text:
Copy existing property from e.g. Properties window to a custom panel
So if I have this custom panel in the 3D view, is there a way I can take a property from for example the properties window and paste it onto my panel below the "text" prop, without creating a new property?
The reason I do not want to create a new property is because I want them to share all data, such as values, keyframes, drivers etc.

    bl_info = {
    "name": "",
    "description": "",
    "author": "",
    "version": (0, 0, 1),
    "blender": (2, 70, 0),
    "location": "",
    "warning": "",
    "wiki_url": "",
    "tracker_url": "",
    "category": ""
}

import bpy

from bpy.props import (StringProperty,
                       BoolProperty,
                       IntProperty,
                       FloatProperty,
                       FloatVectorProperty,
                       EnumProperty,
                       PointerProperty,
                       )
from bpy.types import (Panel,
                       Operator,
                       AddonPreferences,
                       PropertyGroup,
                       )

class inouse_Settings(PropertyGroup):

    my_bool = BoolProperty(
        name="Enable or Disable",
        description="A bool property",
        default = False)

class UV_OT_my_panel(Panel):
    bl_space_type = 'VIEW_3D'
    bl_idname = "UV_OT_my_panel"
    bl_label = "Custom"
    bl_category = "Custom"
    bl_region_type = 'TOOLS'

    def draw(self, context):

        scn = context.scene
        mytool = scn.inhouse
        layout = self.layout

        col = layout.column(align=True)
        row = col.row(align = True)
        row.prop(mytool, "my_bool", text="Text")

def register():
    bpy.utils.register_module(__name__)
    bpy.types.Scene.inhouse = PointerProperty(type=inouse_Settings)

def unregister():
    bpy.utils.unregister_module(__name__)
    del bpy.types.Scene.inhouse

if __name__ == "__main__":
    register()

Of course, you can re-use all python properties at least.
Enable Developer Extras, 'Right-Click' the property and choose Edit Source, this will open up the associated .py file in the Text Editor:

'Resolution' adapted:
def draw(self, context):
    scn = context.scene
    rd = scn.render

    layout = self.layout
    row = layout.row()
    sub = row.column(align=True)
    sub.label(text="Resolution:")
    sub.prop(rd, "resolution_x", text="X")
    sub.prop(rd, "resolution_y", text="Y")
    sub.prop(rd, "resolution_percentage", text="")


text:
Image Alpha Background Renders Black when using "Import Images as Planes"
I must be missing something here.  I'm doing an extremely simple Import Image as Plane using the AddOn and the imported image has an alpha background but it renders (and even previews in the material preview) as black where the alpha background should be.
When I import, I select Emission & Transparent so the material setup is automatic.  I've read similar issues but people are typically missing the transparent node and connecting the Alpha channel from the image into the Mix Node factor.  But this is all here.
I must be missing something really stupid but I've wasted so much time trying to fix this thing.  Any help would be greatly appreciated.
Not sure if it matters but I'm using 2.74 RC2.
Many thanks!
I created this dummy blend file to test outside my project but problem still exists.  Here is the simple .blend file: AlphaTest

source: Stack Exchange

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/

sort: votes


text:
Closing useless areas with python
I want to close all useless areas in my blender window. How command I could use?
To sum up, I need the command of "Close area":
for area in bpy.context.screen.areas:
    if area.type != 'IMAGE_EDITOR':
        #Close area

Why you can't use: CTRL + UP? ...only to understand the issue :)

Well, because Blender isn't open. I'm using python in gedit, so, to do any change, I need to code what I want. After code, I run my script, and it creates a blender file with my specifications.

Related: http://blenderartists.org/forum/showthread.php?308653-Tutorial-as-a-Python-Script (posts #4 and #12)

If you're using Blender's default startup.blend as your initial starting place, the easier solution would be to change to the "3D View Full screen" layout and then change that area to hold the editor you want (in your case, the UV/Image Editor). The code might look something like this:
bpy.context.window.screen = bpy.data.screens['3D View Full']
bpy.context.screen.areas[0].type = 'IMAGE_EDITOR'

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/3.0/


text:
Game Engine's bad visualization with layers
I'm using a score layer above a game layer.
The score layer is a Dynamic Text Display, coded in python.
The problem:
When I start game engine (press 'p' at keyboard) in the score layer alone, I got this visualization:

But, oddly, when I'm executing the two layers together, I got this visualization:

Instead of show the zeros, show @s!
As a score, it works correctly.
But, instead of show any number, show always @s. Score working:

What is going on?

Sharing the code could help us figure out. also maybe a .blend file.

The dynamic text was programmed like this tutorial: https://www.youtube.com/watch?v=GKO4jfAHtjk (too much lines to share here). This is an plan, with an image uv .tga associated (arial font, in case), and works with a sensor, a logic controller and a property actuator. The actuator assign the property value. The value comes from a python code, a module associated with controller.

In the material settings, when game engine is active have you turned on the text option in the game settings? look about 3 mins into the video.

Yes, I've made every step.


text:
"find missing files" doesnt find the audio strip
I did an edit in the VSE and then moved the source files (MOV videos) in another directory.
So i launched a "find missing files" to recover the files. Everything goes well, for the video part of the strips, instead the audio part of the videos becomes transparent and no audio is loaded or played.
I would like the audio part to be recovered as well...
Shouldnt the audio strips get extracted again from the same MOV files they took it originally from?
Is there something i'm missing?

Maybe you can use some python scripting to update the paths to your audio files dependant on their corresponding video files. And you might file this as a Bug Report?

guess i'll have a second look at it..;)


text:
What does Light Portal mean?
I've heard a lot about this 'cool' feature in the next release and I wonder what it is. Any infos?

Light Portals are objects that help Cycles render interior scenes  (incomming light) more efficiently.

recommended: http://blender.stackexchange.com/a/33154/3710

Light portals are a method of reducing noise, which, as you already noted, is new in 2.75.
Light portals help to remove noise by guiding rays from the environment through the openings where a portal is positioned. Because of the fact that they are designed for openings, they are most useful for architectural scenes.
It acts a bit like setting a light or HDR set to multiple importance.
Sampling is also slower when using portals, but usually the reduced noise more than makes up for the time lost while sampling.
To add a light portal, add an area lamp, and position it in the center of an opening. Make sure that it is facing inside. Then, using the lamp settings, change the dimensions of the lamp to fit the opening, and check the portal checkbox

Here are two comparisons from the docs:

It is a plane that defines where the most of environment light will come into the scene, so the renderer can sample light more efficiently.
Usually speeds up indoor rendering. The sample takes longer time but the noise will clear out after fewer samples.
Multiple light portals can be used, but it's only good to place them on the main light sources - like windows (or a TV if it's the main source of light in a night scene).

Light portals aren't for all light, but instead, only for environment light.

(Light) Portal is a setting for Area Lamps that helps sample enviroment light more efficiently in Cycles. It's useful for interiors where enviroment light is coming through a window or door. You can get a clean image with less samples, although each sample takes a little more to render.
The end result is a small to mid speed increase, it depends on your scene.
In my experience they also seem to change the lighting subtly, giving it more of a "direction".

all_licenses: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How to animate text being revealed on the screen

An animation of an object appears under something small or invisible to camera

I don't quite under stand what you are asking, nor what your description is pointing at. Could you please be a little more specific with your question.

From my experience text objects do not work very well with booleans (due to some letters in some fonts being non-manifold).
This is a method that can be adapted to work on anything:

You need to create a gradient mask for your material that will "stay static" despite the object movement (you do that by using object mapping and adding/subtracting the object's position from it):

link to full image
Great thing about a mask is that it can be faded on the interface.
The Add node is just driven by the text position.x.
The mask is used to mix Transparent and any other shader.
If you need to place such Text somewhere you need to parent it to something first and move it through parent.

This is the result:

And the blend file:

Looking great, though I wonder how to make an animation that simulates a keyboard typing.

@Gonzou You just need to move the text by increments, that's all, it's not very clear from the question what the intention is..

Would be non-trivial to define the increments for non-mono-spaced fonts.

@ajwood yep, very true. That would be a job for another addon or better for the one that exists but improved. It would have to measure the width and spacing of characters and offset the position of text accordingly.

There is a typing text addon here: https://github.com/meta-androcto/blenderpython/blob/master/scripts/addons_extern/animate_text.py
I haven't used it in a long time, but it still works in 2.75. The addon claims it is under the tool shelf in the 3D view, but the settings are actually under the text properties. Activate the addon and the new settings will appear at or near the bottom of the text properties.
I made a video describing basic usage. There's more, but I don't know the addon very well. I don't know how to embed on SE, so I guess a link will suffice.
https://www.youtube.com/watch?v=JrbIHxhNzrY


text:
How to use Mask to hide a specific object?
In this scene, I want the blue disk to be invisible to the camera, hide the part of text that disk covers while keeping the plane all visible.

Also see: http://blender.stackexchange.com/questions/32032/mask-out-certain-objects and http://blender.stackexchange.com/questions/24169/using-an-object-as-a-clipping-mask-for-another-object?lq=1


text:
How to link animation of object A to object B while keeping A's original location?
When I link animation data of a cube to a sphere and animate, cube snaps to the sphere's location and take the same path while moving! How to link while keeping cube's original location?

One way to recycle motion without having the objects overlap is to use NLAs.  This is not exactly trivial.  You have to

place the action inside an action strip
put a location keyframe on the second object
change the action strip blending mode from Replace to Add

Another strategy would be to make the second object a child of an Empty or other object.  You can adjust the location of the parent to set the origin of the modified coordinate system.
In the following screenshot you can see the lower left window is the NLA editor illustrating that Cube.001 has one NlaTrack with the shared action, and its primary action is the offset keyframe.  The action strip has its Blending set to Add.
In the upper right outliner window you can see Cube.002 is parented to an Empty.

Once you link the two objects, click on the cube and move to where you want or its original location. Then use the sphere to control both of their locations together.
hope this was helpful!
-Noah


text:
How to do a bezier interpolation mode animation along a path?
When I parent an object to follow a path and animate it, I only get a linear mode animation and changing that in Grapth Editor to bezier doesn't work! How to do that?

Related - https://blender.stackexchange.com/questions/31578/how-to-change-camera-movement-speed-on-path-during-animation. There actually is another way with adding several Envelope F-Modifiers in the N panel of Graph Editor. But it's very hard to setup, especially when there're a lot of points


text:
Can you change the font in the Sequencer new Text Effect?
I find the default boring and wonder how to change it.

related: http://blender.stackexchange.com/questions/32585/scrolling-credits

No, it's not possible to change the font on the Text effect as of 2.76. Here's a workaround

Just had a spelunk into the source and found that the code for generating the VSE Text effect and the Stamp are the same and all the references to the font are hard coded. The developer even marked the lines with // XXX which appears to be a flag for janky code. Look for "do_text_effect" in "source/blender/blenkernel/intern/seqeffects.c" Maybe it will be fixed in 2.8

Yes, in the new 2.8 beta now you can. There now is a font selection box in the Text Effect Strip properties panel.

can you point me to a tutorial that explains how to do this? I don't see anything about adjusting the font in the VSE...is there an Add-On I'm missing? I searched the Blender Manual and I Googled it and I even searched for add-ons but I'm not seeing anything. Any assistance would be helpful. Thanks!

It was explained in Blender Today.


text:
How to make the sun lamp not the HDR cast shadow in Cycles?
I have an object that's lit by an HDR and a sun lamp. I want that object to cast shadow by the light coming from sun lamp only. How to do that?

I think that if you are using an image to lighten the object, necessarily you'll get shadows too. You can dampen their strenght, soften the contrast between light and dark areas, make the shadows border smoother, but not avoid them completetly. What would the scene look like without the sun lamp in your opinion? Could you specify a little bit your question?


text:
Video Quality Loss after Rendering in VSE
I rendered an animation in a 720p-png format and the images looked HQ. After re-rendering them into video in VSE the video lost its quality and looked blurred. (I tried higher bitrates and different formats but nothing worked). How to keep my video quality as good as images?

Have you tried using H.264 and the H.264 preset? I had similar issues and this worked just fine.

Rendering with the file format AVI Raw should help you retain your Quality ;-)
But if you don't want to have your file sizes explode try H.264 instead.

You can reduce your Bitrate to 5000 for your 720p video. Change your GOP Size to half your Frame Rate.


text:
Blue line in the Image Strip not showing

When I click and drag the little arrow; the blue line showing the real lenght of frames dones't appear. It does with all tutos I watched but with me! Why?

In the Video Sequence Editor:
View > Show offsets


text:
Unlink image from the Image Editor using Python
I basically want to press this X button using python,
or possible just switch to another image.

The reason why I want to do this is because I'm using the image editor to move and scale the UV vertices of an object, and it doesn't work if the "Rendered Result" image is selected in the image editor, any other image can be selected, just not this one.
bpy.context.area.type = 'IMAGE_EDITOR'
bpy.ops.uv.select_all(action='TOGGLE')
bpy.ops.transform.resize(value=(0,0,0))
bpy.ops.transform.translate(value=(-tx,-ty,0))

Check if it is a render image then switch to another one (in here no image is chosen )
for area in bpy.context.screen.areas :
    if area.type == 'IMAGE_EDITOR' :
        if area.spaces.active.image.type == 'RENDER_RESULT' :
            area.spaces.active.image = None

@rymdnisse you are welcome


text:
Chose file format when taking a screenshot with python
I'm trying to take a screenshot with Python using
bpy.ops.screen.screenshot()
However I can't figure out how to chose what file format to save the image as. It will by default be saved as a PNG (see screenshot below). Does anyone know if there would be a way to chose another file format (such as jpeg, bmp etc.) when saving a screenshot through python?
Thanks in advance! :)

Currently there is no way, you can only save directly to a PNG.
This is caused by the way the operator works, where the options to choose the image format are only initialized when the file-selector is used.

Ah, alright :/ Well, thanks for your answer!


text:
How to stop blender game engine using Python upon reaching a condition in the script?
I have the following script(pistonMover.py) which runs in the Blender "game engine" mode and I want to stop the game engine when posdiff is less than 0.0001.
import bge
import COM
import time as t

def calc_com():
    obj_list_real = []
    for item in bge.logic.getCurrentScene().objects:
        try:
            if item.name.startswith('Cube') and item.name != 'Cube.004':
                temp_dict = {}
                temp_dict['x'] = item.worldPosition.x
                temp_dict['y'] = item.worldPosition.y
                temp_dict['z'] = item.worldPosition.z
                temp_dict['mass'] = item.mass
                #temp_dict['name'] = item.name
                obj_list_real.append(temp_dict)
            if item.name.startswith('obj_'):
                temp_dict = {}
                temp_dict['x'] = item.worldPosition.x
                temp_dict['y'] = item.worldPosition.y
                temp_dict['z'] = item.worldPosition.z
                temp_dict['mass'] = item.mass
                obj_list_real.append(temp_dict)
        except AttributeError:
            pass
    com = COM.COM(obj_list_real)
    return com

def getPistonpos():
    pistonpos = 0
    for item in bge.logic.getCurrentScene().objects:
        if item.name == "Cylinder":
            pistonpos = item.worldPosition.y
            break
    return pistonpos

def main():
    cont = bge.logic.getCurrentController()
    player = cont.owner
    scene = bge.logic.getCurrentScene()
    keyboard = bge.logic.keyboard
    player.localPosition.y -=0.1
    pistonpos = 0
    flag = False
    try:
        pistonpos = bge.logic.globalDict['pistonpos']
        flag = True
    except KeyError:
        bge.logic.globalDict['pistonpos'] = getPistonpos()
    posdiff = abs(getPistonpos() - pistonpos)
    if posdiff < 0.0001 and flag:
        print(posdiff)
    bge.logic.globalDict['pistonpos'] = getPistonpos()
    if bge.logic.KX_INPUT_ACTIVE == keyboard.events[bge.events.DOWNARROWKEY]:
        calc_com()

main()

I have tested this script and works perfectly but, I was unable to find a way to stop game engine anywhere. Also, I invoke this script using bpy.ops.wm.blenderplayer_start() from Blender in "render mode" using another script called "renderer.py". I want to do this since I want to run this simulation for 100 times and as I said, I want to stop it upon reaching a condition in every simulation.
Here's how my game logic looks like.

Thanks in advance!

It's very simple, you just have to connect a Game Actuator to your script Controller and set it to "Quit Game".
Add this actuator to your script by doing this:
gameactu = cont.actuators['Game']

if posdiff < 0.0001: # You can also try 0.0002
    cont.activate(gameactu) # I just try it works.

Here a picture:

You can do this without the Actuator, see the manual.

... Or just call bge.logic.endGame() ...
Be mindful that the game will take a few secs to close, so unless you do something like:
d = GameLogic.globalDict
if 'shutdown' in d:
    print('Shutting down...')
    bge.logic.endGame()
else:
    *Your code here*
    if <its time to quit>:
        d['shutdown']=True

your code might run again.

thanks, this very simple but elegant answer has really gotten buried.


text:
Script access to tangent and bitangent, per face: how?
Suppose you have a mesh; you go into Edit mode,
set Transform Orientation to Normal,
show 3D manipulator widget,
Pivot Point = Active Element,
face select mode, and then you select any one face:
immediately you will see a blue arrow representing the face normal,
and also a red and a green arrow representing the face's tangent and bitangent.
What is the most straightforward way to refer
to said tangent and bitangent vectors from a Python script?
The API documentation confuses me with loops and uv's, yet, clearly,
Blender assigns a tangent and bitangent to each face without hesitation!

I believe what you are looking for is 'calc_tangents'. http://elysiun.com/forum/showthread.php?338922-How-do-I-create-and-view-the-tangents-bitangents-for-a-mesh

Thank you, gentlemen!
To me, each face has a single loop that defines the perimeter, hence defines the face itself. But the API speaks of multiple loops, each with a single vertex??
Average, fine; thank you.
But Blender surely has a tangent and bitangent
already stored and associated with each face,
as evidenced by the instantaneous appearance of those little XYZ arrows when Transform Orientation = Normal.
Isn't that so?

You access tangents and bitangents from MeshLoops:
import bpy
me = bpy.context.active_object.data

# tangents have to be pre-calculated
# this will also calculate loop normal
me.calc_tangents()

# loop faces
for face in me.polygons:
    # loop over face loop
    for vert in [me.loops[i] for i in face.loop_indices]:
        tangent = vert.tangent
        normal = vert.normal
        bitangent = vert.bitangent_sign * normal.cross(tangent)

To get tangent and bitangent of some face you need to average tangents and bitangents of every vertex in that face loop.

There is a convenience attribute on polygons you can use to loop over face loops: face.loop_indices. It's already a range object. for vert in [me.loops[i] for i in face.loop_indices]: should suffice.

Jerryno; CoDEmanX: face.loop_indices
Duly noted: thank you!

I made this test comparing normals coming from the loops and the ones that are stored in me.vertices[x].normal, and they are different. Shouldn't those be exactly the same? I've made a separate question here http://blender.stackexchange.com/questions/71356/vertex-normals-different-from-loop-normals


text:
How do I pack textures for sending off to a render farm
Whenever i try to send a project off to a render farm such as sheepit, it says it needs the textures packing with the file in order to render correctly.
How would I do this?


text:
How do I export an outline of my UV map so that I can paint a texture in an external editor?
I'd like to edit a JPG texture in an external image editor. To do this accurately, I'd like to export an image showing the outline of my UV map, that I can trace over in the external editor. I'm using Blender 2.73, the mesh is unwrapped, I'm looking at it in the UV editor.


text:
Materials show up in solid view, but just appear black in material view
I'm trying to apply some simple materials to different parts of a mesh. They don't have textures, just diffuse colour at present. In object mode, they show up in "solid" view, but in "material" view, they just show as solid black (in texture view, the mesh displays as white but shaded). How can I get the materials to show in "material" view?
Thanks.
Solid view, materials are visible:

Material view, everything is black (bottom half of material panel is visible):

Also, as a related point, when I tab into edit mode, I can only see the bone weights when in "solid" mode (and again, solid black in object mode), so I have no way of viewing the materials at all.
I have a light source, scale isn't negative, I'm not in local view, what have I messed up?

if that doesn't work, go to each object enter edit, go to the materials tab and check shadeless.

Make sure your light source diffuse and specular check box options are checked.  Later you can adjust more artistically.

If needed.  Delete all lights and materials and add new ones with no modifications except color.  Sometimes through experimenting we click many settings and do not know the click history.  Deleting and adding again may restore defaults.

Thank you, you got me playing around with the lights. Specular and diffuse were checked, so that wasn't it. But what has solved the problem is changing the lamp type. It was an Area lamp. Changing it to any other type, and the material becomes visible; switch it to Area and the model goes solid black. Why would that be though?

Area lamps are about simulating a soft lightsource by using a large grid of point lights or so. Realtime renderers are usually limited to single or low double digit light sources and work with lighting systems designed for point/spot/sun lamps that have a single origin point. My bestguess anyway.

Thanks both of you for your answers. I'd upvote them both but my reputation is too low :-(

That arrow is just way too fancy.

My solution to this problem in Blender 2.79, which interestingly doesn't occur in Blender 2.80, was to turn on Environment Lighting (in World), as pictured.

Notably, I could also solve this problem by using any light source other than a Sun. I opted for a Hemi light source, and for some reason that escapes me, a Sun light source produced only a solid black object in Material mode or Render mode.
Environment Lighting option was by far the most convenient solution, but I've noted two solutions which worked for me.


text:
Concatenate movie clips with differing fps?
Suppose you have two .mp4 movie clips, with well-synched audio,
that you can view and listen to in any Web browser, in succession, even though their frame rate is different.Question:   What is the simplest way to concatenate those two into a single file?It seems that this should be such a frequent and desirable taskfor anyone going from 3D modeling, to rendering, to animation, no?E.g. suppose you are working on a scene intended for a brief animation,where motion is slow enough in the first ten secondsthat you are satisfied with half of the basic 24 fps, but then comes four seconds of motion so fast and sweeping that you want twice that basic rate.Suppose the rendering of each frame takes about a minute:that means that the first ten seconds would take about two hoursfrom scene to image sequence, but the next four seconds would take over three hours.After a lot of to and fro between modeling and rendering, you decide you want to show this to your peers:you then make two movie clips (with 12 and 48 fps respectively),add a sound track to each, and presto!All that’s missing now, is to concatenate those two into a single file. How?Note that we’re talking same dimensions, same codec!

You have to choose the side effect that you prefer. If the frame rates differ then there will be either duplication of frames to stretch the lower frame rate to the higher rate OR you will drop frames to get the high down to the low. Use the VSE speed effect strip to stretch one to the other.

Thank you!
But there really should be no side effect, since we don’t want to alter the movie clips in any way
except to have them play in immediate succession, that’s all.
My suspicion is that that needs to be achieved either with some clever Python code
for Blender, or, with an external app like, ffmpeg ?

In fact, I just saw that ffmpeg (which is what Blender uses, internally)
has a concat command: https://ffmpeg.org/ffmpeg-all.html#toc-concat-3
which accepts different frame rates!
(Of course, audio and video should be well synched in each file.)

Hmm, well let me know how differing playback rates with in one file goes. I know that screen captures can have variable frame rates but they typically require special codecs.


text:
Cycles: access actual length of hair strand?
For materials pertaining to hair strands, Cycles gives us a Hair Info node with a scalar output called Intercept,
whose value will be 0 at the root and 1 at the tip, irrespective of how long the hair strand actually is (in Blender units, e.g. meters).
Knowing where we are along a hair strand, we can achieve visual effects such as banding along each hair.
But (by the use of vertex groups for density, kink, and length) I also wish to bring about
a smooth transition from hairless to full-crop —e.g. along the nape of a character’s neck—
and this will result in a range of hair lengths that can span an order of magnitude.
If we lack information on the actual length of a hair strand, any banding algorithm
that relies on Intercept and works well for full-length strands
will necessarily give a compressed and visually dissatisfying result on the shortest hairs:

To compensate, algorithmically, we need the ability
to read the actual length of the strand being rendered. Actual length information is, of course, available somewhere inside Blender
before the Cycles rendering is invoked.
Is there any way for a materials developer to read that information, in Blender 2.79 or 2.80?
Or, at the very least, is there a way to read the vertex weight of a vertex group
(such as: the one that is modifying hair length)?

Alright, here is a provisional solution, as evidenced by this image:

(compare with my original, above).
A satisfactory solution would make use of each hair strand’s actual length at render time.
This length depends on many factors, including:

The hair particle’s initial velocity (normal and tangent).
The influence of gravity, if any.
Serious kink, notably Spiral.
Added randomness.
Surprisingly, the damping factor.
The vertex group for length control, if any.

So, the product of intercept times length control is proportional,
only approximately, to the hair strand’s actual length,
but this is what I use for the image above, and it is the reason why I call this a provisional solution.
Unfortunately, vertex weights are not yet (September 2018) available to the Cycles material developer;
not through the Attribute node, not through OSL, and not even through some clever driver expression:
so says Grand Guru Brecht Van Lommel, here.
Thus, my provisional —and clumsy— solution, suggested by Brecht himself,
is to copy the length control information over to a Vertex Color layer, which is,
oddly enough, accessible via the Cycles Attribute node.
Here is a quick Python hack to achieve said copy:
#Given: active object with active vertex group and active vertex color layer
#
#Does: Copies vertex weights into red channel of vertex color layer, leaves rest untouched.
#
#© Tom Telos 2018, submitted freely to interested users, for experimental purposes only.
#
import bpy

bpy.ops.object.mode_set(mode = 'OBJECT')
ObA = bpy.context.active_object
if ObA == None : raise RuntimeError("No active object")
else : print( "Active object" , ObA.name , "found." )

VgA = ObA.vertex_groups.active
if VgA == None : raise RuntimeError("No active vertex group")
else : print( ObA.name , "act vx gp " , VgA.name , " found." )

VcA = ObA.data.vertex_colors.active
if VcA == None : raise RuntimeError("No active vertex color layer")
else : print( ObA.name , "act vx colors " , VcA.name , " found." )

for loop in ObA.data.loops : #Crazy, but this works.
    iV = loop.vertex_index
    iL = loop.index
    try :  #fails if vertex not in vg
        VcA.data[iL].color[0] = VgA.weight(iV) #weight() not [] !
    except: continue

It is in lieu of Varkenvarken’s much more sophisticated addon
which, unfortunately, does not work for me with recent builds of Blender 2.79,
ostensibly because of a Python version mismatch, but, more likely because,
in recent Blender 2.79 builds, the number of vertex color “channels”
has been increased from 3 to 4.
My hack is simply paste-and-run,
and assumes that there is an active object with an active vertex group and an active vertex color layer.
For each vertex in the active vertex group, it copies its weight to the red channel of the color layer.
That’s all. It does not modify the vertex color of any vertex not present in the vertex group.
P.S. Brecht Van Lommel, here, confirms that, as of September 2018, there is no user-level access to actual hair length.

You can find the vertex weight in the "N" properties panel when - in edit mode -  you select a vertex that has at least some weight relative to a vertex group.

Thank you. Yes. But, how do I refer to the weight,
in a particular vertex group, of the vertex closest to
the root of the hair strand being rendered?
How can we refer to that, in a Cycles nodes diagram,
or in an OSL script, or, possibly, in a driver?

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/


text:
How do I resize an armature without ruining its poses?
I have an armature that I need to resize. When I scale it and apply the scale changes, all of the armature's associated poses/animations are ruined, because the position data for bones in the poses wasn't scaled with it. The way I understand it, poses work by storing data about a bone relative to the "rest pose" position of the bone's parent. It's this position data that doesn't change when the armature's size is changed, resulting in the pose being rendered unusable. If I scale the armature and don't apply the scale changes, everything works correctly; the armature is uniformly resized and all the poses/animations are preserved. But as soon as I control + a and apply the new scale, I end up with a crushed mess.
The armature, posed:

The armature, after having been scaled, but without the scale applied:

After applying the scale:

Is there some way to make the pose data scale along with the armature (so that when a size change would be applied nothing would appear to change)? It seems like a very important thing, and that there should be some sort of "scale poses with armatures" option.
TL;DR: How do you scale an armature along with its associated poses/animations?

Parent everything to an empty. Scale the empty.

You will have to scale the pose data's F-curves (you don't need to scale the armature and apply the scale then..):

You need to have keys for scale and location for every bone
Hide rotation f-curves for every bone (don't want to alter rotations)
Set pivot to 2D Cursor and position the cursor so the Y is 0 and X is any frame:

Select all visible (A). S+Y to scale animations/poses in pose space. Tadaa!

What if you have various animation?

@DouglasRosa Then you do this for all animations F-curves or you write a script that does it for all if there are too many. A hint how to do it is here: http://blender.stackexchange.com/questions/65020/modifying-fcurve-values-on-armature-bones-via-python

It works for the simple cube but I found out how to do it to the armature with mesh connected, because sometimes stuff like this simply happens.

When you just scale it and then press Ctrl + A.
I accidentally found that if you scale it and instead of Ctrl + A use Scale to Deltas it works just fine.

My goal was to change dimensions from Z=3.45 to Z=2.00 without changing 111 scale proportion. And it works just fine.
My blender version is 4.01.


text:
How to Make a Rotation on Two Different Axes?
How to achieve a rotation animation like this (GIF below)?
Where the text rotates on both orange point and its origin point axes, so it stays horizontal along its rotation.
Thanks!

Copy location constraint
The easiest way to keep the text horizontal is to not rotate it at all. Let's see the movement from another perspective: it's a text, that doesn't rotate, but it's origin is moving on a circular rail.
Use an empty to build a pivot in the center and another to set the position of the object's origin. Parent the last empty to the first one and animate the pivot to build a moving point.
Now add a constraint to the text object's location targeting the moving empty. The text will not rotate (why whould it?), but it's following the movement, achieving the desired effect.

HOW DO YOU DO THAT?! all i can do i just add bones and make eyes (with bones) and model!


text:
FBX Animation Export Problem
I have a problem when exporting animation in FBX to other softwares. Even if I import the FBX file back to Blender the animation goes wrong.
(I baked all actions by the way). File is below:
http://pasteall.org/blend/index.php?id=49510


text:
Materials tab missing

I am working on blender using a friend's computer, and I cannot find the materials tab. I circled the red area where it is usually located for me.

It's there, but it's hidden because the properties editor is not wide enough.
You need to either

Scroll the header over a bit by clicking and dragging on the tabs with  MMB.

or

Expand the Properties editor by clicking and dragging on the boundary between the properties editor and the 3D view.

Example:


text:
How do I export as an FBX with colors?
Disclaimer:  I am not an artist.
I created a model in blender.  I switched my mode to "Texture Paint".  I painted the model.  When I export as an FBX or switch back to "Object Mode", my paint goes away.  I am opening my FBX View 3D, a native Windows 3D model viewer.
Why does this happen, and how can I prevent it from happening?

Related - https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures. As long as you saved the texture you painted on it will be accessible for setting up material, either in Blender (if for rendering) or in 3-d party application. If the latter then not much you can do in Blender except for exporting fbx and recreating material which will be using that saved texture in the 3-d party application / render engine.

Please take a look of the following image:

Please Save as image (so your edit become an external file on your drive as image) and  than add the Fake user by clicking the F button as high lighted.
I hope it will help :) good luck!

Or may be use a "Pack as PNG" option


text:
how to order the objects in the dope sheet
Is there a way to order the objects in the dope sheet. I know you can move the channels up with the page up button and down with page down button. But this doesn't work with the objects, is there a way to do this?

This question really need to be revived. Someone put a bounty?

You double click the object name on the left and by changing it's name you can order it alphabetically and numerically. Cube.001 is above Cube.002.
It takes some time but there really is no other convenient way and this actually helps organize your scene! :)

As a workaround for more oversight, you could click the little arrow in the dopesheet footer (little arrow | ghost | rescue ring), to only display the currently selected objects. select different objects in the viewport or the outliner.

Yes I know that function, but i want to see all the objects in a specific order so i can easily offset keyframes.

ah i dont know then :(.

In the Dope Sheet Editor Type. There is a option called Move, under Channel. You can move the Dope Sheet channels by either accessing that selection. Or through the shortcut Page Up or page down to move it in it's respective description when selecting the specific channel.


text:
Annotation in the VSE
How does the annotation work in the VSE, in blender 2.8 beta? If I check the box annotation in the VSE and add a layer nothing happens. What am I missing?

After adding a layer. Hold D to draw on VSE preview window.
Holding D and drawing with right click will bring up the eraser.You can turn on Onion Skinning in the options panel as well.

Does it only work in the preview window, and not in the sequencer?

If you mean the window with the actual video strips.. Then no. You can only draw in the preview window or in the 3d viewport as far as i know.

Get 2.83 and there will be a toolbar with an annotation tool in the preview.


text:
FBX Importer AssertionError (unknown location -1) when importing .fbx from wow model viewer
Using version 2.75 I am unable to import .fbx files from WoW model viewer into blender.
Attempting to do so throws an AssertionError.
Assertion Error

location: <unknown location>:-1

Does anyone know what is going on here and what I can do to fix it?

That kind of issue must be reported to our tracker, with an .fbx example file to reproduce it…

Workaround:
I had a similar problem but I could not find a solution. It turned out that Visual Studio 2013 (Professional; I don't know whether the Express version is enough) and Unity (a gaming engine; in case you didn't know) were both able to import the file correctly.
Finally, I imported the file into Visual Studio 2013 and saved it as a .obj file which could then be imported correctly into blender.
EDIT
However, it worked correctly using the Blender 2.72b version.


text:
Get strength, velocity, direction of force field at specific position
is it possible to get parameters like strength and direaction of a forcefield at a specific position with Python?
For example I would like to know how strong a turbulence field is and in which direction it goes at position 1.0/1.0/1.0.


text:
Trying to make a spine-like structure in blender
So, I have the structure of a single vertebra (roughly) and an armature bone to dictate it's motion. What I want to know is, is there any way to generate a series of vertebrae, one on top of the other, with their armature bones already linked together? I REALLY don't want to place and link every single bone together, when there might be more than 50 of them. Also, I'd like the general scaling of each vertebra to be decreasing as each structure is generated. I know the array modifier can do the first part of that, but it doesn't copy the bones, and I don't know how to add scaling to it.

I would do it like this:
- Create the first vertebra
- Shift D Z to duplicate and move upward
- Shift R to repeat the last operation
- S for scaling the needed
- at the end select all the vertebrae and ctrl J Join them
- add a curve modifier to adjust the shape of the whole object

Then create a single bone
in edit mode extrude the bone moving the tip toward the top of the next vertebra
extrude again ...
at the end parent the object to the armature using automatic wheight

I think it can take half an hour for 50-60 pieces
Maybe for 5000 you would need an automated way
Remember also that a long bone can be subdivided n times,  with the W key menu.

Better to use python for highly repetitive tasks like this. Here's a python script automate the generation of the bone and vertebrae pairs:
#Script assumes existence of "VertBone1" armature and "Vertebrae1" object with the "Vertebrae1" object parented to the "VertBone1" armature

import bpy

gapAmt = 0.1
scaleAmt = 0.9
numVertebraes = 6

#deselect all objects
bpy.ops.object.select_all(action='TOGGLE')
bpy.ops.object.select_all(action='DESELECT')

for i in range(1, numVertebraes):

    #set our target object names
    boneName = str("VertBone"+str(i))
    vertebraeName = str("Vertebrae"+str(i))

    #iterate over all objects and select our target objects
    for o in bpy.data.objects:
        o.select = False
        if o.name == boneName or o.name == vertebraeName:
            o.select = True
            if o.name == vertebraeName:
                #get the height of the current vertebrae
                curVT = o.dimensions.z

    #duplicate both objects
    bpy.ops.object.duplicate(linked=False)

    newVert = bpy.data.objects[vertebraeName +".001"]
    newBone = bpy.data.objects[boneName +".001"]

    newVert.select = True
    newVert.name = "Vertebrae" + str(i+1)
    newBone.select = False

    #scale vertebrae object
    bpy.ops.transform.resize(value=(scaleAmt,scaleAmt,scaleAmt))
    bpy.ops.object.transform_apply(location=False, rotation=False, scale=True)
    newVert.select = False

    newBone.select = True
    newBone.name = "VertBone" + str(i+1)

    #set translation amount to equal height of current vertebrae plus gap amount
    moveAmt = curVT+gapAmt
    bpy.ops.transform.translate(value=(0, 0, moveAmt))

Note: each bone will be a separate armature. You may have to join them if you only want one armature.


text:
How to make slow motion for Particles hair?
I want to make quick turn of character's head with slow motion. I'm making animation at 24 fps & I don't want to remake it at 60 fps. Is there any way to do slow motion for Particles hair while animating?

There are two options:
Option # 1
You can bake your hair particles system, go to the timeline, and stretch/extend the keyframes to make them slow motion. This basically can be done if you first animate your monkey rotation fast (make the keyframes closer together) and then after baking your hair particles system animation, extend/stretch the keyframes in the timeline to fit your ideal slow-mo length (on both the monkey rotation and hair keyframes).
Option # 2
You can play with these settings in the hair dynamics, such as the stiffness, weight, and damping.
Option # 3 (The Best)
Enable the Advanced checkbox in the hair particles. Now if you scroll down and go to Physics you can decrease or increase the Timesteps value to control the speed of your animation.
How to Keyframe these values:
Hover over the values and press I or click the dot icon in front of them:

The second option, unfortunately, is only suitable if all movement is in slow motion, and not partially, since keyframes can't be set on these values.
As for the first option... where are keyframes for baked particles? I baked hair in fast motion, but in timeline there is only red stripe at bottom, but there are no keyframes for particles themselves. There's keyframes only for monkey.

@Juliya Should be visible if you check some options, but leave method 1 and 2, check method 3

@Juliya Keyframes Can be set on these values. Just press I while hovering over the value box, or just press the dot icon in front of the values to keyframe.

Change values on Timestep can only if hair hasn't been changed in any way in Particle edit. If some hairstyle is done, then Timestep becomes inactive unfortunately.

@Juliya Then just use Method 1 and search up some tutorials on youtube on how to view your baked keyframes of hair particles.

Unfortunately I couldn't find how to bake hair particles to keyframes. I also tried to convert hair to mesh, but instead of animation, I got static object. And I tried to slow down animation through NLA but that doesn't affect on hair either, only on monkey.

@Juliya then animate the keyframes on the values of method 2?  Other than that I would say, you will have to render at 60 fps to get a smooth slow-mo animation, sometimes the hard way is the only way... Maybe the hair bake could be visible in the graph editor? Or maybe there's an option to apply the bake?

In Graph editor also doesn't show baked hair keyframes.
And how apply baking? I know that can only be applied in one single pose, not in animation.


text:
How to make effect of burning objects from Particles?
How to make so that Boolean affect on color & shape of particles?
Here's example, I need to create effect so that grass from Particles burns. But grass doesn't change color & shape from Boolean & Dynamic paint like ground does. Particles just disappear when circle narrows.
I guess that for particles need to use not Dynamic paint, but something else. The only thing that comes to my mind is converting particles to mesh, but this is inconvenient variant, especially when particles are animated.
How to make so that Boolean affect on color & shape of particles? Or maybe not Boolean, but something else. In general, how to make effect of burning particles (on the example of burning grass or something similar)?

I dont think there is an easy solution in the direction your heading.
And probaply no easy solutions exists.
But know that Blender understands Python, and with that it should be possible.
If you know the locations of the object replace them, or better use shape keys on them to shrink them. Then be able to move a texture over the object so it turns black from top to bottom. Doing this with python might not be easy, though all actions you do are logged inside
Maybe animation nodes could allow something like this (but i'm not sure).
Generating trees with leaves is one of the goals though.

Oh no, I don't know how to use Python & Animation nodes. OK, thanks for answer, I'll try to find some alternative.


text:
Sharp edges & white dots when using Depth in Compositing
When I try to make fog with Depth in Cycles, noise appears on objects with transparent material & sharp edges are formed on the edges of objects even without Transparent. Every time I try to do aerial perspective, nothing coming out. Or I have to use Volumetric light, which takes too long rendering & needs a lot of samples to get rid of the fireflies. Either I'm trying to make fog in Photoshop. And for animations, these methods are generally not suitable. Fog adjusted with Depth looks very good, but the resulting artifacts spoil the whole picture. I tried to find the answer in internet, but all methods that were indicated there didn't work. Help me please please please, how to make fog correctly so that there are no sharp edges at the edges & white dots on Transparent?


text:
Blender 2.8 Undo like in 2.79
How to undo last actions in Blender 2.8 / 2.9 without undoing actions in Edit mode, Sculpt mode & Particle edit? I.e. how to make Undo work the same way as in Blender 2.79? It often happens that need to edit something in Edit mode, Sculpt mode or Particle edit & if I don't like the result, then in 2.79 I can easily undo large number of actions at once. In 2.8, undoing absolutely every action is completely inconvenient. Maybe there is some hotkey or setting to undo like in 2.7?


text:
Sweat on body in Cycles
I'm trying to make sweat with particles, but Glass material creates very large shadow on skin & it produces black drops. I tried different settings, but either black drops, or reflections disappear, or no drops are visible. Please, can you tell me which nodes should be for realistic drops on body?

maybe try with a map? see the answer here: https://blenderartists.org/t/how-do-i-to-get-wet-skin-and-lips/1262283/2

Yes, I saw this tutorial, but I need drops.


text:
How to split areas of one material for ID mask in Compositing in Cycles?
How in Compositing to select only area for ID mask, which is created in material using mask (Fac)? In the example in this picture, there is one material & with help of mask, areas with Emission are added there. For example, I want to make glow for Emission areas in Compositing, but it's added to the entire material, and not just to single element, and therefore the whole object is glow, not concretely areas with Emission.


text:
Layers tab not showing

Usually my layers tab appears in the area of the red circle, but I did something that changed it. I would like to know how to get it back. Thanks!

You're in local view press Numpad '/'

You pressed the Numpad / key switching you into Local View. Scene layers and lock buttons do not show there. Press  Numpad / again to go back into Global view

some of us use tenkeyless >:(

For those of us who use a laptop without a Numpad: Object Mode, View, View Global/Local

thanks, it worked. I got so stressed when all my models just disappered and i didn't even remembered what i pressed.

Its the : key on a german keyboard


text:
Can you use a face to slice other faces?
I am pretty new to Blender (currently working on my 3rd model). I need to tidy up the in/underside of the model to help reduce the impact on performance in the game it will be going into.

Is there a way I can use the flat face to slice the crystalline structures to make new edges so I can delete the unwanted sections?

Try the Boolean modifier. I'm not sure, but it might require volumes, not faces, so just extrude them (press E).

There are two methods that are standing out to me.
One is the boolean modifier. For this, you need to make the crystalline structures a separate object. Than add a boolean modifier to one of the objects and use the union type. This will actually join the objects, the downsides are that it can create sloppy topology so it really depends on how willing you are to have n-gons and triangles in your mesh.
The other one is the intersect tool which is new with 2.72. For this you need to be in edit mode and have everything selected. The easiest way to find it is to use the spacebar search menu. Just search "intersect".
Here's a demo on the intersect tool:
link
This won't join the two meshes like the boolean modifier, but instead it puts the verts where they need to be and leaves the user up to deciding what to do with the mesh.
I hope this helps.

Just use the booolean, its easier.

I'm not so sure, I'm personally thinking that I would try the intersect tool. I find that the boolean modifier is a bit too buggy so I avoid it in most cases unless I really don't care about topology.

I don't really care about topology :) But you're right.


text:
Is there a way to deinterlace footage using Blender?
I have a camera that has always seemed to give me bad video because of interlacing, and until I watched this video, I always thought that it was just a limitation of the camera.
From that video, I learned that video can be deinterlaced, is it possible to this using Blender?

in the video sequence editor you have an option in the properties panel --> filter tab you can check de-interlace

@gladys That seems to do the trick. Thanks! Would you mind posting it as an answer so I can accept it?

In the video sequence editor you have an option in the properties panel --> filter tab, you can check de-interlace.


text:
What elements go into a good material testing scene
I've been searching a bit for the perfect material testing scene, so I'm curious, what are some of the most important elements in a material testing scene?

It depends on your needs, but in general I would suggest use a shaderball scene: http://blender.stackexchange.com/questions/21807/cycles-advanced-shader-ball, in use: http://blender.stackexchange.com/questions/23913/how-to-create-a-mirror-shader

Make sure you have correct neutral lighting (a diffuse grey (50%)
sphere should render as diffuse grey (50%)).
You need some reflectors to judge reflections.
Maybe you should have an object with a stepped thickness so that you
can see how refraction behaves.
You could also setup additional renderlayers with different lighting
situations.
Maybe a grid on the floor to get the scale right (cm, dm, m)?
A McBeth chart of some sort?
A diffuse and a reflective sphere for reference in some corner?

I think SHED have some nice examples in their blog somewhere...

Not really what I was looking for. Could you be a bit more specific? Also, if you're going to link to a blog, could you link to a specific article? I just don't think it's good to link to a blog and expect someone to actually go through it to try to find something that they don't even know the name of.

So what is it then you are looking for? More specific on what? As for the blog, I just seem to remember that they show some pictures where they test their shaded models in hdri environments. Sorry I don't have the time right now to look it up for you.

I was thinking a bit more information for each of your points, but at this point I think it's good enough.


text:
How to rotate the direction of the curve extrusion by 90 degrees
I'm modeling a ribbon out of a curve to put on a present model.
I'm using the extrude feature to form the actual ribbon.

The issue, is that the curve is tilted the wrong way.

How can I rotate the direction of the curve extrusion by 90 degrees?

I thought for sure I saw a question just like this in the past day or so, let me check.

@HATMAN Could that have been me in chat a few days ago?

Possibly, I'm not sure

This is done using the tilt feature.
In the curve edit mode, press CtrlT. Then simply type in 90 to tilt it by 90 degrees.


text:
Mesh cache modifier bake to keyframes
I have such question. I made clothes & animated them in Marvelous designer, and then using Mesh cache modifier, opened this animation in Blender. And I would like to know, is it possible to turn the data from this modifier into keyframes?

Can you pls provide the .blend file?
There is a way but I need the .blend file to actually understand the problem

You need to Bake Action on selected objects with Transform Cache

Select objects with constraints (I'd filtered it manually with Outliner's search and Object Children filter unchecked).
Rub Object > Animation > Bake action... operator.
Select frames, and enable Clear Constraints checkbox and press OK.

I assume that you have a softbody simulation and now you want to convert the simulation into keyframes.
If this fits then follow these steps
1.export your object as an alembic file
2.after the exportation is complete, open a new project and delete everything in the scene
3.Import the alembic file you just exported and hit play in the timeline. You will see the simulation running in your scene.
4.now select your object and add rigid body to it. Make the rigid body type "active" and animated(checkbox).
5.now with your object selected click on the object menu then rigid body and then click on "bake to keyframe". It might take some time depending on what you are baking
After the bake is complete you will have the cloth physics converted into keyframes. You can now also export it as a fbx file

No no, not softbody. I opened clothes animation from program "Marvelous designer" (file .pc2) with using modifier "Mesh cache". And I would like this animation to become keyframes, and not work from modifier.
I tried to do how you said, but after baking, only the first frame is displayed. I've tried "Bake to keyframe" & "Bake action" but no result.

can you provide the .blend file pls?I could do the work and record it and send it to you.

I seem to have found solution for this situation. If export to mdd, then mesh will turn into keyframes with shapre keys.
And thanks for taking the time & you trying to help.

Your welcome. Glad that you found the solution

@Juliya you mentioned you found solution. Can you explain how you obtained keyframes from cloth simulation file?

I exported mdd cache from Marvelous and in blender I added meshcache, but I still don't see keyframes


text:
Light paths for different Render layers
I have several Render layers in my animation. I need to change value Light paths Max: 25 only for one Render layer, otherwise layer with hair looks bad. But when I change this value, it changes on all layers. I don't want to set such high value for all layers because this will increase rendering time. How to set different Light paths for different Render layers? Or is it impossible to do in one scene?

Have you tried using 2 scenes clone of each other with different render settings and combine them in Compositor?

To be honest, I just found out today that can create several scenes. Yes, I tried to do it now & it worked. Hooray! Thanks for advice. And as I understand it, there is no other method, right? And by the way, which version of new scene is better to use: Link objects or Full copy? I just don't quite understand difference between them.

If you do a linked copy, any change you make to your objects will be passed on to the other linked scenes. However in a full copy, you can freely edit your objects without affecting the other scenes

Now I understood. Thanks a lot!


text:
Fire simulation in 2.82
I made animation in 2.79 & I opened it in 2.82 to render. All effects work (dynamic paint, ocean, particles, soft body), but fire doesn't work. It doesn't even appear in preview window. Also, all fire settings were reset. I found answer how display fire, for this need to change Type of Domain to Replay. But Bake button disappeared.
How to bake fire simulation on Replay? Other types Modular & Final don't display anything even after baking. Or what to do so that fire is displayed & rendered in 2.82 Cycles (and preferably with settings from 2.79)?

With blender 2.82 a new fluid simulation engine was introduced called Mantaflow. So that is the reason your old simulations are not working, you can try using a older blender version.

Thank you for answer. I didn't know about Mantaflow. I checked in 2.81a, fire was able to render as in 2.79. Only unfortunately Denoise node in this version of Blender works worse & blurs all details.
And what does Mantaflow mean? What is its difference from previous engine?

Denoise in 2.81 works perfectly fine, make sure you are using the new denoise node based on the Intel denoiser.
First go to view layer properties and turn on denoising data and go to compositor and add denoiser and connect noisy image, denoising albedo and normal to the denoise node.

I do everything so how you said. But when I compared the same frame in 2.81 & 2.82, I saw difference. In 2.81 is more blurry.

You don't have to bake if you set your cache type to replay. You can simply hit the space and it will start baking in real-time(which means you can see what is happening in the viewport and make changes accordingly). You will have to set it to modular or final to bake. Note that your you can play with a better fps if you bake it with modular or final

In real-time it plays sooooo long. Even much longer than in 2.79. Modular & Final don't work. These types don't show anything even after baking.

what do you mean by so long

When click Play, then fps ~ 2-3. And this is with default settings. It's difficult to make any settings with such low fps.

you will have to pause to make changes. Also, you have to hit the bake button if you are using modular or final. note if you bring the resolution of smoke down you can bake faster even in replay

Modular & Final types don't work. Therefore, I can't bake simulation. And in Replay such low fps always. I created new file, added cube & Suzanne, made Domain & Flow from them & played animation. Fps ~ 3.

did you bring down the smoke resolution

OK, I made Resolution divisions: 6. FPS ~ 13-14. No, this clearly doesn't depend on it. Maybe need to include something in Preferences? I already don't know what to do, but smoke in 2.8 works disgustingly. Or maybe it's bug of 2.8?


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How to duplicate and mirror particle hair on asymmetrical model?
Please tell me, how to duplicate hair on asymmetrical model in particle system & mirror it to the other side?
I made a hairstyle on one side of the head & I want this finished part to appear on the other side of the head, but neither Shift+D nor Ctrl+V work. Also, model is asymmetrical & therefore it wasn't possible to make hair on both sides at once. Model already has weights & is ready for animation, so duplicating the mesh itself & mirror it together with half the hairstyle is not an option.

For symmetrical objects, the hair particles can be mirrored with the menu entry Particle > Mirror. The hair must be selected.  - If the object is asymmetrical this doesn't work but you could convert the particles to hair curves and mirror them with a Geometry Nodes modifier. Then convert them back to hair particles or work with the new hair curves. By the way, can't you make a symmetrical hair cap and use this as an emitter?

Can you please give more details on how to do this?
And regarding hair cap, I simply duplicated part of mesh from finished head with ready weights & therefore it's not symmetrical.

For symmetrical objects, the hair particles can be mirrored with the menu entry Particle > Mirror. The hair must be selected.
This does not work if the object is asymmetrical. But there is a solution:

convert the particles to hair curves. Blender will create a Curves object named Particle System.

then mirror them

in Blender 4.2, you can do this simply in Edit mode. Press Shift+D,Esc to duplicate them. You can use the 3D Cursor (.) as pivot point and mirror the curves by scaling them with factor -1 along the X-axis (SX-1).
in Blender 3.6, the duplicating the curve points in Edit mode does not work. But a Geometry Nodes modifier can do the same for you. Add and apply the modifier to make the changes permanent.

finally, convert the curves back to hair particles (or work with the new hair curves if you don't need Hair Dynamics)

enter the Surface object, usually the hair cap or the head and the UV map in the Curves settings.
switch to Sculpt mode, and use the menu to snap the curves to the surface.
finally, use the menu again to convert them back to a Particle System

Thanks!It works, but not perfect.Firstly, hairstyle changes a little in places where hair didn't fit head.Also need to remove all hair settings before converting, otherwise won't be able to even reduce amount of hair to animate.But if remove all these, hairstyle changes a little again.This can be corrected, although pity it don't remain original.But main problem is that when converting to curves there are too many dots appearing & when returning to particles it becomes inconvenient to edit, and it also slows down hair animation a lot.Is it possible to somehow reduce the number of these points?

oh yes, I forgot about the particle settings. They will be lost and you will have to enter them again at the end. It's also a good idea to turn off Children before you convert the particles so only the parent hair particles get converted. -- The number of points can be reduced by a Geometry Nodes modifier that has a single Resample Curve node in it. The Count setting defines the number of control points.

It works! The number of dots on curves has decreased. Thank you very much for your help!


text:
Wet cloth material on skin
I would like to know how to make wet cloth material on character? How to make folds of fabric that don't touch skin are white, and those areas that come into contact with skin are color of skin?
Here's example:

https://blender.stackexchange.com/questions/78769/how-to-create-vacuum-packaging https://blender.stackexchange.com/questions/125116/how-to-do-vaccuum-sealed-pack-modeling-in-blender/

Ambient occlusion might be able to generate a useful mask

--- Duarte Farrajota Ramos ---
No no, I don't need packaging effect, but nodes for texture. I.e. how to make fabric adjacent to body have other color.
--- Allen Simpson ---
I tried AO, but it doesn't quite give the desired result.

For a wet clothes shader, you need a proximity mask that defines where the fabric touches another object (e.g. body, floor). In the touching areas the fabric becomes quite transparent, in the other areas less so. (For realism, you also want to change the color slightly in these areas, and mix in some noise.)
No wet T-shirt contest but Suzanne! In the bottom left corner you see the reflection from clearcoat
Basically, the shader is just a Mix node feeding the Alpha input of the Principled BSDF node and Clearcoat set to 1.0. In the example, a fabric texture is used to get a better impression of the desired result.
The Noise Texture varies the transparency. This simulates that not all areas of the fabric are equally wet. You can do something similar to the Roughness value.
The Color Ramp nodes are used to adjust the transparency and color of the wet areas that are close to an object.
For a good proximity map, combine a Cloth simulation with Dynamic Paint physics. Then you can use the wet paint mask of the Dynamic Paint as a proximity mask.
meh! I forgot to mark the image count settings of the Image Texture node but you can see it in the top left corner
For the Canvas settings, define a low Dry value like 5 to update the proximity mask quickly.
Make the Brush paint on Proximity with a low Distance of 0.1, for example, but not too low because then it doesn't work.

Now we have everything we need. But there are a few things and pitfalls to consider:

The Cloth Object

will be the canvas for the Dynamic Paint and has the Cloth simulation
for Cloth simulation performance you want to keep the mesh as low-poly as possible but it must have enough geometry to create nice wrinkles.
a level 1 Subdivision modifier after the Cloth modifier will smooth the mesh

The Body and Floor Objects

are brushes for the Dynamic Paint
they are also collision objects for the Cloth sim. If the body object is a high-poly object you can create and use a low-poly version for collision.

Dynamic Paint can use vertex colors or a baked Image Sequence.

since vertex colors require a high number of vertices and they will affect the Cloth simulation, it's better to go with a baked Image Sequence. This requires no extra geometry but a UV map.
the Dynamic Paint modifier should be below the Subdivision modifier to take advantage of the extra geometry to create smooth textures

the Auto Refresh option of the Image Sequence Texture is only for frame changes and does not refresh automatically the images in memory as one might expect when the images are baked!

so the shader will still show you the outdated images even if they have been overwritten on disk.
to update the baked images, you need to re-open the first baked image (e.g. wetpaint0001.png) and then re-enter the number of images of the sequence (e.g. 100) for the Image Texture node in the shader editor.

Bake Order

you need to bake the Cloth simulation first
then the Image Texture Sequence of Dynamic Paint
and finally, fix the Image Sequence Texture as described above in the shader editor

Troubleshooting

if you have baked the physics, don't forget that you need to delete the cache and bake it again after you made changes
if it doesn't work, check the output folder if the images are baked correctly
if the wet effect looks blocky, it may help to increase the texture size. But keep in mind that this will slow down the bake process and requires more memory.
make sure you have the correct order of the modifiers (see screenshot below)
there are 4 different places where you must define the end frame for your animation. Make sure they have all the same value.

End setting in the Timeline editor where you press play
in the Cloth simulation cache settings
in the Dynamic Paint > Canvas > Settings section
and the Image Texture node setting in the Shader Editor

Modifiers
Cloth and Dynamic Paint > Canvas (the order is important). I forgot the Solidify modifier to give the fabric some thickness. Feel free to add it.

Dynamic Paint > Brushes:

Thank you very much for such detailed explanation, it's very informative & useful!


text:
Curved glass reflections in Glass material
Why is Glass material displayed fine on one object, but material with exactly the same settings shows some kind of nonsense on another? For example, glass of car. The one shown above has transparent glass, while the one below is black & has curved glass reflections.
I tried to add Subsurf, tried changing Light path settings, turned off Auto smooth, tried different glass settings, but nothing helped.
And this happens often. Please tell me what it depends on & how to fix it?

Your Glass material behaviour the same for me. Clear Custom Split Normal Data and add Solidify modifier.

In provided blend both materials behaves the same for me.
Anyway ... bottom one seems to be correct from material setup perspective. Glass needs a thickness otherwise cycles thinks it is an "endless" glass volume.

Since you add s thickness like Solidify modifier, Cycles know where glass begins and where ends its depth. But as you can see there is some issue with normal orientation.

Go to Data Properties > Geometry Data > Clear Custom Split Normal Data

I guess, this is result you are expecting from glass material.

I hadn't noticed the custom normals .. I guess they might be a Data Transfer from a more heavily subdivided mesh, for economy?

Yes, this is exactly what I need. Thank you very much for your help!

@RobinBetts Probably ... I'm not such experienced with Normals, I just saw the "crazy" reaction of Solidify, that didnt react on Auto Smooth :)

The simulation of refraction depends on light rays being bent twice. Once on the way into the glass, via a front-facing surface, and once on the way out, through a back-facing surface. Your 'good' glass has thickness, so it works. Your 'bad' glass doesn't.
No thickness:

With a Solidify modifier: (No rim. 'Fill' unchecked, so as not to bother with normals interpolating over the rim walls)

If you want a rim on your glass, you will have to bevel it too, to sharpen the interpolation of normals from rim to surface.

It worked! Now glass looks like it should. Thank you so much!

@Robin Betts Since your images are more illustrative ... if you extend your answer about Clear Normal Data info ... I'm ready to delete my answer :)

@vklidu IMO your answer is just fine! (UV'd). I didn't clear the normals, because the only distortion I got was from the interpolation to the rim of the Solidify modifier. So my way was just to solidify without the rim, which can't be seen, until the OP rolls down the windows :)

I know ... I just that both answers are speaking in general about same thing ... I wanted to keep it cleaner, but OK. I still live in an illusion we are creating a "cookbook" where people can find solutions for their repetitive issues ... but it is an illusion ... we are still answering the same questions. Even for me (after a few years here) it is almost impossible to find same (already asked) question ... so instead of spending time on searching of dupli, we creates new one. Grrr

Yup. maybe I should just have left the 'rim' point as a comment on your answer, and not posted. You were first, and accepted. I'll look out more carefully in future.

Forget it :) Leave it as it is. I like your screens here :)


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How to Set a Property Value in Blender Game Engine?
How would I set a property value with python in the Blender game engine?

Here is one way of setting the property value of a game engine object (which has an int property by the name 'upkeycount')
I have setup the following logic on a cube object
Sensor:Keyboard('UPARRAOWKEY') <--> Controller:Python(increment_up_count.py) <--> Actuator('upkeycount')
and following is the code for increment increment_up_count.py
import bge

cont = bge.logic.getCurrentController()

sensor = cont.sensors['UPARROWKEY']

if sensor.getKeyStatus(bge.events.UPARROWKEY) == bge.logic.KX_INPUT_JUST_ACTIVATED:
    owner = cont.owner
    upkeycountAct = cont.actuators['upkeycount']
    value = owner.get(upkeycountAct.propName) + 1
    upkeycountAct.value = str(value)
    cont.activate(upkeycountAct)

Few variations of the above code can be found at https://gist.github.com/satishgoda/5682945

There is also the Python API for setting properties directly. Here's the example satishgoda used but without using a keyboard sensor, or a property actuator:
from bge import logic, events

def set_property(cont):
    own = cont.owner

    key_status = logic.keyboard.events[events.UPKEY] == logic.KX_INPUT_JUST_ACTIVATED

    if not key_status:
        return

    own['prop_name'] += 1

Replace own['prop_name'] += 1 with
own['prop_name'] = own.get("prop_name", 0) + 1

if it doesn't have the property by default, maintaining the same indentation as before.
Here is the latest Python API for Blender. It will point to the most up-to-date version.

The blender game engine's objects' properties are organized like a dictionary. So you can use the interface to set it, I am sure there is a function to do it similar to the __setattr__ built in and you can do this:
GameObject["newprop1"]=1
GameObject["newprop2"]="Hi there!"
GameObject["newprop3"]={"A":"B"}
GameObject["newprop4"]=[1,2,3,4,5]
GameObject["newprop5"]=True
GameObject["newprop6"]=3.14156

I think lists and dictionaries don't always behave as expected since properties aren't inteded to be used like this, updating and changing is difficult afaik but you can still use them otherwise and if you need to change them and run into difficulties you can always create temporary local copies, change those and then reassign the property with the new value.
The others should work fine though.

The way to call or use property values in the Blender Game Engine is the same as in each of the other render engines. However, all of the properties have different names. For example, the rotation of an object is found by calling object.rotation_euler in Cycles and Blender-Internal, but object.worldOrientation in the Game Engine.
As far as I know, the 'hover over' trick to find property names unfortunately doesn't work with the Game Engine (it will give you the same values as Cycles/Blender-Internal). I haven't yet found a single resource that covers all of the Game Engine properties, but I imagine the Blender Wiki Documentation would be a good place to start.


text:
How combine hair particle layers?
Please tell me how to copy hair lines in Particle edit? Ctrl+C & Shift+D don't work. Or is there no such option in Blender? Then maybe if duplicate layer & change it how need, then how then combine these 2 layers? Setting up many layers for animation is very inconvenient, so could you tell me how to combine layers with the same settings?

I think there is no such option for the (old) particle system. Which Blender version do you use? The new hair curves (Blender 3.3+) can be edited and duplicated. You also can convert particles to curves and vice versa. -- By "layers" do you mean 2 particle systems on one object?

I use v4.2 & yes, 2 particle systems on one object. I use particle system out of habit & I thought that this new Hair curves is the same thing, only more conveniently organized. And I'm not sure if it is possible to animate through Hair curves & therefore I still use particle system.


text:
How to make mask for material with Volume in compositing?
How to make mask for material with Volume in compositing? I need to change color of clouds, but in scene doesn't produce desired result, so I tried to do it in compositing, but neither ID mask nor Cryptomatte work with Volume. Please tell me how to make that it work?

I'm not sure if I understand correctly what you want to do. You have clouds made of a volume, and they have a volume material - which supposedly gives them their color? So why don't you just animate the color of the volume material...? Or am I missing here something?

Yes, there is cube with Volume material as clouds, but color in scene itself for these clouds can't be set up properly. I thought that this could be fixed in compositing, but as it turned out, Pass index doesn't work for Volume materials. Compositing doesn't see it & doesn't allow changing color or making glow or anything else. Maybe there is a way to make compositing work with Volume materials?

Sorry I don't understand why "color in scene itself for these clouds can't be set up properly"? Since you don't show how it is set up, I don't see a reason why it should not work to animate the material color.

Background affects color of clouds & attempts to change it don't lead to desired color, or volume becomes less visible. The only option is to adjust color in compositing.

Do you know the phrase "a picture says more than 1000 words"? I still have no idea what the problem is, what it looks like now and what you want it to look like.

It doesn't matter how it looks & how it should look, because this problem is not only with clouds, but with all objects that have volume materials. And so question consists in the fact that, how to make it so that in compositing it would be possible to make mask for volume materials, so that these materials could be changed in color, made glow or something else?


text:
How to make glass reflect illuminated objects but glass itself doesn't reflect light source?
I want to make heat distortion effect in Cycles, but it reflects light source. If move effect on another Render layer & exclude light, then it reflects objects behind without light. How to make that this material not reflect light source, but to reflect objects behind with light on them?

Try going into ray visibility and fiddling with the settings

Thank you so much! It helped to uncheck Transmission.


text:
Seamless Procedural Texture in Polar Coordinates
I've written a Cycles node tree to convert rectangular (X,Y) to polar coordinates (R,theta) as the basis for a procedural texture with radial symmetry.
However, there is a seam in the texture where theta jumps in value (-pi -> pi or 0 -> 2pi).
What are some of the techniques for eliminating this seam? I have found one method that uses a blended overlap region. Are there others?

Have a look at this: http://blender.stackexchange.com/a/45169/7777

That's useful for textures with regularity. Thank you for including the details of the node groups for the cylindrical and spherical projections. I will compare them to the node groups I created.
I plan to use Noise, Voronoi, or Musgrave textures that do not repeat like the chevron in your solution. I expect the discontinuity at -pi (or 2pi) will be visible.

Yes, when the texture is not tiled you will have a seam.

I am curious as if you have found a solution to this issue...

@astrogeek More specifically, would you mind showing us how you achieved the blended overlap region or linking the solution you found? I'm having the same issue.

@VilkoL I haven't gotten back to this issue yet. I'm currently hiding the seam by using a texture with a really large scale (i.e. small-scale features) so the seam is largely mixed in among the many variations in the texture.
I found this wonderful page http://paulbourke.net/texture_colour/edgeblend/ and intended to use his algorithm. The middle-to-last part of the page gets into the details.

Something like this may help : https://blender.stackexchange.com/a/119564/29586

@ Rich, that page poses a great solution. Thanks for the heads-up so many years after my original post.

Sine and cosine pair to bend an axis into a loop.
I'm using a sphere to represent to polar coordinates but the math applies regardless.
This will use up 2 axes of your procedural texture for the Theta component.

Important to have the theta properly in radians. here it's done by, mutiplying it by 2π.


text:
Uses for the Location vector of the Particle Info node?
What can the Location values of the Particle Info node be used for? It seems to provide control of something like color or texture of particle instances, but I can't seem to implement that idea.
Can it be used in conjunction with the Point Density texture node?

Please show an example of your work to clarify your question.

Particle Distance to Some Particular Point

The particles are colored differently within a certain distance to a given point P0.  Emission Shader. In the user ortho view is the cylinder with a particle system. The white torus has that same point P0 as center.  Image above.

Cycles Material Nodes calculating distance and employing color ramp.  Image above.
Click image above to see larger image.
The OP has asked about Textures Controlling Particles Systems.
This is a quick piece of information for further research.  The two columns are of the Particle Texture Settings which are visible only in Blender Internal Render Mode. Cycles will [not] show the same info, yet will be influenced by the textures as well. You can switch back and forth as [interesting] as this might seem.  The three yellow arrows emphasize Texture Panel Purpose, Mapping, and Influence areas.  This is not a tutorial on the topic.  I use two columns for the same settings out of edit convenience and readability convenience.

With a more complicated frame change handler and Python anything is possible. Same comment for BAN - Blender Animation Nodes.

wow!  your using my favorite font!

@X-27 How can you be sure?

Eurostile LT ExtendedTwo is an unmistakably awesome font - it can't possibly be mistaken for anything less awesome.

Nice example, atomicbezierslinger. Material color based on distance is something I had in mind. I undertstand the geometry of the emitter and the use of P0.
What I don't understand is relationship between the objects in the scene and the Material NodeTree you illustrated. Which object holds Material.023? Is it the torus duplicated with the cylinder's particle system? Is it the cylinder itself?

I tried both cases and discovered that the duplicated object should hold the Particle Info node. That kind of blows my mind since the duplicated object does not have a Particle System.
Is there a way to connect the Particle Info to a Point Density texture?

All objects have a particle info attached to them. If they are not part of a particle system then they might have particle index 0. Thus particle info is a convenience for objects without a particle system for uniformity of software. This happens often in software, uniformity with default values. Yes textures can control the density and placement and color et cetera of particles. Try searching and see what you find here at BSE. If you find nothing within 48 hours then please send a message..... See above edit.

Thank you again, atomicbezierslinger. Your explanation makes a lot of sense from a software perspective. I will continue to investigate!


text:
How to assign colors to Point Density based on data values?
I have a file containing approximately 900,000 x,y,z data points, each with a list of physical values at that position (temperature, density, chemical composition, etc.)
I have written a Python script to create a mesh and add a vertex at each x,y,z position. Then I added a cube to the scene and added an Emission volume shader that is fed by a Point Density texture. This produces a visualization of the distribution of points. I can write a Python function that converts the physical values to color values.
How can I assign these colors defined at the x,y,z data points to the Emission volume either directly or through the Point Density texture?

I've often wondered if there's a way to craft a smoke cache to do this sort of thing..

I wanted to announce that the latest builds now have an updated Point Density node that can use Vertex Color, Vertex Normal, and Vertex Weight values of a mesh. This functionality was developed after 2.77 was released, but I have been told the new Point Density will be standard in 2.78.

The following script will generate a vertex color layer and assign a color for each vertex coordinate. Since you have a data structure with a color assigned to each vertex, and the vertex's coordinate, you can it to assign colors to each vertex.
The code is not straightforward, since the vertex color layer does not assign a single color to each vertex, but rather a color for each mesh loop. A single vertex can be a part of several loops, and thus have several colors. In a cube, for instance, each of the 8 vertices has 3 vertex colors.
This is why the find_loops_by_vert_co function takes in an object and a vertex coordinate, and returns the list of all loop indices that include a vertex with the same coordinate.
When iterating over the vertex coordinates, this function is called and assigns the desired color to each of the relevant loops. I'm using a specific data structure to include coordinate and color data. You'll have to adapt this script to match your own data structure.
import bpy

def find_loops_by_vert_co( o, co ):
    verts = o.data.vertices
    loopsInCo = []
    for poly in o.data.polygons:
        for i in poly.loop_indices:
            vCo = verts[ o.data.loops[ i ].vertex_index ].co[:]
            compare = [ round( e1, 3 ) == round( e2, 3 ) for e1, e2 in zip( vCo, co ) ]
            count   = len( [ e for e in compare if e ] ) == 3
            if count: loopsInCo.append( i )

    return loopsInCo

o = bpy.context.object

# Create a new vertex color layer
o.data.vertex_colors.new('Heat')
heat = o.data.vertex_colors['Heat']

coos2colors = [
    { 'co' : (1.0, 0.9999999403953552, -1.0),                  'color' : ( 0.5, 0.25, 0.25 ) },
    { 'co' : (1.0, -1.0, -1.0),                                'color' : ( 0.1, 0.6,  0.3  ) },
    { 'co' : (-1.0000001192092896, -0.9999998211860657, -1.0), 'color' : ( 0.9, 0.1,  0.2  ) },
    { 'co' : (-0.9999996423721313, 1.0000003576278687, -1.0),  'color' : ( 0.5, 0.8,  0.0  ) },
    { 'co' : (1.0000004768371582, 0.999999463558197, 1.0),     'color' : ( 0.4, 0.4,  0.9  ) },
    { 'co' : (0.9999993443489075, -1.0000005960464478, 1.0),   'color' : ( 0.1, 0.1,  0.6  ) },
    { 'co' : (-1.0000003576278687, -0.9999996423721313, 1.0),  'color' : ( 0.5, 0.5,  0.0  ) },
    { 'co' : (-0.9999999403953552, 1.0, 1.0),                  'color' : ( 0.5, 0.25, 0.25 ) }
]

for d in coos2colors:
    co, color = d['co'], d['color']

    vIndices = find_loops_by_vert_co( o, co )
    for vi in vIndices:
        heat.data[ vi ].color = color

You can use the vertex color layer in Cycles by using the Input --> Attribute node and plugging it into an Emission shader's color input.

Thank you for the example code on Vertex Colors. However, I cannot create faces out of the input vertices because the data represents a 3-d point cloud, where each point represents a single sample of the physical values. The vertices are scattered throughout the 3-d volume. If I created a set of faces out of the outermost vertices, it would hide the remaining vertices on the volume's interior.
I was specifically looking for a method to color the Point Density texture in the cube object that surrounds the cloud of vertices derived from the data.

Ah, shame. Hope someone here will figure out how generate, read and use a 3D texture for point clouds.


text:
Issues installing Oscurart addons
I am attempting to install the Oscurart tools as found in https://github.com/oscurart/BlenderAddons. I tried other sources first but no luck with them either.
I have Blender 2.76 2015-Nov-04 on a Mac running 10.11.3
After downloading the zip file from GitHub I used install from file in the Add-ons pane of Blender's User Preferences to install the zip file. I don't get any notifications from Blender that I see as to a result but it goes back to the Add-ons list.
The files do all appear in ~/Library/Application Support/Blender/2.76/scripts/addons.
Quitting Blender and restarting it even with all three support levels selected and All categories the tools are no where to be found. I've looked at all the other answers related to installing addons I can find and have come up empty.
Does anyone have any clue what is going wrong?

The zip contains many add-ons, in this case the Install From File feature in User Preferences won't do the right thing. The zip on github isn't intended to be used with Install from File directly. Blender will unpack the content of that zip to a folder inside your addons folder, called Blender Addons-master.
Solution
First you should extract the zip to somewhere on your local disk, then use the Install from File option to navigate to that directory and pick the add-on you wish to install.
You know an add-on was added to Blender's collection when straight away after that procedure the add-on is shown in the panel -- waiting for you to enable it (it will be unticked until you do).
edit
One might more accurately describe that collection of add-ons as a collection of add-ons and scripts. Some of the Python files in the collection can't be installed as add-ons. Blender expects scripters to add a bl_info description to their code if they want to make the script available as an add-on for installation. Without bl_info Blender won't be recognized them. Scripts that don't have a bl_info can usually be run from Blender's text-editor, and they may or may not have any UI.

This mostly worked. Some of them just refuse to install no matter what. Looks like part of installing them involves converting from python to python bytecode, perhaps it's time to learn how to do that conversion and see if I can help the precess along in some way.

So there is a trick that will get more of the addons to install. For any addon that doesn't install the normal way use python to compile it in Terminal. Add those compiled files to the _pycache_ folder in the addons folder in application support. Then start Blender and install the original files. Provided they have the proper bl_info block at the top they should install. Not all of the Oscurart addons have this block so some still won't install but its a step in the right direction.

Manual installation of oscurart on linux:
Create a folder in usr/share/blender/addons named /oscurart_tools
Then copy the seven furnished .py files in that folder
Restart blender eventually (I'm unsure if this is compulsory)
the add on will appear.


text:
Set Vertex normals to vertex color in Python
How do i set the vertex color to vertex normal for all vertices of an selected object?
My approach here somehow prints only a few vertices and spares out the rest :(
How can i fix that and include ALL other planes, too? (see images below)
import bpy

current_obj = bpy.context.active_object
mesh = current_obj.data

if mesh.vertex_colors:
    vcol_layer = mesh.vertex_colors.active
else:
    vcol_layer = mesh.vertex_colors.new()

print("*"*40)

for poly in mesh.polygons:
        for loop_index in poly.loop_indices:
            loop_vert_index = mesh.loops[loop_index].vertex_index

            #color = [1 , 0, 0]

            #vcol_layer.data[loop_index].color = color

            #vcol_layer.data[loop_index].color = mesh.vertices[loop_vert_index].normal
            color = mesh.vertices[loop_vert_index].normal
            vcol_layer.data[loop_vert_index].color = color

            print("painting vert",loop_index, "to color ", color[0], color[1], color[2])

mesh.vertex_colors.active = vcol_layer

mesh.update()

Outcome for a sphere (paints only 1/4 of vertices??):

Outcome for a foliage-mesh (all planes are joined into one mesh)
Still paints not all vertices????

Please help me out, how to include all vertices :)

So are you trying to make a normal map?

yes, but stored in the vertex colors

You must set vcol with loop index, not vertex index, because those are loop data (i.e. one color per face corner):
import bpy

current_obj = bpy.context.active_object
mesh = current_obj.data

if mesh.vertex_colors:
    vcol_layer = mesh.vertex_colors.active
else:
    vcol_layer = mesh.vertex_colors.new()

print("*"*40)

for poly in mesh.polygons:
        for loop_index in poly.loop_indices:
            loop_vert_index = mesh.loops[loop_index].vertex_index

            #color = [1 , 0, 0]

            #vcol_layer.data[loop_index].color = color

            #vcol_layer.data[loop_index].color = mesh.vertices[loop_vert_index].normal
            color = mesh.vertices[loop_vert_index].normal
            vcol_layer.data[loop_vert_index].color = color

            print("painting vert",loop_index, "to color ", color[0], color[1], color[2])

mesh.vertex_colors.active = vcol_layer

mesh.update()

However, since you are merely using vertex normal, it’s much simpler (and efficient) to loop directly on loops - and vcol are clamped to positive numbers, so you'll likely want to encode negative values with something like col = nor * 0.5 + 0.5:
import bpy
from mathutils import Vector

current_obj = bpy.context.active_object
mesh = current_obj.data

if mesh.vertex_colors:
    vcol_layer = mesh.vertex_colors.active
else:
    vcol_layer = mesh.vertex_colors.new()

print("*"*40)

for loop_index, loop in enumerate(mesh.loops):
        loop_vert_index = loop.vertex_index

        #color = [1 , 0, 0]

        #vcol_layer.data[loop_index].color = color

        #vcol_layer.data[loop_index].color = mesh.vertices[loop_vert_index].normal
        color = (mesh.vertices[loop_vert_index].normal * 0.5) + Vector((0.5,) * 3)
        vcol_layer.data[loop_index].color = color

        print("painting vert",loop_index, "to color ", color[0], color[1], color[2])

mesh.vertex_colors.active = vcol_layer

mesh.update()


text:
Freestyle External Contour has Large Gaps. Error Related to Topology?

Large Gaps appearing in external contour. I've disabled any modifiers and have troubleshot the issue extensively using other "gap fix" procedures & recommendations. Error appears to occur at very acute angles, but line-render isn't tied to occluded freestyle edges. Error somewhat affected by rotation of object

Related: http://blender.stackexchange.com/q/3735/599

Already attempted methods mentioned in issue: http://blender.stackexchange.com/questions/3735/why-do-freestyle-outlines-occasionally-have-gaps
Did not solve the problem.

Do you have the Face Smoothness option enabled?  Do you also have the same problem if you change the camera from perspective to orthographic (and vice versa)?

Face Smoothness is enabled.
Problem occurs in both Ortho and Persp.

What is the shading (either Flat or Smooth) in the problem area of the mesh data?  If the Smooth shading is used, do you also have the same problem when the shading of the problem area is changed to Flat?  What happens if you disable the Face Smoothness option?  I guess this issue is caused by an unknown bug related to line visibility.

The problem appeared at a point when some edge-hardening was applied. Smoothed, both with and without Face Smoothness, produced better results, but neither was usable. Additionally, I added more geometry around the tail-fin which helped, but did not solve the issue.
I ended up going with a combo of all smooth shading + Face Smoothness disabled + Geometry > Backbone stretching. It helped hide the small gaps and didn't create any large ones. Did lead to a lot of errors extending outside the silhouette, but not too many within. This is obviously a work around & not a proper solution

I ran into a similar issue, in my opinion this is a bug ocurring when working with larger geometries. Try scaling your geometry down (dimensions below 100 units) and try again.
For bigger geometries sometimes whole lines or part of lines (always when crossing with hidden lines as seen from the camera) are disappearing, this goes away when simply scaling down. See the screenshots below.

I've file a bug report here, including a testfile: https://developer.blender.org/T49479
Update: According to the bug report, this bug has been fixed end of December 2016 and should not occur anymore in newer versions of blender.