github.com/derappelt/603883d70a56c5d1f5080c2980bb5b9f

Then you should look for the Object menu, at the bottom you'll find the BoolTool operators you were looking for:


As said in the comments, mirror modifier has to be 1st in the list (up), if it's not, click on the up arrow at the upper right corner of the mirror modifier. Be sure to check "merge" and "clipping" options.

If the problem still appears, edit your mesh, select all vertices that should be in the center. Scale them to zero (align) on the X axis (S X 0), then move them on X axis to make them stick (G X -move mouse-) repeat this on the other X direction (G X -move mouse to the other direction-). All center vertices should now be in the center, clipped and merged and will move with the armature as they should.


Where is the Bake button in blender 2.9 (Fluid simulation)

Set the cache type from "Replay" to "Modular". Replay will simulate the fluid when you play the animation so it's good for previews, Modular will actually bake it onto the disk.


This can be accomplished by using proportional editing.

Add a cube.

Switch to edit mode (Tab) and subdivide it (F3 > Subdivide). Use an odd number of subdivisions in order to have a single vertex at the center of the cube face. Use a low number of subdivisions, e.g. 5.

Select that single vertex at the center and enable proportional editing (O) and set the falloff type to Sphere.

Move the vertex down on the z-axis (G + Z). If you're not using the default dimensions of the cube you may have to adjust the radius using the scroll wheel of your mouse. The outer edges of the cube shouldn't be within the radius of the proportional editing.


Issue or Bug. The shading of an object changes when deselected in "Smooth" mode. (Why Radeon Users May Want to Avoid Ubuntu 16.04)

If Blender 3D is running fine on your Linux distro and your considering about upgrading to the latest Linux distro (in my situation to Ubuntu 16.04).

First check if they have released new drivers or if there even are drivers that support your upgrade.

Especially for AMD/ATI/Readon Graphic cards, you may want to stick to your current OS version.

They have stopped working on new drivers for AMD Ubuntu 16.04,

Link: http://www.omgubuntu.co.uk/2016/03/ubuntu-drops-amd-catalyst-fglrx-driver-16-04

Also useful

Link: https://askubuntu.com/questions/744050/im-using-ubuntu-16-04-and-theres-no-fglrx

Link: https://wiki.ubuntu.com/XenialXerus/ReleaseNotes#fglrx

UPDATE 31-05-2016

Some interesting new developments: AMD's gaming-optimized AMDGPU-PRO driver for Linux is in beta.

Link: http://www.pcworld.com/article/3075837/linux/amds-gaming-optimized-amdgpu-pro-driver-for-linux-is-in-beta.html

Still in Beta and won't support GPUs older/lower than the Radeon HD 7000 series.

Ubuntu still recommends sticking with Ubuntu 14.04.


I am not sure about material action support in unity, however I am pretty sure you can use a UV animation,

Just move the lights face to a copy of the face lit up?

http://answers.unity3d.com/questions/19848/making-textures-scroll-animate-textures.html

This way you just need the 'lit up' texture face in the uv sheet for each color.


Your project has materials for the cycles render engine. If you render on blender internal the file will not render correctly.

Materials form different render engines are not interchangeable.


How can I make Blender put less strain on my CPU?

If 90% of CPU load bothers you, ie its not comfortable to work with other programs, you can set priority to the Blender by Task Manager.

Press Ctrl+Shift+Esc to launch Task Manager.

Prior Windows 10, right click on Blender process->Set Priority->Low. In the Windows 10 select details tab, and again right click on Blender process->Set Priority->Low


Those are not colored shadows, shadows don't have a color per-se, they are just e slightly colored light sources.

Just add a slight tint to your lamp objects so one has a warmer redish tone, and the other has a cooler tone towards blueish or green.

This is generally done using a Three Point Light system, which is a well know lighting technique in photography also.

Optionally if you want more realistic shadows or natural lighting use a sphericall environment map in your scene's World nodes, Ideally HDR based or as regular JPG image.


Why can't I extrude a Nurbs curve along a nurbs path

By saying extrude along a path, are you referring to 'Skinning'? If so, they have to be separate objects, then you use one as a 'Bevel' object to skin(bevel) the path. If you could post a screen shot and clarify this, it would help.


This may be standard practice but it works for me so I wanted to post it here. It seems that Blender looks at the render layer settings when baking.  I have a bunch of detail in my file (wall framing, interior trim, furniture etc.) that doesn't effect the baked texture on, for instance, exterior walls.

so when I bake the exterior wall texture I exclude those items in the render layer panel.  This seems to have eliminated the crashing problem. It's just important to be sure that none of the excluded layers would have contributed to the bake.  In this case the exterior lighting casts shadow on the walls so that layer isn't excluded.  There may be better ways of handling this but this is what I have found that works for me.


Grey blank screen when animation is rendered

Iam also new to Blender,

but I guess that you not switch to the Cameraview, press the little CameraIcon on the right
or  0 on the numpad

http://builder.openhmd.net/blender-hmd-viewport-temp/editors/3dview/navigate/camera_view.html


I gave it a try:

Start with a Bezier Circle (Add > Curve > Circle)
Add a cube and change the x-dimension to 2 * pi. You can calculate directly in the input field and you can use constants like pi. It should be 6.28 m and so it fits the circumference.
In Edit Mode gave the cube some additional loop cuts with CTRL+R. Scale the cube to your liking, but keep the x-dimension. In scale-mode press Shift-x to lock scaling on that axis. Delete the end faces. It should look like this:
Edit: Make even more subdivisions ;)
Add a Simple-Deform-Modifier. Set it's mode to Twist, the Axis to X and the Angle to 360°
Add a Curve-Modifier. Due to our calculation it fits perfectly.
To animate the twisting you can animate the cubes x-rotation
For Texturing unwrap your cube and place your stripes on the text created in an image editor of your choice.
You can animate the texture later. Therefore you can rotate every second stripe around 180° to let them move in opposite directions.
To animate the texture set up your material and animate the x-location.

Hope that helps! ;)


Try using a Sharpen filter in the compositor:


How to color code strips in blender VSE?

The following code creates a color strip of the same length as the selection, puts it in channel 1 and creates a metastrip. It's a bare code with no checks of whatever. Hope this can get you on the way.
To test the code: open the scripting workspace and create a new text block. Copy the code in the text block. Select 1 or more clips in the video sequencer and run the code.
import bpy

sel_strips= bpy.context.selected_sequences

first_frame = 9999
last_frame = 0

#calculate first and last frame of selected strips to set the length of the color strip
for strip in sel_strips:
    if strip.frame_final_start < first_frame:
        first_frame = strip.frame_final_start
    if strip.frame_final_end > last_frame:
        last_frame = strip.frame_final_end

#the color strip is always put in channel 1; no check for replace or whatever
color_strip = bpy.context.scene.sequence_editor.sequences.new_effect(name='test', type='COLOR', frame_start=first_frame, frame_end=last_frame, channel=1)
#the color is set to red
color_strip.color = (1,0,0)

#this operator creates the metastrip
bpy.ops.sequencer.meta_make()


How can I invert any key frames to start the animation from the last key frame?

Set your marker right in the middle of your frames (e.g. if you have 500 frames, set it on 250), mark all keyframes, then right click and then choose
mirror by times over current frame


Another easy thing you can do to temporarily simplify your logic editor is unchecking the Link check box

This logic mess may seem a bit overwhelming

Simply un-checking the Link box can Significantly simplify your workspace, at least long enough to figure out what you were trying to do.

 When you have wires connecting bricks across multiple objects, and especially when you have scroll bars and hundreds of wires between your bricks, you can sometimes forget what you were trying to do before you find the right sensor or actuator.


EEVEE ignores light-emission outside of the camera frame

Eevee is not a physically accurate render engine and employs a number of 'shortcuts' in order to get realistic results with minimal render time. One of these shortcuts is Screen Space Reflections (and Refractions).

As implied by the name, Screen Space interactions are dependent on what is visible on the "screen" (effectively the camera) so anything outside the visible field of view will not be considered. This is a method typically employed in game render engines and is usually 'good enough' but does have its limitations. By not considering anything in the scene which is not directly visible the rendered can significantly reduce the workload but in your case it produces such unrealistic results. For Viewport renders the same is true but the viewport can "see" parts of the scene outside the frame of the camera so the effect seems less pronounced (but if you adjust the view towards the edge of the visible space you should see the same effect).

If you want to continue using Eevee (rather than swap to Cycles) you have two options.

Render each frame larger than required and then trim off the excess in the Compositor. Resizing the camera to include a border without affecting the rest of the frame can be easily achieved by adjusting the Sensor Size of the camera (in the Camera properties) and the compositor can be used to trim back down the the required size.
Use Light Probes. Light Probes are effectively meshes that act as a boundary between your objects and capture details of the light crossing that boundary. The Light Probe includes settings as to the area of effect to consider for reflections/refractions. The light is captured by 'Baking' the light map - options for which are on the render settings under the heading 'Indirect Lighting'. Once the lightmap is baked it will be used for reflections regardless of whether the source is inside or outside the rendered 'screen space'.


Particle System is floating in the air and not on the surface

The reason why your grass is not where it should be is that the object's origin is way off from the mesh, -30.5 m in X direction, 3.1 m in Y direction and 0.4 m in Z direction. That's the reason why they are not close to the surface or sometimes sinking in, because they are "growing" more than 30 m away from where they are "born".

To get them distributed correctly you should set the origin close to the bottom of the grass mesh (image below). One way to do it: go to Edit Mode, select the bottom vertices of the grass, Shift+S > Cursor to Selected. Then back into Object Mode, right-click on the grass object, Set Origin > Origin to 3D Cursor.


Try the following:

Close Blender
Rename C:\Users\YourNameHere\AppData\Roaming\Blender
Foundation\Blender\2.79 to
C:\Users\YourNameHere\AppData\Roaming\Blender
Foundation\Blender\2.79.bak
Use your login in Windows instead of YourNameHere and your version
of Blender instead of 2.79
Start Blender again


The issue is not with the driver per-se, but with Windows.

The operating system has a builtin timer for when the graphics card is busy. If the graphics card doesn't respond for more than a certain period it activates a count down. When exceeded it terminates the graphics drivers process to regain system responsiveness.

As Julian Herzog writes

  The problem here is that Windows has a timeout detection and recovery
  (TDR) system that detects if a GPU computation takes longer than a
  given amount of time, the default value for that being two seconds,
  and then “reinitializes” the Windows Display Driver Model (WDDM)
  driver and resets the GPU. This will stop the rendering process. You
  will also notice that any displays attached to the GPU you use for
  rendering will turn black for a short moment.

  Normally, this system is great because it prevents permanent screen
  freezes for malfunctioning drivers or games. But in Cycles, one sample
  is considered one computation, which means that if your sample
  calculation takes longer than two seconds, Cycles (and the Blender UI,
  if you render with UI) will crash.

To prevent this you must change a key in Windows registry

Open the registry editor (REGEDIT)
Got to HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Control/GraphicsDrivers
Set the TdrDelay DWORD
If it contains a kyword named TdrDelay edit its value
If there is no TdrDelay right-click into the empty space below the
values
Create a new “DWORD-Value". A DWORD (32-bit) -Values hould cut it
Set its name it “TdrDelay”
Change the value to 8 or 16 (value is interpreted in seconds)
Beware of the editing mode, make sure you save as decimal value, not hexadecimal (I found only 512 was enough to prevent most crashes).
Reboot your system for the changes to take effect.


I'm assuming you're using a build off of Graphical.org? Apparaently the anti-aliasing is a reported bug in those versiosn as they don't fully support the nvidia chipset yet.

For more read here: https://developer.blender.org/T48544


how to set camera's look-at point when moves along a curve?

You can access and alter the properties of the constraints of an object, all constraints are listed in object.constraints, access each constraint by its name or type and of course the index

cam = scene.camera
# if you are sure the constraint exist and has the default name
fol_path = cam.constraints['Follow Path']

fol_path.forward_axis = 'TRACK_NEGATIVE_Z'
fol_path.up_axis = 'UP_Y'

# to avoid errors in case it doesn't exist or has another name
for cons in cam.constraints :
    if cons.type == 'FOLLOW_PATH':
        cons.forward_axis = 'TRACK_NEGATIVE_Z'
        cons.up_axis = 'UP_Y'


We at GarageFarm.NET support Blender 2.8 projects over at the farm. You can download and install our scene preparation plugin from your web dashboard after registering, and enable it on your preferences tab in Blender. It will be listed with "update to 2.8x required" but you will be able to enable it. You can register here and get free $50 worth of credits.

Feel free to reach out to our support team as well! They are available 24/7 via our chat application (hit the chat icon on the page).

We acknowledge that 2.8 is still in BETA, and so there's no guarantee you won't run into problems, but our wranglers will be there to assist you whenever you need them, and we've rendered some 2.8 projects successfully already.

Cheers!


How to have a clean flat surface after boolean modifier for adding materials

You can select some or all faces, then X > Limited Dissolve, to make ngons, so that flat surfaces will get merged/simplified.

Additional options such as Max Angle can be set by pressing F6.


The ~.blend file you wish to import must first include a group, which you create in your original project file, by any of the normal means of creating a group: selecting the elements you want in the group, and selecting the menu item Object > Group > Make Group when the viewport is in object mode, or using the defined shortcut key for this, CTRL-G, or alternatively by using the "add to Group" options under the Group pane in the "object properties" tab of the properties editor. If a group is defined in the file you are wanting to append or link from, when you select the append or link option in the files menu, after selecting the file, you will see in the list of items you can append or link, a listing for "group". Select this, and select the desired group, just as you would another data type, e.g., object, mesh, or material.


Physics have a start and end cycle, there is no way to "reset" the cycle once it starts calculating. My goal was set based on a limited knowledge of how the physics work. The best way to go about my goal of making a looping gif, with the wool moving, is to add extra bones and weight the wool to the bones, and animate it manually.

Alternatively, if the pose/animation allows for it, when creating the gif, reuse the images in reverse for the second half, to make the illusion that the wool is going back into place. This doesn't work for some animations, but it'll work for a basic standing position at least.


Never mind
I found the solution
You just have to set the Alpha Blend to Alpha Clip in the Material Options.


For something like this you should probably be using a cage object. Normal baking gets a little wonky when it comes to sharp edges. To make the cage duplicate the low poly object and then scale it up slightly using Alt + S to scale along the normals. In the Bake settings check the Cage box and select the cage object.


How to do what this person did in this video tutorial?

He selected the Lamp Object, and then went to the data panel.

As for your materials, one of your swatches is completely alpha (The current one in your screenshot).
Select it, click the Color swatch, and take the "A:" value all the way to 1.

Then match the positions on the ramp that the video has.


rotation is reset when I playback animation

Looking at the image above., the animation is recorded on the Empty. I assume but cannot tell for certain that all 3 rotations are animated. you only need a single rotation to be animated.

You can remove the other 2 keyframes from the axis you don't need to be animated and it will fix the issue.

The yellow color means that there are keyframes present for these properties.
You should remove them. For example I assume that the rotation around the X-axis is the one you want to keep.

Press other mouse button on the Y and click on Clear Single Keyframes. Do the same for the Z.

This will remove the keyframed animation on the Y-rotation and the Z-rotation.


How to make object A a parent(keep_transform) of object B via Blender's Python API?

If you want to retain the transformation of the child you can do this:

 b.parent = a
 b.matrix_parent_inverse = a.matrix_world.inverted()

You need to update depsgraph after creating the empty (matrix_world of the newly created object is updated after updating depsgraph):

import bpy # sin esta libreria no funcionan los comandos en blender
techos = bpy.context.selected_objects

for i in techos:
    #bpy.ops.object.empty_add(type='PLAIN_AXES',radius=100,location = i.location) = o

    empty = bpy.data.objects.new( "empty", None )#crea un empty y lo guarda en una variable
    bpy.context.scene.collection.objects.link(empty)#agrega el empty a la escena
    empty.empty_display_size = 3 #da un tamaño al empty
    empty.empty_display_type = 'PLAIN_AXES'#determina la forma del empty
    empty.location = i.location #la locacion del empty es la misma que la del objeto seleccionado

    # Add this line
    bpy.context.evaluated_depsgraph_get().update()

    i.parent = empty#el objeto seleccionado es hijo del empty
    i.matrix_parent_inverse = empty.matrix_world.inverted()

    #i.parent_set(i,keep_transform = True)
    #i.parent_set()
    print(empty)


Preview and render use different render engines, that's why it looks different.
Just enable refraction in Eevee and both will look right.

Properties > Material > Viewport Display
Check Screen space refraction
Specify Refraction depth (glass thickness)

More thorough answer: My glass material isn't transparent in Eevee


Kudos to MrZak:
Q1 is solved if you just press "Apply Base" in the Multires Modifier.

Q2 I am not 100% sure but the stray vertices stemmed from a messy quad structure inside the mouth. After I cleaned that up they were gone.


How to execute my operator (wikibooks.org 2020)?

The code works just as it is supposed to work. You just need to enable Operator Search to use it. You need to select Edit -> Preferences. Under Interface check Developer Extras checkbox.

Now you can find Operator Search from Edit drop down menu.

Search Add Tetrahedron

Errors
You can select Window -> Toggle System Console to see the errors your code gives.


Detect if object data is associated with a scene in any way

I looked at Blender's source code and realised it was quite an ordeal for the dopesheet to filter objects relevant to a context, so I gave up any hope of a simple solution and just went about doing a ersatz version of it in python.

It's a bit of a mess, but it works for detecting most non-objects (and objects) with animation data in a context:

https://gist.github.com/hedgehog90/634ea03acd2a1d87f99fbb06857e1956


Turn your bitmap image to a svg with Inkscape or Illustrator (see a tutorial on bitmap tracing, it's very easy). If you don't know .svg is a standard format for vector images, which will allow blender to interpret the image as curves.
Import svg in blender, convert to mesh, add a solidify modifier (in the modifier turn ON "On Cage" and delete all vertices that behave weirdly if you have any, make sure you don't accidently delete faces)
Make a circle with Shift+A, subdivide it 4 or 5 times, add a Boolean modifier targeting your imported svg and you should get this

Here is the .blend file:


change the global variable value from function in bge?

This is, no kidding, straight from my professors mouth.

There are three scopes of Variables; one does not apply to blender.

Local
Form-Level
Global

Local variables would be like game properties, or a material.
They have effect on only those procedures and functions who posses them and objects/procedures designed to be affected by them via collision, near, ray, radar ect.

They can only be changed/accessed via the procedures/functions to which they belong.

Global variables (this is the real answer) can be changed, accessed, and modified by any/all procedures, functions, and objects.

This means Yes. If it is on one, it's on 'em all.


2.8 is missing the Carve option in the Boolean Modifier

As mentioned here, by developer Sergey Sharybin, 'Carve' was removed in favour of focusing on one boolean implementation (BMesh):

  We've got quite comprehensive BMesh based implementation, which is way
  easier for maintenance than abandoned Carve library.

  After all the time BMesh implementation was working on the same level
  of limitations about manifold meshes and touching edges than Carve. Is
  better to focus on maintaining one boolean implementation now.

A task remains open to track any issues with the BMesh implementation:

https://developer.blender.org/T47030

There is also a fairly brief discussion on devtalk.blender.org regarding this topic (there may be other discussions - I just found this link quickly) which includes a few comments from a developer who is working on the BMesh library:

https://devtalk.blender.org/t/carve-was-the-only-boolean-mode-that-worked-for-sculpting-and-it-got-removed-in-2-8-wtf/5576


Is possible to transform a mesh into a texture? In 3DS max this is called "Render to Texture

It called baking in Blender, you can find it in the render tab:

https://docs.blender.org/manual/en/latest/render/blender_render/bake.html

https://docs.blender.org/manual/en/latest/render/cycles/baking.html


Blender 2.8 3D viewer export with texture

Make sure you save your texture into the folder where your fbx file is.

In the image I am in UV Editing


physics : blow sheets of paper with wind?

It depends in how many sheets you'll have in your scene, and what type of animation you want to do.

If it's a realistic animation, then I'll prefer physics and work on my simulation enough to bake it (it wont be that heavy then)

If it's a cartoonish animation with few sheets, then the curve method could be fun, but it's not the fast option here.

Curious to see what others think about it !