text:
how to just "reference" a nodegroup in shader editor instead of copying via python?
I have a material setup like this:

I want now to copy this material via python, and change the texture images (so these should be real copies) but the nodegroup should be referenced (so all copied materials should use that one nodegroup instance).
I copied the material like this:
def copyObjectFromSelectedWithTemplateMaterial(newObjectName, newMaterialName, noOfObjects):

    orig = bpy.context.selected_objects[0]
    copy = copyActiveObject()
    copy.name = newObjectName
    copy.location.y = orig.location.y + 2 * noOfObjects

    mat = bpy.data.materials["TemplateMaterial"]

    # problem: node group is not linked to original...
    copy.active_material = mat.copy()
    copy.active_material.name = newMaterialName

    bpy.context.collection.objects.link(copy)

    return copy

def copyActiveObject(): # real copy, not linked copy

    orig = bpy.context.selected_objects[0]
    return bpy.data.objects.new("my new object", orig.data.copy())

Unfortunately i don't know how to make the nodegroup just a reference...so just the opposite of clicking the button "make single user". Hope it is understandable.

You can't make the node group, as shown, "just a reference".
You can reuse the entire material. That will be reference counted, but if you change the material, every user sees the change.  That's when "make single user" comes into play.  That function copies the original thing and gives it a new name of the form oldname.xxx where xxx is a 3 digit number with leading 0s.
The closest you can come is to make a node group from the nodes. In python you do this with bpy.ops.node.group_make() This creates a new node from the selected nodes that can be used by multiple users.  But again, if you change the nodes inside the group, every user of the group will see the change; and you need "make single user" on an instance to be able to make a copy that stands alone.
This example is taken from "Create a node group from an existing tree" on devtalk:
active_area = context.area
active_area_type = active_area.type
active_area.type = "NODE_EDITOR"
active_area.ui_type = "ShaderNodeTree"
context.space_data.node_tree = your_tree_name
bpy.ops.node.group_make()
active_area.type = active_area_type


text:
how can i use vertex weight value in shader nodes?
I found this answer by Nathan: Weight paint in cycles nodes?
This is exactly what i want to do: use vertex weight value for "changing colors"/"use in shaders".
Nathans answer seems to be the solution, but...i don't understand it and i don't know how it works. Can somebody give me a step by step tutorial how to do it?

I'll leave it for a while to see if @Nathan is around.. that's only polite :). In the meantime, I assume you've already seen this

maybe you should put a comment under his answer and ask for some precisions?

If it works „only“ with GN as Robin wrote - I am happy

…but I didn’t get it work until now…but fighting

@moonboots: that's why i didn't want that comment under Nathans answer. You can read yourself what he wrote....

@RobinBetts: I think you can answer now. I am pretty sure he has seen my question and because of his comment i think he thinks i am not worth to get an answer ;)

@Chris  I'm sure it's nothing personal.. Nathan is probably looking for a specific query to answer: with the description already given, it's hard to know what to clarify further... there are quite a few possible gotchas. In the mean time, here's a blend file

I got it working now with your geometry nodes solution ;) my main problem was - it works only in cycles and i always tested with EEVEE ♂ but MANY THANK YOU AGAIN AND AGAIN for your blend file. -> good idea to write the explanation in the text file, especially for me, who doesn't know what I did last week...

ok, i now try to understand Nathans solution - because it works in EEVEE. Rendering in cycles needs days for what i am looking for....

@RobinBetts: got it working now. Thank you!!!!

Hello and welcome. While files, images, and external videos or links may be helpful additions they should not be the only way to obtain information about your issue...  And it seems you missed an opportunity to answer your own question?

@Chris I'm only now seeing this question-- sorry I didn't respond here.  Robin Betts is totally right, it's nothing personal, it's just hard to answer "what am I doing wrong" without knowing what exactly you're doing, and especially hard to do so via comments.  GN indeed is a better solution now, and it sounds like you got the original method figured out anyways?

Yes, no problem, Robin helped me

My knowledge at that time was very limited and for me as a beginner that answer was hard to understand. Fortunately Robin did provide me the blend file so I could figure it out.

With the geometry nodes it is now possible to use the weight almost directly (however I believe the "Vertex group" node will be added to the shader nodes some day to make it straightforward). Just add geometry nodes modifier to your object and use "Capture attribute" node to make the weight available as an attribute in your shader. Below I have "w1" vertex group and "weight" attribute injected by geometry nodes. Then use this new attribute in the shader.

Thank you so very much! Really appreciated! :-)

All it takes is geometry nodes with an input socket connected directly to an output socket. In the GeometryNodes modifier, you can set input to your vertex group, and output to an attribute for access in your shader.

Much simpler than the accepted solution

I've been struggling to find a quick workaround for this. For anyone using Blender 4.2, what I did was create a vertex group named Group, then created a GeoNode where I pass this attribute to a GeoNode output named GroupOut. I can then use this in my Attribute node within my Mix Shader.

This is the most logical solution

source: Stack Exchange

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

sort: votes


text:
Is there any way to reverse triangulation in Blender 2.91?
I have a lowpoly character model that I've been working on/off for years and I'm finally reaching a point that's nearing completion. I'm experimenting with a new rigging method for the hip/thigh flex, but the mesh is becoming super jagged when twisting the leg, due to the leg topology's automatic triangulation. I can manually add in new edges to have a forced triangulation to go the other direction so that the leg twists more smoothly, but it makes selecting edge loops more tedious as a result. If I were to dissolve these manual triangulation-cuts, the mesh automatically goes back to the original triangulation.
Is there a way to change the direction of a polygon's triangulation via edit mode? Like say, changing it from [/] to [\] without having to manually add in a cut in between.
I know that there is a triangulation modifier, but I only need it for a specific section of the mesh, not the entire model.

Like this? https://docs.blender.org/manual/en/latest/modeling/meshes/editing/edge/rotate_edge.html

So far none of these suggestions are for what I am looking for. All of the polygons are quads, and I want to keep them as quads so that it's easier to edit the vertex group/weight paints with selected edge loops, as well as to better keep track of the topology when manipulating the rig. The automatic triangulation has everything become jagged when I rotate the limb in one direction, and I have to manually convert the quads to tris in order to better keep the smooth shape that I need when twisting this limb. Also, I need to stay in 2.9 because 3.0 patched out my modeling method.

I no longer have 2.91 installed but it may be worth a check.
Go to Edit mode and select all the polygons you want to go from triangle to quad.
Then go to Face/Tris To Quads

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


text:
UV Maps rendering with 90 degree skew
I'm a 3DSMax head from way back adopting Blender as my tool of choice. For the most part, I'm bumbling through, but have one strange issue.
When trying to UV map a very simple object, I've been using the Project From View tool using orthogonal viewpoints, but what I see in the UV Map editor is not reflected in the viewport preview or render. It seems to be skewing by 90 degrees, or swapping U with V. Here's a screen snap:

The selected face should have 7 or so boards running crossways, but instead it has 2 boards running lengthways. What shows up in the viewport is the bottom left corner of the image. The vertex coords also seem nonsensical:

I'd expect to see a consistent Y value for both verts, and a low X for the left vert, then a slightly higher X for the right vert.
I'm not sure the shader is the issue, but just in case, here's the shader I'm using for the material:

Nothing fancy. I've tried playing around with the rotation in the mapping node, and I can get it to look okay on the top face by rotating 90 degrees around Z, but I can't get the front face to do anything but stretch. I've also tried deleting and recreating the UV map from scratch.
My best guess is that I'm doing something silly, or I've missed a vital step - is anyone able to better enlighten me? Thanks!

You need to switch your Image Texture node from Box to Flat, otherwise it won't project the island on the correct axis (from what I understand it looks like the Box option will unwrap 90° on Z compared to a default top Project from View):

Outstanding, that's fixed it! Much appreciated.


text:
Do I need to save the file so that I could edit my video sequence again?
I've already rendered it and got the output video but I need to edit it again. Can't find the file to edit the video.

Yes, you need to save your blend file through the file menu, then save. Blender has asked you to do so at least when you want to quit the program. When you didn't save that as well, your cutting work is lost and you have to start all over again...
The blend file contains all the sequences you put in the VSE. And the video footage itself needs to stay on your file system as well (at least relatively to your blend file, there are options to use no absolute paths).
So when you want to keep working on your cuts just open the blend file again and then switch to the VSE view if needed.
You will have everything explained in detail in the very helpful tutorial from Mikeycal Meyers on YouTube btw...


text:
Edge loop is acting like a Seam when I unwrap UV
I made seams at the top and bottom edges of the cup but when I unwrap my image it gets cut by an edge loop in the middle of the cup. When I try deleting the edge loop it deletes the whole structure of the cup. Any suggestions?

What method are you using to unwrap it? Do you know what Edge Collapse is? and are you moving the Edge Loop after applying the texture? Ctrl [E] Clear Seam would indeed remove edges from being marked as seams if that's what happened. I wonder if there's something else going on here....

I selected every face I wanted mapped within the seams ( Ctrl L ) and went to ( U > Unwrap ) and that fixed the issue. Thanks anyways!


text:
How to UV unwrap MULTIPLE image textures on top of one another?
I have a package label with a background illustration that I'm trying to emboss so I decided UV unwrapping the label design into separate layers and onto the bottle "panel" would be the best option only problem is up until right now I only know how to uvwrap ONE image onto ONE surface at a time.
I've tried creating a new UV map in the data panel and adding the second image texture to it's material but that hasn't worked.

The top left image is the first image text and the bottom right is the one I'm trying to unwrap on top of it.

add an uv node and select the uv which you want to use and after you can combine them with mix rgb node being the factor input the alpha of the image that is going over


text:
How do I get the inch measurement around this cup?
In the scene panel I've selected Inches as my units but I get this 463thou symbol instead. Anyone who knows what I'm overlooking, let me know. Asking for a friend.

Related https://blender.stackexchange.com/questions/1674/how-to-get-selected-edges-length

Thousanths of an inch.  eg 500thou is 500 / 1000 or half an inch.  Not sure if there is a way to put it 0.5 inches mode.

I think once it goes below 1" it automatically reads thousandths. One thing that could be done is turn units back to None. This issue seems to have been fixed in 2.8 ,but doesn't help in 2.79.
None in 2.79

Inches in 2.8


text:
How to add an Image to a plane that has a boolean modifier applied?
I merged two plains so I can later rig it into a paper folder animation. I used the boolean modifier to unite the two plains. When I go into edit mode the two plains can still be selected individually so I then mapped an image onto one of the faces and the image shows up on the other face too. I haven't made any seams since the plains are still individual units inside edit mode. Any suggestions?

Thanks in advance.

I'm not 100% sure it's clear from the questions what your aim is.
Asuming you'd like more control over how images are displayed on the final object I'd go with one of two options:

Apply the boolean modifier and work with separate faces in Edit mode
Use the same material to both planes (bool operands) but have different UV mappings for them, so that you can use separate areas of your image to texture the final united plane.

In the example below I did this to both planes with the same image texture applied (same material). However, one plane has UV square on the left side of the image while the other plane has UV on the right side.
You can hide the second plane and the final object would still look the same.
You could do different things then:

Shrink one of the UVs to a pixel sized square and locate it over the needed color to have a mono-coloured part

OR

Scale UV by -1 to reverse the mirror effect you have on your screenshot.

Hope this helps.


text:
How do I fit label precisely around bottle, specifically the circumference?
I plan on wrapping a label around this bottle but the label gets distorted everytime, so I've concluded I need measurements to match. I've thought about making edge loops to get a specific height when making a selection and as for the circumference I can only think of counting all the faces and multiplying length times that. Am I on the right track? Let me know if there's a more effective way of achieving this.

To unwrap a cylinder in correct proportion:

Cut a vertical seam where you want it
Set an orthogonal view (poles or equator.. here, equator)
In edit mode, U unwrap  with 'Cylinder Projection' and settings as shown..

Oddly, in the 'Radius' field, entering pi*radius

.. which  doesn't make sense to me .. but there it is...

I am very confused about both the question and the answer. Can anyone elaborate?

I interpreted the OP as being about how to generate a UV map for a cylinder in such a way that, if you use it to map a flat image of a label, it winds up on the surface of the cylinder without non-uniform scaling, or distortion.


text:
How do I wrap this label on cup?
The front view is almost straight but when I turn the cup the label gets distorted vertically. Is this because of the mesh being curved? Also I accidentally unwrapped the inside faces of the cup, how do you undo this? I'm new lol

you dont have to worry about accidentally unwraping the inside of the cup, just scale it down in the uv editor and shove it somewhere out of the way. if you need the inside, then just unwrap it again.

first download this addon https://github.com/Radivarig/UvSquares to install it open blender and go to file, preferences, addons, install from file and seek and select the zip file that you downloaded and then click open-accept and then check the the lithe box that will appear when it loads and then save user preferences, then see how to use it with this pictures... and dont forget to scale it to fit it well in the whole uv map area.

Finally, I've been digging everywhere about this issue. Thank You!

@JuanIgnacio De Nada xD


text:
Animation Node Installation Error
Blender says I need to unistall prexisting animation addons before it can let me download the one by Jacques. Which one of these add-ons could it be referring to?

Animation Nodes only wants you to remove other version of Animation Nodes currently installed. So just uninstall/remove any other version of Animation Nodes before installing it. So, leave those addons as is.

The only node I have is the node wrangler and that one cant be deleted. Blender only says it wants me to remove other versions of animation nodes when I install the Node Animation windows zip..maybe it's the zip file?

@JuanIgnacio What you need to do is go to the addons directory in your OS and remove any folder related to Animation Nodes. Blender may not recognize such folders as addons by AN will.

I went into the user preferences panel and into the Add-ons directory and looked through all those "Categories" and none have the option of being deleted. I've gone through them twice..

@JuanIgnacio As I said, if Blender can't see it doesn't mean it doesn't exist. You have to manually go to the Addons Folder in /2.80/scripts/addons/ or where ever addons are stored in your system and delete any folder by the name Animation Nodes.

This page describe the possible paths where addons can exist. Go over them one by one and remove the folders related to Animation Nodes. Makes sense?


text:
How can i use custom attributes in geometry nodes?
How can i use custom attributes in geometry nodes?
If i have a custom attribute, is there a way to use it in geometry nodes and how do i do that?

You can use custom properties in GN like this:

create a custom property

add a driver like this

Click to enlarge
to your geometry input value:

result:

Nice. Still feels a little bit convoluted even though it does the job. I hope the Object Info node will be expanded at one point to let users pick custom properties, or even regular metadata on the object on which the GN tree is placed, like its name.

could you explain/update the question with the new nodes ?
I can't find a way to add the driver to the geometry input value...

please ask a new question with a link to this question. I answered a lot of question here on Blender SE and i simply cannot update all answers i ever gave for every new Blender version. I hope you understand that.


text:
rigging problem - why does the rig behave like it does?
I am a rigging noob and i tried to rig this simple setup here:

Just 3 bones, nothing special, last bone has IK.
The only "special" is, that the bones are limited to rotate around z.
The IK has target to the cube, which describes a simple circle.
Why is the rig behaving that wild!? In my opinion it could simple stay in on shape and just rotate? So obviously i made a total dumb mistake here...

I think it doesn't know how to bend at a certain point so it needs a pole target to help it, that's the function of the the pole target

Ok, thank you, i will try that…

I think your problem is that you haven't created a pole target so at some positions there is an ambiguity on how the bones are supposed to bend. Create a second empty, parent it to your target empty, and choose this second empty as the pole target of your IK bone, here is what it gives:

You are my hero


text:
How to overlay a green color on the right of my animation?
so i have rendered a scene and i want to add a color to 50% of the screen like this:

This is how i can do it in the VSE.
But is this also possible via compositor?
Sorry, my compositor knowledge is pretty limited....

You can use box mask for this and add color using color mix:

i knew it must work somehow...thanks!!!


text:
scale up my rigged character with animation
Beginner rigging question:
So i downloaded my character + animation from mixamo.
Now i want to scale it.
I found some answers here which said:

scale the rig, apply scale.
apply scale of meshes.
delete scale keyframes.

I did that (hopefully it was right) in this way:

scaled, apply scale
select the meshes, apply scale
open dopesheet, filter for scale, selected all keyframes, deleted them

But still...my animation is going weird after that. And my location moved too...so i obviously trapped into a rookie mistake... :(
my result:

All Mixamo animations (and many MoCap animations too) are completely FK, so they rely on bones rotations only, except hip bone, which is a master bone, carrying location infos also.
So you can delete all loc and scale keyframes except hip locations: what you're missing is that loc values get wrong when the scale changes: to solve, if the rig was scaled 0.01, you'll have to scale hip loc values by 0.01 too.
To do so, in the graph editor set the 2D cursor at frame 1, value 0; set the pivot point to be the 2D cursor, select all hips location keyframes and press S, Y, 0.01, Enter.


text:
principled volume does not accept my black color
so i have this little car scene here:

and just to prove that my volume shader "works" i rendered it out in blue.
Here is my result with black (nothing else than color changed):

Now, if i change the blue to black, it won't render in black, so looks like i have a basic beginner problem here and i don't understand the volume shader. What am i doing wrong?

What have you tried so far? When I'm looking at both images, the smoke seems to be very thin if it's still very transparent at a density of 2. Is the black color still invisible if you set it to 50? 100?

you are right, with higher density the black color appears but then my smoke looks really bad :(

Well, black doesn't reflect as much light as white, so the problem is the black seems to disappear inbetween the bright smoke. What you would need is thick black smoke and thin white smoke combined. So maybe you can get a better example when (instead of using a general density setting of 2) you use inverted black and white values as multiplier. But without the exact same smoke simulation I can hardly give you any advice how to achieve the best result.

@GordonBrinkmann: but thanks for your suggestion, i got an idea: i try to increase density just for black parts

Just my thought exactly ;)

i just got the idea by your comment ;)

if you want, write an answer, i will accept it and thanks for that idea!!!

Black doesn't reflect as much light as white, so the problem is the black seems to disappear inbetween the bright smoke, especially when the smoke isn't very thick and not absorbing so much light.
To try to fix this or at least get a workaround, you would need thick black smoke and thin white smoke combined. To achieve this - instead of using a general density setting of 2 - you use inverted black and white values as multiplier. And since the Color Ramp mainly outputs values between 0 and 1, you might want to add a Math > Multiply node afterwards to further increase the density.


text:
Blender to Aftereffects
On After Effect i have my png sequence (Blender Cube) and i'd want to mix on my video.
How can I do that?  I can see either only the video or only the cube.
The cube is png but i see the background black https://drive.google.com/open?id=1e8bOYkshku9GpN6cLOXVxEcgxEcILY2T

RENDER tab property> FILM tab, mark "make transparent".


text:
Sound won't play from Python script
I get the error AUD_FileFactory: File couldn't be read. Other files from same path will work. Logic Brick works on the same file.
Using Blender 2.79 on Windows 7. Any ideas ?

The sample rate is 96K and file was created with Audacity. I have tried "WAV" and "MP3". Other 96K mp3 and wav files will play with a python script and windows media player. And the problem file will play when using logic bricks. I would think if the logic bricks will play the file, it isn't corrupt.

Without further information on the audio file it is hard to help. Since the error seems to originate from the file maybe just opening it in any audio manipulation software like audacity and exporting it in a known file type like wav appears to be the best option. Also, you will know whether your file is damaged if other software can't handle it either.

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


text:
Non-Manifold after boolean modifier (difference).... Why?
I've made a simply (big) knob for potentiometer. After applying boolean modifier (difference) for create a starred hole (starting from a starred cilynder), the object come with "Non-Manifold"... Why? Anyone can help me? Thamks in advice.

It looks like the cut has its normals inside out. In edit mode select everything with A. Then recalculate the normals using Shift+N. If that doesn't work make sure that your cutting object is manifold before cutting.

Thanks... it work great! I'm only curious to how occour this...

there are many ways that this can happen, most of the time blender has to make assumptions on how you want your normals positioned sometimes it guesses wrong, sometimes the user accidentally assumes the normal is in one direction or the other. A telltale sign that something is wrong is the coloring notice how the cut in your photo appears darker than the rest of the faces, that is a signal that the shading is being calculated differently than the other faces. it's usually because the normals that are used in the calculation are facing the wrong way.


text:
How to import a class from other script
Im trying to import the class named "MyOperator", which is in the script "Operator.py", into the script "init.py" but the console shows me: ImportError: cannot import name 'Operator' from 'main' (_init_.py) Note: Operator.py and init.py are in the same location. Im doubting too about register the class this way: bpy.utils.register_class(Operator.MyOperator) or this way Operator.MyOperator.register()I have read a lot in different posts and i can't fix this problem.. The main script is:
import bpy
from . import Operator

class LayoutDemoPanel(bpy.types.Panel):
    """Creates a Panel in the scene context of the properties editor"""
    bl_label = "Layout Demo"
    bl_idname = "SCENE_PT_layout"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = "scene"

    def draw(self, context):
        layout = self.layout

        scene = context.scene

        # Create a simple row.
        layout.label(text=" Simple Row:")

        row = layout.row()
        row.prop(scene, "frame_start")
        row.prop(scene, "frame_end")

        row = layout.row()
        row.operator('my.operator',text="Operator", icon='MOD_MESHDEFORM')

def register():
    bpy.utils.register_class(LayoutDemoPanel)
    bpy.utils.register_class(Operator.MyOperator)

def unregister():
    bpy.utils.unregister_class(LayoutDemoPanel)
    bpy.utils.unregister_class(Operator.MyOperator)

if __name__ == "main":
    register()

Operator.py
import bpy
class MyOperator(bpy.types.Operator):
    bl_idname= "my.operator"
    bl_label = "Mi Operador"

    def execute(self,context):
        bpy.ops.object.select_all(action='SELECT')
        return {'FINISHED'}

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

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

Related https://blender.stackexchange.com/a/183817/15543

Hello, i've read that post and other similar and I can't fix the problem, the way of that post is avaiable to do it in the text editor? Or only works if I install the Addon? Can you help me, please? Thanks u

Looks like you are  calling register method from the main thread, ie when __name__ ==  "__main__"    Install as an addon and enable it, in which case dot  imports have a  module path.  In the link posted it mentions this.  If your add is in a folder named "foo_bar" can from foo_bar import Operator

Thanks u so much, I was trying to do the import in the Text Editor of Blender. Installing the scripts as an Addon I dont have more problems with the import. Thanks you sou much again, I had a headhache with this.


text:
Particle System in Pose Mode not working
I have one sphere with a one Particle System, I'm trying to rig it. I Select The mesh, select the bone, hit Ctrl + P And Use Set Parent with Object(Keep Transform). When I go to Pose Mode and move the Bone, only the sphere moves with it, and the particle system asociated with this sphere stay in the same position. I need the particle system follow the sphere.

I don't know why the particle system dont follow the sphere, which have the particle system.

The armature modifier needs to be higher on the modifier stack than the particle system.
Like this:

Not this:

You can use the arrows next to the X to move the modifiers around.

Ah okey, I didn't know it!! Another thing that I'm in problems is in the exporting the whole character. In allembic (.abc) The armature doesnt save, and the materials neither. And in collada (.dae) the particle system doesn't saves. Do you know what is the problem? The problem is about the type of the exportation? Or the data in blender?

I'm not experienced with how exporting in blender works to .abc and .dae so I'm not sure.


text:
Mirror and Offset UV Islands procedurally with Geometry Nodes
I am trying to mirror and then offset each island of my uv's. The UV creation and placement is by hand, but I would like to procedurally place their mirrored versions like so:

My problem is that I'm not sure how to get just the mirrored uv information, and then offset them consistently on a per island basis.
Here's my setup:

Is there a solution for this?

How do you know the mirrored half is not going to be outside 0>1? Do you want to center all the islands, too?

I hadn't thought of centering them, but that might work.
In my use case, all coordinates would be entirely outside of the 0>1 uv space. My hope was to mirror one side of a uv shell, and then automatically apply the mirrored half.
Maybe offsetting the UV after I mirror them would work, and having the direction they offset be based off a vertex group assignment?

I've had a preliminary look at this, and it's really hard to answer generally, IMO. There are so many undefined possible edge-cases. eg. What if a UV island doesn't have a geometry-boundary on the mirror-plane? or: What if a seam is on the mirror-plane, but not straight?  etc.  I wonder if you can constrain the problem in a way that suits your purposes?

Constraining the problem really helped. I figured out the process of doing this in Geometry Nodes, which involved first manually centering the UV's, and then mirroring them with geometry Nodes. Then I could use a manual material assignment and have Geometry Nodes offset to the left or right based on that assignment.
That worked really well, but then when it came to exporting to a game engine or another modeling program, I found that once the Geometry Node modifier is applied, it stores the UVMap information as an Attribute instead of as a UVMap. I could manually Convert Attribute in the Object Data properties, but that would take way to much time, so I took that approach and figured out a way of getting the same result with modifiers and vertex groups.
If anyone is interested in that solution it can be found here:
https://youtu.be/0NThmkqwa0M
And if anyone wants my Geometry Nodes setup, which I got similar end results (sans being unable to use it in other programs easily) then I can post that here too.
Thanks Robin, those questions really helped guide me to a solution down both paths!

Hi, I didn't downvote, but I suspect you got downvoted because you relied heavily on outside sources (your youtube video-- at least, I assume it's yours), you talked about problems with details unmentioned in the problem (GN nodes -> export to game engine), and because you didn't provide the full solution ("I can post that.")  It's probably too late, but to avoid downvotes, edit the problem to include relevant details like that, and detail your solution on SE rather than elsewhere.  Although I understand it may not be worth the trouble; after all, a downvote is really nothing.


text:
2.8 Grease Pencil Depth Order
I'd like to draw over geometry and use it as a reference for sculpting, but I'm having a problem with the depth ordering of the Grease pencil.
When it's set to Front, I see all of the line drawing, regardless of depth from the camera or objects in the way.
Setting it to 3d space results in the farthest lines from the camera subtracting from the closest lines.
Is there an option to get it look like the gif below in Depth Sorted? Where grease pencil lines are properly occluded by geometry? Or is that just something that's still a work in progress?
Thank you!

One workaround I've found is converting the Grease Pencil layer into a curve, and playing with the transparency and color of that.
It gives me the functionality I need as far as the visual presentation, but it does mean I can't edit the linework without going through the whole drawing/conversion process over again.


text:
Trying to parent a part of an object's mesh to an armature bone after I parented the mesh to armature
When I went to move the neck of a unicorn model I made in blender and parented to an armature, after adding and removing bones and adding bones  following some tutorials on bendy bones to make the unicorn's neck flexible. This happened:
Do I need to start the armature over completely?
Or is there a way to attach the neck's vertices to the neck part of the armature " the bone that is bendy for the neck. "  I can't find any option in blender that allows you to add a vertex group created after the armature is parented to a mesh, to the bone in question. Any help would be great thanks!

Please use print screen to take screenshots, not a camera.

I guess you need to make some corrections in Weight Paint mode, please share your file: https://blend-exchange.giantcowfilms.com/

That is kind of hard to do from my phone my PC has no internet connection so please forgive my lack of screenshot and use of phone camera. As for sending the file, I can't because I do not want the model to be stolen.

Overall I feel like this whole thing has been wholely unhelpful. I'll just redo the armature since this is the kind of response I get. Even if I wasted a few hours on the current one.


text:
Rigging in rigify for custom rig
I got a question. How do I create custom rigs in rigify made from an armature that I didn't rig to a mesh yet but I created the armature? I believe I would be able to do this because I read somewhere that you can add samples or even generate a rigify rig from a rig you built yourself from bones. But I have been unable to find a good tutorial on how to do this. Any help would be appreciated thanks.
The reason I am asking this is because I get the impression that rigify allows you to make non humanoid rigs and rigs with unusual anatomy.

Is it answered here: How to use the rigify building blocks for non human rigs?

That answer was kind of dated if it was the one I think it was.

It isn't answered clearly on that particular answer, for one the answer is really dated.... Like from four maybe five years ago, not current or particularly up to date. Second, the answer doesn't really tell you how to make your own custom rigify samples clearly, nor does it say anything about how to use a regular rig you built yourself to generate a rigify rig. My question remains mostly unanswered at this time. If anyone has a better answer please let me know.

The rigify addon functions still the same, even after 3 years. But I updated the info that animal parts are now available and included a link to the manual to an archive, because it is probably being moved atm and not available elsewhere. Hope it helps you now better.

Pls could you provide a link to this? I can't find it when I am trying to find what you updated ...

There is a link in my first comment to that answer, is it not clickable? Weird, maybe a browser issue.. this is the full address: https://blender.stackexchange.com/questions/44121/how-to-use-the-rigify-building-blocks-for-non-human-rigs

I read the manual, but it really doesn't explain anything like making a armature rig you built from a single bone and then generating a rigify rig from that armature rig. I can't find anything that is really understandable that tells me how to do it.

I'm guessing that isn't within the scope of it's functionality?

You can absolutely customize your Rigify Meta Rig which would allow you to rig (almost) any character. The "secret" is in understand the Building Blocks or "rig types" that Rigify provides.
I made a tutorial series on exactly that. Here is the series page
https://cgdive.com/rigify
Or the youtube playlist
https://www.youtube.com/playlist?list=PLdcL5aF8ZcJv68SSdwxip33M7snakl6Dx
I hope this is a reasonable "self-promotion". There is very little info on this topic. I learned the basics from this video by Ivan Cappiello (one of past maintainers of Rigify)
https://www.youtube.com/watch?v=txJ-2zUQSTg
And of course, there is the Rigify manual which can be very useful. However it is has been lagging behind the actual development of the addon.
The 2.8 manual actually does not include images as of this writing.
https://docs.blender.org/manual/en/dev/addons/rigging/rigify/index.html?highlight=rigify
So it may be better to look at the old version of the manual
https://archive.blender.org/wiki/index.php/Extensions:2.6/Py/Scripts/Rigging/Rigify/#Advanced_Usage


text:
How do you apply a glossy node to a specific image texture when using alpha and RGB mix nodes?
I bet it's an easy fix but considering I'm a newbie take it easy will ya, anyway here's my node setup.

the highlighted nodes contain the transparent image texture I'm attempting to make glossy.

As you're dealing with glossy, you're dealing with shaders, not color anymore, so you'll have to use the "mix shader" node instead of the "color mix" node. It also can be controlled by the alpha output. In my example only the second texture has glossy.


text:
How do you select the inside vertices of an object faster?
I've been seeing some tutorials and they all make two mouse clicks and somehow manage to get a clean selection of the inside vertices with no use of Alt or the B key which is what I usually have to do...asking for a friend.

In your case you could simply select the bottom central vertex then ctrl+ to automatically select more. I guess it's the trick you're talking about. But B or lasso select tools would also quickly do the job.

You could select the element in the center(face or vertex) and hit Ctrl++ multiple times to grow selection:

You can also Alt+click to select some loop and then use "Select Loop Inner-Region" function that you can find in the search menu(Space/F3(2.8)) or in the Select menu in the 3D View header:

You can use the Select Linked function in Blender. This can be done using Ctrl + L or Cmd +  on Mac


text:
How do you make the inside color of a cup different from the outside?
I want to change the color of the interior cup but I can't seem to do it without the image texture being deleted when I attempt to transition from image texture to color. Even after the material gets duplicated.

You could go to edit mode and select all the faces inside the cup that you want in a different color. Change to vertex mode and make the selected vertices a vertex group. Then add a new material for the cup and assign this material to the vertex group

A method that will let you alter add and subtract any vertices in the Object is using the "Backfacing" socket to drive the Factor of either a Mix RBG or Mix Shader Node.
The Input > Geometry node has Backfacing as an option near the bottom. Your screenshot shows Cycles and that's the only time I've used it to change colors or shaders on an object.
To be perfectly clear, a cup with no actual depth, that's one polygon thick at the walls, would have two sides. The outside or, presumably front-facing polygons, and the inside or, back facing polygons.
Setting the material to blue, for example, would affect the inside and outside evenly. Using Mix RBG and selecting Orange as the second color would benefit from the Factor Socket being filled with something. When that something is 1.0 at value, the color will be orange; at 0.0, blue.
Some inputs like the Noise Texture allow various factors 0.75, 0.13, etc. Backfacing either IS or IS NOT true. So, where the object's geometry is YES back facing, the Mix Factor will be valued at 1.0 and trigger the lower option. Where Backfacing is not true, Blender will return 0.0. So don't get too confused about what the Socket means and which output to expect!
This also works on closed Objects like cylinders. Flipping Normals will also direct Blender to consider the back face differently but other aspects of materials or physics might not perform correctly; so don't cheat by flipping the Normals!


text:
How to make a plane responsive to light?
I need the plane color to be white and the lambs to only expose the plane beneath it. However the plane just lights up on it's own even when using really dark colors. How do I fix this? I've checked the world lighting. Emissions, and none of these are even on. I'm on cycles engine.

I'm not 100% sure what you're going for, but I made this scene with just text, a plane, and a single spotlight (Material added to the text - everything else default). This is in cycles engine, and I left my world properties panel open so you can see the settings. If you cannot reproduce, you may be suffering from some kind of bug, but I think more likely you have too strong a world background (cycles picks up even faint World Lighting), or hidden lights. Look at the example and let me know what I'm missing:


text:
How to remove or minimise compression banding in Blender video export using FFmpeg?
When exporting video with very subtle color blending like lights in fog a compressed video will create banding where there was none before, even with the best in-Blender settings e.g. "perceptually lossless" etc.
So far my best solution is to export all frames as .BMP image sequence. (exported PNG images have banding).
By using FFmpeg free software one can apply the following line:
ffmpeg -i "input%04d.bmp"  -c:v libx264 -pix_fmt yuv420p -tune film  -preset slow -crf 1 output.mp4

This will significantly reduce banding to almost unnoticeable or sometimes imperceptible.
I wonder if you have discovered a better method or better settings for FFmpeg? My solution above is an optimum between size and quality, but I am not an expert on FFmpeg.

Try WEBM/VP9 as the codec, I think it's basically h265 - so ought to be better then h264 for rendering gradients (you'd hope: it's somewhat newer!), it's probably still only 8bits deep though. I must admit I only really use FFMPEG or any animation type export from Blender for tests/previz though, if you want it really pretty go for anything 10bits or better deep, as in not 8bit PNGs or such like, and obviously low/no compression, then compile the animation in FFMPEG / Handbrake / Blackmagic Fusion or whatever.


text:
Simplifying geometry
first of all, let me tell you I'm a total novice in 3d modelling, my experience is with Sketchup only.
Recently, I came in need of a particular model, and I got it in a STL format.
Sketchup imported it just fine, however, the mesh is so loaded with unnecessary details, it makes the application just freeze.
I was told Blender can solve this problem, so I came here to ask you how can I make it a clean mesh, without losing detail but making it lighter so the software can run (and no, it's not a hardware problem, I'm using a GTX 1070 with 16gb ram and up to date processor)
This is what I'm talking about:
https://i.sstatic.net/8nGuf.jpg
Sketchup can't handle that many faces.
So, how do I fix it using Blender?

There are a couple of things to reduce the meshes.
You can find the most part in the Mesh > Cleanup menu.
Remember you have to enter the Edit mode.
Also a Mesh > Faces > Tris to Quads helps to reduce the edges.
See the image below:

Also try the Decimate Modifier and lower the Ratio slider.


text:
Render Obj is all black
I have an issue similar to this problem  when I want to render an 3D .obj, I tried the methods proposed and get the same result as following
Firstly, I deleted the origin cube and import my .obj mesh car, then I shift the view to the local and use "Ctrl+Alt+ Numpad0" to align the camera to my viewport. Finally I click the "Render" button and come to this situation.
And my .blend file is also attached here.
Waiting for your help~

Try to adjust the lamp.

Thanks, following your advice, I change the lamp type from point to the Hemi, and enhance the light Eneregy to 2.0, and finally get a perfect result.


text:
Not able to find 'Area Plane' Brush mapping in Blender Texture painting Brush menu?
Not able to find 'Area Plane' Brush mapping in Blender Texture painting Brush menu. This is available for Sculpt Mode why not in Texture paint mode?

View Plane isn't what you want?

"The Flatten brush finds an ‘area plane’ located by default at the average height above/below the vertices within the brush area. The vertices are then pulled towards this plane. The inverse of the Flatten brush is the Contrast brush which pushes vertices up or down away from the brush plane."   This means that Area Plane is a calculation with geometry, and not applicable to Texture Paint. If you want to affect the paint through geometry, then see the use of Cavity masking. https://youtu.be/6Ac6LqBW9H0?t=103

According to Blender Manual, this mapping should align brush to surface normal. but it doesn't. https://docs.blender.org/manual/en/latest/sculpt_paint/texture_tex_mask.html

It would be nice if they added the brush area plane feature from sculpt mode to the paint mode.
Sculptris has a feature in its paint mode similar to the area plane feature in blender sculpting where the brush flows along the contours of the surface as if projected along the normal rather than from the camera view.
The brush projected along the normal view would prevent the stretching caused by the brush being projected from the camera view.
Another suggestion if its not already a part of Blender would be to add a bit of control over the falloff for the texture brush so that the texture does not paint past a curved face or edge.


text:
Material/Texture Problem
I was rigging a character from Mario Kart and the model I got already contained materials for the meshes, I checked to see if the materials worked, and it did! so after following a tutorial on how to rig a model, I was fixing a weight paint problem and did the best I could to fix it, when I finally did and checked the material/texture, her whole body was brown instead of the material/texture it uses, I really don't want to start ALL over again with the weight paint process so hopefully this is fixable, thank you.

can you please upload your .blend here? http://blend-exchange.giantcowfilms.com and attach it to the post?

Possible duplicate of How to set an uv map, from an multiple uv, as primary one?

@ScottMilner that helped, but now the face turns gray

@Chris Yes. Blender has the limitation of only displaying a single UV mapping at a time in the viewport. It will still render fine.

@ScottMilner ok but before it displayed both UVs, now it renders with whichever has the camera clicked on

@Chris https://blender.stackexchange.com/questions/18346/texture-mapping-with-multiple-uv-maps


text:
Textures Not Showing in Viewport (Blender 2.8)
I'm working in the new 2.8 with someone else's file (made in a previous version of Blender), and I can't get the textures showing in the viewport. I've relinked all of them to the correct location on my computer and Blender can seem to find them, but just won't display them in the viewport. I've made sure I'm in LookDev mode, and also added a lamp, but still nothing.
In 2.79, it was always just a matter of finding missing files and that's it...
Can anyone see what I'm doing wrong here?
Thanks!

Maybe your version of 2.8 has a bug but I don't know why you'd go to lookdev mode to see your texture: just stay in solid mode and set your viewport to textured and tell us if you still have this problem

Not sure what you mean... Version 2.8 doesn't have a textured viewport option, as far as I know. According to other threads here, it's been replaced by Lookdev mode.

at the bottom right of your screen shot, at the left of "Shading", you have 4 buttons which correspond (from left to right) to your "Wireframe", "Solid", "Textured" and "Shaded" views. to see your textures you usually just have to select "Solid" in the pie menu appearing when you press "Z" and click on the "Textured" button. no use to be in LookDev mode

What you're referring to as "Textured" seems to have been replaced by the term "Lookdev". As you can see in the two screenshots here, the buttons you mentioned both in the bottom row and in the pie menu are called "Lookdev" in v2.8 (see tooltip).
https://imgur.com/a/LVbqn6u
https://imgur.com/a/91DUGEj
In any case, pressing them to activate this mode, however you call it, doesn't make the textures show up.

You've got the point light selected in the screenshot. If you select the body mesh is the texture updated or even applied there? You may have to recreate the material as well depending in the render engine used.

A bit off-topic, but there is kinda Textured mode in 2.8 however it is not mode by itself and doesn't have any shortcut; it is in Shading > Color > Texture and it does work without switching to Lookdev, suitable to quickly check UV layout and texture on the mesh

Blender 2.8 uses an entirely different materials system from previous versions. As a consequence of this (and perhaps also as a result of some missing backwards compatibility features in Blender 2.8), image-based materials created in older versions of blender get replaced with plain, solid-color materials with no textures when opened in Blender 2.8.
To fix this, you will need to manually re-assign textures to their appropriate materials in the project. Select the model you want to fix, then in the properties editor go to the materials tab, select a material to fix, and click "Use Nodes". Next, click the small button to the right of the "Base Color", and click "Image Texture". Finally, click the image dropdown below the base color, and select the correct texture for the material you have selected. Depending on how well named the materials and textures are, you may have to use a bit of trial and error to figure out which texture goes where. Now repeat this process for every material in the project.
Yes, this could be extremely tedious depending on the size of your project, but until Blender introduces a built-in way to convert old models to the new materials system this is what we're stuck with, apparently.
For more information on this issue, see Opening old .blend files (missing images) on KatsBits.

Brilliant.  Solved my problem. Thank you very much!

This should be marked as the answer.

TO ALL NEWBIES (like me): remember to press Z and choose look dev!

The real problem is Blender gurus didn't default the view to show textures in edit mode if that's where you edit the textures. If you think you are setup correctly simply Press Z then choose Look Dev. Your texture should show up. You can also switch to texture paint and texture will show up but it's kind of silly you cannot use the UV editor which would actually make more sense since it is texture paint mode. Poor thought in this aspect.. If I am in the UV editor Blender should default to showing Look Dev not stay in solid rendered or wire framed. If I am in Texture Paint mode it should allow changes in UV mode because that is part of texture painting not modeling.

Yes, thank you! Even though I rendering of textures was off, I could not figure out how to turn them on for anything. After turning it on as you suggested I went through each button in the 3D viewport in turn and finally found that that the globe-like buttons at the top right can also be used to set the viewport rendering mode (which is called "viewport shading" so that no one will guess what it does).

The texture might be tiled.
To change:
1. Go to PROPERTIES PANEL --> "Active Tool & Workspace Settings" (the screwdriver & wrench)

2. Find the TEXTURE TAB --> Change MAPPING from "TILED" to "STENCIL"

After this change, my texture was visible in viewport:

I ran into a similar problem doing a Blender 2.8 sword tutorial on youtube. Answer credit goes to the comment section of that tutorial:


text:
Mesh object select shortcuts
I was wondering how in Blender 2.8 do you activate the shortcuts for the mesh objects in edit mode. That being 1 for vertex 2 for edge and 3 for face.
https://www.youtube.com/watch?v=W99lFlWrbCk&t=19s
7:25
Thanks so much
Umar

It should be enabled by default but this should work:https://blender.stackexchange.com/questions/106224/custom-shortcuts-replacing-ctrltab


text:
How do I merge the body and the legs?
So this is my first time modeling a body and I've made the torso and the legs in different objects so I wouldn't mess it up, now I don't know how to merge/connect them to make it a single object and the "Subsurf" modifier doesn't appear on the modifiers tab, I also don't know how parent vertexs work nor how to subordinate other vertexs.
Here's a picture of the objects I'm talking about:

Select the objects, press Ctrl J. The objects are now one.

I select both of them on the "Scene collection" and press Ctrl + J but it doesn't do anything

Do these actions in the 3d viewport

Which one is that?

I would try this:
Select your leg on Object mode, change to Edit mode
press "A" to select the whole leg
copy with ctrl+c
unselect clicking everywhere else
turn into object mode again
hide the leg you've just selected before with "H" and select the torso on object mode
change to edit mode and PASTE THE LEG (CTRL+V)
If I'm right, now you have a leg into the vertices group of the torso and now you can link them!

I copied the legs with ctrl + C but when I tried to paste it on the "Torso" tab with ctrl + V, multiple tabs opened like: "Extrude Vertices", "Bevel Vertices", "New edge/face from vertices"... etc. The torso and the legs are still two different things(?), and sometimes the legs appear to be selected even tho I only have the torso selected and I think that's pretty weird

I think you may want to go through Blenderguru's Blender for Beginner's  tutorial before jumping into character modelling


text:
"Freestyle" lines not complete, missing or inexplicable
See title. I marked the inexplicable lines red and the missing ones green, how I would like it to be. I use cycles, does that matter anyway? What settings do I have to use or is there a good comprehensible introduction?
The ornament is one (applied boolean unison) object.


text:
Unexpected behaviour of bevel
I made sure there are no redundant vertices. It is one object. I expect it to bevel (Ctrl + B) like in the first picture, but what it does is on the second. Did the bevel tool change in 2.9x?

Check to make you're normals are all facing the right way (select all in edit mode > Mesh > Normals > Recalculate Outside)

This worked. Many thanks!


text:
Changing scale without changing dimensions
I am facing some troubles with the size of an end cap of the Array Modifier. I want to change solely the size of the cap to make it longer. It appears that I can influence the size of the end cap solely by scaling the object on which the Array Modifier acts. However, I don't want to change the size of that object anymore, thus my question: How can I solely change the scale of an object without changing its size or dimensions.
On the internet I just found the question for the other way around by applying the scale.

You can simply scale the origin of the object.

Check Tool > Transforms > Only Origins
Scale your object (it won't visually change dimensions)
Done.

Is there a way to make the Scale input boxes in the Tools > Transform menu also scale only origins? Currently it seems this setting only affects scaling in the 3D viewport.

Hi :). No idea, but perhaps if you share your problem, somebody can offer an alternative :).

Did 4.0 affect the menu? The option isnt there anymore

It works for the simple cube, but I figured out how to do it with an armature that is connected to a mesh because sometimes things like this happen when you just scale and then press Ctrl+A:

I accidentally found out that it works if you scale it and use Scale to Deltas instead of Ctrl+A:

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


text:
How do I attach an object to specific trackers?
I have been sitting and trying to solve these problems for ~6 hours, but to no avail.

I tracked my image sequence with the default Detect Features button and added my own trackers, but object in my scene reacts only to Detect Features trackers.
In addition, on some frames, it "leaps" to some positions for no reason.

Why is this happening?

The first thing is probably because you didn’t select your own trackers when you tracked. The second is probably solving errors because it didn’t have enough trackers to work with. However, if a tracker really is following the exact same point on an object, it will not generate errors. More trackers just creates more precision. Are you trying to track an object that bends during the video clip? Tracking expects it to be one solid object and the same points being tracked for each tracker.

@ZargulTheWizard I think I tracked manual trackers screenshot, and yes, the object has to rotate

I said bend, not rotate.


text:
How to apply procedural material on a mesh?
I tried to use a texture coordinate, but it didn't help. UVs don't work. Any suggestions?

Hello, you say that UV doesn't work but it should, maybe you need to unwrap and adjust the UVs in the UV Editor?

I adjust it in the edit mode by selecting all -> pressing U -> smart uv project. Is that correct way?

did you put a Texture Coordinate (UV output socket) > Mapping > Brick Texture (Vector socket)? Smart UV Project should work for your object.

Yes, I used this order of nodes: Texture coordinate "generated" to  Mapping "vector" to Brick Texture "vector"

please share your file: https://pasteall.org/blend/

file - Here it is

Bro, the uv map is messed up. UV wrap it properly and trey to match it properly

As Maulik says, your UV is messed up, so the texture won't be correctly projected if you use the UV output socket:

So re-unwrap your cylinder, you can switch to front view and choose Unwrap > Cylinder Projection for example. You'll need to unwrap the top face and make it match as much as possible I guess:

Use the Texture Coordinate "UV" output socket:

it still didn't help( When I press any button that changes the UV map, nothing happens

in the 3D view, select your cylinder, switch to Edit mode, choose front view, press U to unwrap > Cylinder Projection

That's what I do! Exactly these steps. And when I get proper UV map, I try to modify it in the UV map editor, and nothing happens. I even try to move the whole map link 1 link 2

what do you mean by "nothing happens"? You show an image in your screenshot but in the file you share it was a Brick Texture node

Sorry for the image, but when I modify UV it doesn't matter what image is shown in the UV Editing, right? If yes, I select everything in the Edit mode and UV Editing and try to move it in the UV Editing

sure but if you've changed some settings I'm unable to see it, please share your last file so that I can test it

I haven't made any changes, but here's the video of my actions - video

yes but what about the shader editor? are you using the Texture Coordinate UV output?

Yes

You need to use the Texture Coordinate "UV" output, see my edit

Let us continue this discussion in chat.


text:
How to extrude faces in the form of triangles depending on their position?
I want to extrude smooth convex triangles like in this photo -

But I don't want to do it manually, besides they are not the same.
How can I do that?

hello, what do you mean by "manually"? without addon?

Not only, I can do that just "Poking" faces and drag every centered vertex, but how to apply that to many faces at once with "stretched" effect?

https://blender.stackexchange.com/questions/26794 https://blender.stackexchange.com/questions/77027

Also useful examples

Create a UV Sphere, select all and press CtrlE > Un-Subdivide, in the Operator box choose Iterations > 1:

Cut the top:

Select all and press i twice to inset individual faces:

Scale up:

Transform a bit, give it a Bevel modifier:

No way! That's exactly what I wanted. Thank you!

I tested Poke Face, I don't think it is useful here, but if you ever need to select similar vertices/faces/edges, press Ctrl G (Select Similar) and check the options

Ok, thanks again


text:
How can I create a quantum fluctuation simulation?
I'm trying to replicate this real quantum fluctuations observation using Blender.

So far, I have used Principled Volume and Voronoi texture to create clouds. However, I can't get my head around how to animate them to look like actual random fluctuations.
If, say, I use the Mapping node, then it would just shift, rotate or scale individual clouds, whereas they have to pop in and out constantly without an obvious pattern.
Their edges are also blurry, and I couldn't achieve a sharp look with the ColorRamp.

What about setting to 4D in your textures, and play with the additionnal input ?

I'll need to render it properly, but it seems it does the trick; thanks!
What about making the clouds sharper?

Probably set the density to 0 ?

Nope, that one is responsible for the fade of the clouds. The clouds themselves are connected to the emission and are not dependent on density

The density fills the space in between with the dark blue fog. But your exemple isnt volumetrics so I dont understand your goal exactly.

(source : http://www.physics.adelaide.edu.au/theory/staff/leinweber/VisualQCD/ImprovedOperators/index.html . Context : this is a gif showing the smeared action density as a function of monte-carlo-time (not real time))

(sorry, it's probably in euclidean time, not in MCMC time)

Volume to mesh (Geometry nodes)
Simple setup
Your example shows a geometry with solid faces. Here is a simple way of creating the mesh in Geometry nodes.

Basically :

Spawn a Volume Cube with a custom density
Convert the Volume to a Mesh
Store the custom density as an attribute, to be accessed from the shading editor.

The downside is that a good quality mesh is expensive to compute. A workaround is to setup 2 different resolutions, one for viewport and one for render. Taking 1 second to compute the mesh at render is OK, but in the viewport it should be quick (real-time).
Setup with workaround
Here is the full setup with two resolutions :

Notes and blend file

I didn't spend much time on the texture controlling the density. You probably can keep your existing nodes.
With a low resolution, the mesh is quite low-poly and so the material too. But it shouldn't be a problem while working with it, it will only be blurrier.
The pink input of W in the noise texture node is a Driver.

Notes:

Animate Musgrave (Voronoi or what ever) Texture > 4D - W parametr
Render Properties > Volumes > Step Rate Viewport/Render 0.2


text:
How to fix brick textures proportions on my objects?
I have been following this tutorial to make tiles; however, a problem I have it making it be able to look nice and be able to place on all sides.
From the node editor, I have tried setting it to both UV and Object for the Texture Coordinator into the Mapping. The Object setting is something I would like to use as it looks the nicest where when I assign it to two objects and put them side by side, it looks very nice and well connected but it only seems to pick and choose what faces to pick, usually on the Z-axis it seems. However, with UV, it looks messed up, even trying to mess with the UV doesn't help.
Here is the example using the UV Coordinator. As you can see, my tunnel that I made doesn't connect well with other objects.

Here is what it looks like when I use the Object coordinator. It looks well connected and just looks nicer. This is the result I want, well...almost. It doesn't seem to like to affect the sides very well. Either stretching or non-existence.

Here is the entire node setup. Apologies for it being a bit blurry. I didn't exclude the mapping since it changes twice. If you want to see the entire node system. The video of the tutorial shows the node system in higher definition.

How can I fix it so it looks nice?

"However, with UV, it looks messed up, even trying to mess with the UV doesn't help." More details around this seems important. "Messing with the UV" should exactly help. What did you try in the UV editor?

Change your material to something simple like the color grid image texture. Then you can see distortions. Eliminating distortions can be tricky, basically you need to UV unwrap correctly. In your case however it's not local distortion, just disproportion of UV islands, I think. Once you solve local distortions / overall disproportions, there's still a matter of varying scale, which you can fix by selecting all objects, going to UV editor, selecting all geometry and then from menu UV "average island scale". Watchsome tutorials on UV unwrapping and modelling, because you have a lot of overlap.

@Phrogz I have tried unwrapping it, setting it to cube projection, cylinder projection, sphere projection, and Smart UV Project.

But you have not tried manually moving the UVs of faces or groups of faces to produce the result you want, in the UV Editor panel? I resisted learning manual UV editing for a long time, but it's not really that complicated. (I'm sure there are a billion tricks I don't know, so I'm often doing it the long way, but the core tweaks, overlaying vertices and edges on the image, are pretty simple.)

Its all in the marking of seams, UV unwrapping and a little UV editing.
But first, before UV unwrapping, the XY and Z rotations of the objects should be at 0°  and the XY and Z scales should be at 1.000. Your Tunnel object has a Z scale of 0.597. This would lead to the scaling issues when Unwrapping. To fix this, in Object mode select object, > open Object menu, > Apply, > All Transforms.

Transforms applied :

Mark seams and Unwrapping.
In Edit mode mark seams along edges so that when unwrapped the UV's are distorted as little as possible.
Do a test UV unwrap: Edit mode with tunnel selected > open the UV menu and choose the basic Unwrap option.
I'm guessing a lot of the UV's will be distorted so go back to the model and add more seams and unwrap again. :)
When you think you are getting somewhere change to Viewport Shading > Material Preview mode. Then change the material to your Checker texture and the output of the Texture Coordinate node to UV. Now you can see how the texture maps to the UV's. Don't worry about parts appearing to be differently scaled work on distortions of the checker texture. Note: Distortions are alleviated by adding more seams. For a model like this the UV islands should all be aligned to the X or Y axis in the UV space.
I have included a finished .blend file with all the seams marked and unwrapped etc. Just take a close look at where I have marked the seams.

Repeat above for Entrance object.
Note. for the front faces of the Tunnels arches it is a little more complicated. In front orthographic view select one of the arch's faces > UV menu > Project from View. To get the tiles aligned to the arch shape we next need to do a second UV unwrap of the arches this time using using the Follow active Quads method. Its not differcult to do: just need to square off one of the arches UV faces ... here is a short video that explains how to:
https://www.youtube.com/watch?v=hSMpNeV0vKM
When you have the arches Uv islands straightened out select the island in the UV editor and hit the P key. The vertices of the arches UV's will have turned red indicating that they are Pinned. This means that they will not be unwrapped again unless you Unpin them first. Unpin is Alt P.
Ok now both Tunnel and Entrance are UV unwrapped etc but the scale is not the same all over the models. To fix this we need to unwrap both objects together. In object mode, select the Tunnel object then Shift select the Entrance object (both objects now selected) Go into Edit mode and select All > UV menu > Unwrap. Both objects have been unwrapped together in the UV space and unwrapped to the same scale as far as possible. The pinned arches will be differently scaled so select those two islands and scale them up/down some until the checker scale looks approximately the same as on the rest of the model.

Finally change the Material of each object to your Poolroom_Tiles_2 material and Texture Coordinate node output to UV.
Play around with the X Y Scale values in the Mapping node to get the tile size that suits you best. If necessary, you can edit, move along XY axis, and rotate individual UV islands so that they better align to each other etc. Note: It does not matter if the UV islands stray outside of the UV space.

Marking seams and UV unwrapping etc just takes a bit of patience and of course the more you do the simpler it gets. For future projects have a look for tutorials on Live UV unwrapping in Blender.

Thanks a lot for the detailed explanation. Very detailed and helpful.


text:
transparency issue in blender render with shading?
Unsure how to fix this problem, just a generic fire in a fireplace, but the transparency isn't working correctly for some reason.
I'm in Blender Render. Not sure exactly what to search for to find the answer to this so I'm just asking.
Thanks, and I'm sorry if this is a repost of a previously asked question.

Possible duplicate of https://blender.stackexchange.com/questions/99864/distorted-plane-as-image

not a duplicate of either, the top link the transparency wasn't working on the imported image, the second one was done in cycles rendering. i figured it out though. I had to deselect traceable under material>options though neither link answered the question they did help me find the answer. thank you

when using a transparency in Blender Render ensure that in the material tab , under options that the traceable box is unchecked so as to not cast a shadow on the transparent portion of the texture.

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


text:
Can't bake a simple cup for sketch fab
I've been working in Blender for about 1.5 years now and I found a serious problem, that I cannot resolve myself.
The problem is Baking textures in Cycles Render mode (actually in every mode), which seems to bake a textures black and no shadows, colors, AO, nothing just black. Only normals and UVs bake shows something different and correct I guess.
I tried many techniques to make it work somehow but neither of them tell me the right thing. I tried this and this.
They somehow seem useful but it still doesn't bake right. If you need my graphics info and Blender version: AMD Radeon R9 200 series Blender 2.78 Intel core i5-3470 CPU
So these are the steps I always followed:

Open a new project, set up a simple cube and a sunlight
In edit mode unwrap that cube using Smart UV Project.
Add a new image 512x512 without Blank option enabled
Then I made a new material in nodes editor (image bellow) with an
Image texture node connected to the Diffuse BSDF node. I kept the
image texture node selected and began baking, by clicking the Bake
button.
It didn't work so I even tried recalculating normals, making sure
it's not duplicated (the object) and checking if there aren't 2
materials active. I tried making a new project too but the probled
doesn't seem to go away.

Thank you for helping!
Here is link to file
https://drive.google.com/open?id=1_DkQR3JFfO14KWdWCL6uKS4eLWrKH-fu

You shouldn't have the wood image texture selected, when you do that a circular dependency is created, since you are trying to read the wood texture for use in baking and write to it at the same time. In fact, Blender warns you about this in the title bar:

What you should do is create another empty texture and select it to bake the texture onto:


text:
Selecting a new material slot to selected vertices
I have a few vertices selected and would like to change the colour of those vertices with Python script. This means adding a new material slot.
I have tried this script, however it changes all the vertices and not the ones selected.
activeObject = bpy.context.active_object #Set active object to variable
mat = bpy.data.materials.new(name="MaterialName") #set new material to variable
activeObject.data.materials.append(mat) #add the material to the object
bpy.context.object.active_material.diffuse_color = (0.121583, 0.144091, 0.8, 1)

What's your question? Cycles, BI or Eevee? BTW: Alternatively have a look into vertex colors: https://blender.stackexchange.com/questions/909/how-can-i-set-and-get-the-vertex-color-property

Vertices don't have material data, the material is assigned to faces. bpy.context.object.data.polygons[0].material_index

I meant faces not vertices. I would normally select the object, go into edit mode, then add plus to add a new material, then add new, change the colour, then asign, then exit edit mode.

@MichaelTeiniker When posting programming or scripting answers properly formatting code is important for others to be able to help you. Whenever necessary use the builtin tools to properly format your posts.

One way to do this:
import bpy

mat = bpy.data.materials.new("PinkMaterial")
mat.diffuse_color=((0.8,0.2,0.8))
bpy.context.object.data.materials.append(mat)

for p in bpy.context.object.data.polygons:
    if p.select:
        p.material_index = len(bpy.context.object.material_slots)-1

This would add a pink material to the active object and then go through it's faces to see which ones are selected and then change their material index to the last one.
There might be more efficient ways to do this as well.


text:
some vertices won't snap when using knife tool
I try to cut through my face by just selecting vertices with knife tool, but it snaps only on one vertex so obviously i am doing some beginner mistake here.
What do i have to do that it snaps to all vertices?

blend file:

The vertices you're trying to snap to are not part of the face you're trying to cut through. You can't cut through nothing to join a vertex to another one.

of course not...that's why i want to cut through....

then the snapping makes just "a bit" sense...if i cannot snap to "all" vertices...or can i change that behaviour somehow?

umpf...that's disappointing. i just wanted to cut out that section which i cannot snap :(. ok, i ask another one how i cut that through....

my answer is not accurate enough, I need to formulate it correctly

Better to use a boolean modifier for that I'd have thought.

Yes duplicate the shape, extrude it, use it as boolean


text:
Intersection of multiple hard surface pieces
I tried to reproduce the amazing answer of Robin Betts here:
What is the best way to model the intersection of multiple hard-surface pieces?
Unfortunately i couldn't make it.
This is my frustrating result:

my settings:

what did i make wrong that i didn't look that amazing as Robin's answer? and why is my ring not closed?

I think that your problem is that you've created the oblique edges with some Fill (F) while you should have used Join (J). Fill will create an edge over the existing face while Join will cut the face in 2 halves, which is supposed to happen here for the topology you're looking for.
Here if you select the face you'll see you have a unique face, delete the oblique edge and join the 2 vertices and it should work:

it is a shame how little i know! :( THANK YOU!!!!

hey we are all improving every day with Blender  ;)

yes we DO!!! ;)


text:
why are my cylinders stretched if i use this geometry setup
i have this very simple geometry nodes setup:

result is:

my cylinders are stretched. I would have expected that the cylinder form is the same, but the just got bigger distances. Why is that?
blend file:

This is happening because you're doing the operation (in this case add on x-positions) after instancing the cylinder. So, you're modifying the x-position of each vertex of the instanced cylinder instead of the x-position of the points that you used for instancing.
Thus, you have to first modify the x-position points then use them for instancing of cylinders,


text:
shortcut to select all objects in collection in outliner does not work
I have set a shortcut to select objects in outliner like this:

If i select the collection and tap my shortcut key...nothing happens.
If i select the collection and tap the menu point with the assigned shortcut key - works.
Is it a bug? Does anybody know a workaround for this? Or am i doing this wrong?

This operation is context sensitive : It will only work if your mouse is hovering over an outliner editor.

@Chris I don't even have the option to assign shortcut for such operator https://imgur.com/UD95S6W How did you assign it? :) BTW is it a time-saver since you have to select Collection first?

It saves 2 clicks so….YES and because I use trackpad - my steering isn’t that exact

@vklidu: i right clicked in the outline on that menu entry ;)

@Gorgious: even than...it is not working :(

It is not working because Alt+A is already assigned to Toggle Selected

OMG.....thank you!! Cannot believe i didn't check that....♂


text:
Vertex Paint no longer adds color
I modeled my object just fine, then went into the Texture Paint tab, and, using Vertex Paint, I was able to paint my object looking kind of how I wanted. However, I did something which is now preventing me from adding any new color or changing any existing color. Whenever I try to paint, nothing happens. I have a color selected in the Color Palette, and I am using the Draw brush, with a blending mode of Mix, with a Strength of 1.000.
After playing around, I discovered that I can switch the blending mode to Vivid Light, Linear Light, or Pin Light, and it will draw on my object. However, regardless of what color I have selected, it will only draw black. If I start a new file, and go into Vertex Paint, I can color on the default cube just fine, but, when I reload my saved object, painting stops working again.
Any help would be appreciated. Thanks!

Check the brush type is "Draw" and the Blend is "Mix"

Thank you for the suggestion Jan. I am trying it with a brush type of Draw, and a blending mode is Mix, but it doesn't color the object.

can you please upload the file here and share it? https://pasteall.org/blend/

I gave up and switched to using a texture instead because that painting still works. But thank you so much for wanting to help!

All those options can be sometimes confusing, I recommend to read the manual, it is really well made and maybe you will find the answer there :) https://docs.blender.org/manual/en/latest/
Good luck (and patience) and happy Blending! :)


text:
BoxCutter and industry standard settings conflict
When using industry standard keys, alt+lmb rotates the view. This same keyboard combo completes the operation of a boxcutter Boolean operation. Basically, you are able to start and manipulate the projected shape as long as, and until you desire to rotate the view to get another vantage point on your model. This is a problem in that the tool is completely useless with this limitation. Any help would be appreciated.

You can edit the keymap to give boxcutter a different keyboard combo for completion.

How and where? I have looked through all of box cutters shortcuts and none of them are for combo for completion. Thanks for the help!

This is a limitation of using “Emulate 3-button Mouse.” If you have a mouse with a depressable scroll wheel (AKA a third button), use that instead of Alt-Lmb to rotate the view as it is really standard.

The industry standard keys do not have any options for emulate 3-button mouse like the default blender keys do. Also, it defaults to alt+lmb for orbiting/rotating the view, which is industry standard in Maya.. and I quite prefer it. My goal is to use the industry standard shortcuts profile and still be able to use boxcutter. Is there no way that I can change the alt+lmb apply function within boxcutter to something like ctrl+shft+lmb?

Okay, I thus have no idea what you mean by “Industry Standard” keys, but if the orbit thing collides, it collides. Yes, you should be able to change they keymapping for the box cutter.

Thanks for the help. Do you know where the keymapping for boxcutter completion action is? I have looked everywhere and have seen nothing that remotely resembles these default actions when in the boxcutter modes of operation.

Hmm. Will look in Preferences…

Thousands of preferences in Boxcutter... but I found it. It is under "input" within the settings. Property called "Preserve Alt". There are others such as Preserve RMB and Preserve LMB as well. This changes everything! So great!

Just signed up to say thanks to @Jeff for the "Preseve " thing. Really appreciated.


text:
Is there a way to copy constraints from one armature to another?
I have two armatures, all the names and the number of bones are the same, but constraints are configured for one armature, is there a way, perhaps some script to copy the constraints to second armature, without doing it manually, for example, when matching the names of bones?

Does this answer your question? How to copy constraints from one bone to another?

As far as I can understand, this script copies the constrains within one armature, from left to right, but I need a little different, copy all the constrains from one armature to another armature

authors: Алексей Беседин


text:
How to add stroke to a video mask
Is it possible to add a stroke to a mask created in the Movie Clip Editor?
I've created a mask in a movie clip that I use for blurring parts of a movie clip. I wish to create a thin black line lining/stroking the mask. So in the attached example there would be a black circle around the mask/blurred part.

You can create a border by creating a second circle, like a letter O. It will have to be in a different mask because the mask for blurring will have to stay as it is.
Then, in the Mask tab, check the Holes box for the border mask. This mask/border will have to be filled with color which you can do in the Video Sequencer.
In the Video Sequencer, go to Add->Color and it will add a color strip. After clicking the color strip, go to the Modifiers tab.
At the Add Strip Modifier drop-down, choose Mask. It will generate a new panel/section that says Mask. Click the down arrow then choose the border mask you created.
To be able to show the other strips below, go to the Strip tab, then to Compositing, then at the Blend mode choose Alpha Over. This will make the transparent areas 'truly transparent'.
Then you'll have to add your movie (with the blur) in the Video Sequencer by clicking Add->Movie. The movie should be below the color strip or border.
To rearrange the movie and border, go to the Strip tab then to Channel - it has arrows for moving strips higher or lower.
By the way, you can also add Blur in the Video Sequencer. So you can do the blur and stroke in one place.


text:
Weird mesh deformation for hollow object
I have a question, when I made a skull for a bird and made it hollow, it warps when I try to animate the thing, look-
Is there a way to animate it so the whole thing rotates when I move it in pose mode? I tried painting the whole skull with maximum weight painting and yet it still deforms, is there no way to fix this? Thankyou in advance for any help.

Its highly likely you have vertex points on the skull attached to other bones rather than just the top one. So you'll have to remove the influence of the other bones from the skull. If it's not that, then it's probably better to take a look at the file, unless someone else can diagnose.

As Monolith said, it means than some other bones have influence on this part of the mesh.
The easiest way to fix it is to select this part of the mesh in Edit mode, then go in the Properties panel > Data > Vertex Groups, and in the menu on the right of the vertex groups list, click on Remove From All Groups so that the vertices you've selected won't be part of any group anymore, and won't be controlled by any bone.
Now keep the vertices selected, in the vertex groups list select the group these vertices are supposed to be part of (i.e. group that has the name of the head bone) and click on the Assign Button.
Or to assign you can also switch your armature to Pose mode, select the object, switch to Weight Paint mode, select the head bone (it should be blueish), then paint with the brush (Mix option).

Thank you so much guys, this will definitely help me out. I'm so glad I asked, this is the best advice I've gotten in a good while. You guys are the best!


text:
Trying to make two softbody spheres be connected
I'm not entirely sure what I am asking for but I do know there probably is a term for it, if anyone knows the answer or could tell me what I am looking for that'd be great.
See, I want to take two soft body physics spheres and put one inside the other, and have it react when the bigger sphere collides with say- a floor, but not exactly the same amount. Both spheres will be clear, and the finished product will resemble a cell or amoebae.

Srry for the late response, I forgot to follow up on this one, but apparently parenting the smaller object to the bigger one doesn't work...

Should I remove soft body collision from the middle sphere or something? I think there is a way to have both be soft bodies and one be inside the other without issues but I can't figure out what.

Thank you anyway... It's the thought that counts.


text:
How can I make this astronaut's oxygen tube collide with the astronaut?
Okay, so I got these two rigs I made in blender. One is a rig hooked up to empties and a set of vertices so that the rig will react to gravity. The other is a rig for the character herself, I named her Myrtle on another note. So I rigged her and the rigs work fine in fact better than I expected, the main issue is the helmet and backpack have a oxygen tube running between them that is reactive to gravity but I can't figure out how to make the tubing's mesh stop before clipping into her arm or body.This is before I run the simulation:
And this is when I push play:


text:
Astronaut I made has a physics reactive armature, how do I make the hose collide when it hits the astronaut
So, I made this astronaut in blender, I named her Myrtle. And I followed this really good YouTube tutorial for making an armature that deforms in reaction to physics like gravity as well as deforming the mesh. The armatures work wonderfully, actually perfectly. My main issue currently is that I can't get the air hose to collide with the astronaut's arm and body, it just passes straight through it.
It looks like this before I press play in blender:
Then when I press play it falls down and straight through the arm and into the body:
I'm not sure how to set up collisions or if because I added gravity to my armature for the air hose if I could even do so, if anyone is wondering what tutorial I followed I followed this YouTube tutorial: https://youtu.be/c11l2o5uCQs
I can't figure out how to make the hose less flexible either, I want it to merely react to gravity and sway when the character walks runs etc. But it actually is too string like when I add cloth physics to it.

Like your character, +1 by the way.

oh, you accidentally posted this question twice.

Yeah, I first posted it in the wrong area, I reposted in this one in what I believe to be the correct category, I'm sorry about the spam. As for what version of blender I'm using, I am stubborn and still using the outmoded blender 2.79 any idea how to make my astronaut's oxygen tube collide with the mesh of the arm and body. I don't know if following that YouTube tutorial and making the armature respond to gravity will affect the mesh's ability to collide with other meshes, currently the oxygen tube just passes through the arm and body.

not sure, but i hope you can find an answer.  I haven't watched the video, but could you tell me generally what you did to make gravity effect it?  was it rigid bodies?

The YouTube video explains it better than I ever could, but I'll try anyway...

Basically I created the mesh for my object that I wanted to react to gravity

Then I created a mesh of just vertices with connections but no faces in the length of the mesh, as close as possible to the center of the mesh I wanted to deform.

And I went and paired empties, 'spherical empty objects' to the vertices that were in the mesh that I'd apply the gravity to. Then I added an armature, made the mesh a child of the meshes without faces, then parented the mesh without faces to the armature after applying cloth physics to it.

wow, that's a pretty hefty simulation.  I'll probably have to watch the video :)

For a hose, you could use a softbody simulation on a string of edges in place of your armature, with a Skin modifier to give it thickness - similar to https://blender.stackexchange.com/a/98438/29586. This should allow it to react to gravity while also being able to react to collisions.

I just thought of something, if this is a cloth simulator, it should react to collisions.  have you tried adding a collision modifier to your astronaut?

Thankyou that sounds exactly like a perfect answer. I will try that and update you if it works. :)

As far as adding a collision to my astronaut I'm pretty lost the functions aren't very clear about how they function, I'm using blender 2.79 if it helps.

Strange... still doesn't want to react to collisions at all, I have tried all the suggestions given here but I must be doing something wrong, it still passes through the astronaut's arm and body.

It didn't work despite me adding collisions to the astronaut, and the softbody physics made the air hose liquify when played back on blender. If anyone has any ideas that might help I'd love to hear them pls.


text:
Questions About Smoke?
So I am brand spanking new at blender and just learning the ropes. I believe everything about my smoke is set up fine, but EVERYTHING in the scene is getting rendered (like the smoke domain before I messed with the nodes from seeing a similar problem). Could anyone give me a hand as I know basically nothing about rendering in blender?
Here is the .blend for anyone looking :)

Hi. Please make your title specific to the question you are asking, not just the general topic.

While you are at it, also add actual info to your question like screenshots, settings, and other details that may hep diagnose the issues

For the smoke domain material, I believe that a Principled Volume would work, feed it into the volume input of the output node.  Change the density to 0.  Delete the default diffuse shader.
Or you can make the smoke domain invisible like this: How can I make an object invisible when I render in Cycles?


text:
How do I change the End Frame in an animation without changing the max frames in other animations within a character?
In the dope sheet I selected Action Editor in the dropdown menu to animate my character with multiple different animations and they all take up different amount of frames. But when I change the End Frame of one animation, it changes all the other animations' End Frame to the one I inserted to that one animation.
Is there a way to change only one animation's End Frame?

No.
The start frame and end frame are properties of the scene. That's is why they're located in the scene section of the properties area. Each scene has its own (but exactly one) start and end frame.
Actions have no start and end frame. They are automatically starting on their first keyframe and ending on their last keyframe. If you add an action to the NLA editor these are the frames which are used for the length of the action. (You can still trim the actions used frame range in the NLA editor.)

You mean « They are automatically starting on their first keyframe »?


text:
2.8x - Recovering removed properties from 2.7x .blend files
I'm converting an add-on from Blender 2.79 to 2.8x (currently using 2.83.4), and unfortunately it relied on some properties tied to the Blender Internal render engine which were removed in 2.8. I've not had any problems recreating these for 2.8x, but I'm trying to find an a simple way to handle old .blend files which were built on 2.79.
Namely, I'm trying to recover the Material.texture_slots property which no longer exists in 2.8. I've tried searching for it after opening a legacy .blend file, and I've tried loading/linking a file in a script using bpy.data.libraries.load. But it appears that any properties without a 2.8x equivalent are always discarded once the file is loaded.
Is there any way to read these removed properties without requiring a user to have 2.79 installed? I'm trying to avoid a scenario where they need to pull down a new release of the 2.79 add-on, load their blend file(s) in 2.79, then run a script to copy the relevant BI properties over to the new custom properties I created for 2.8x, then save a copy of the blend file.


text:
Python to show one of objects by choosing
I have a question about Python. By the way, I'm a beginner of English and Python. I have a script to show Toruses from an imported txt file containing center coordinates. Thanks to this website, it was made and worked really well. But I'm facing another problem. Although all of Toruses are showed by the script, I would like to show one of them by user's choices and erase it and show another one if the user choose the another one. Or I would like to show the Toruses one by one by using the function of Timer or Animation. Sorry for this mess explanation, but I would really appreciate if someone helped me. Here is the script and some lines(Atom`s coordinates) from my txt file.
import bpy
import math
from bpy.types import Operator
from bpy.types import Panel

class MeshGenTool():
    @classmethod
    def main(cls, context):
        scene = context.scene
        objs = importFile(scene['File'])
        for obj in objs:
            bpy.ops.mesh.primitive_torus_add(
                location=obj[0], rotation=(math.pi/2, math.pi/2, math.pi/2))
            obj=bpy.context.scene.objects.active
            mat=bpy.data.materials.new('Torus')
            mat.diffuse_color=(1.0, 0, 0)
            mat.alpha=0.8
            obj.data.materials.append(mat)
            MyMesh = context.object
            Mymesh.name = "MyMesh"

class MeshGenButton(bpy.types.Operator):
    """Execute generation"""
    bl_idname = "object.simple_operator"
    bl_label = "Generate"

    @classmethod
    def poll(cls, context):
        scene = context.scene
        filevalid = (scene.File is not "")
        return filevalid is True

    def execute(self, context):
        MeshGenTool.main(context)
        return {'FINISHED'}

def importFile(File):
    obj_loc = ()
    obj_dia = 1
    obj_data = ()
    objs = []
    f = open(File, 'r')
    for line in f:
        if line.startswith('ATOM'):
            words = line.split()
            obj_loc = (float(words[6]), float(words[7]), float(words[8]))
            obj_data = (obj_loc, obj_dia)
            objs.append(obj_data)
    return objs

class VIEW3D_PT_Blank1_Blank2(Panel):
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'
    bl_category = "Import Atom Coords"
    bl_context = "objectmode"
    bl_label = "Import Coords"

    def draw(self, context):
        layout = self.layout
        scene = context.scene
        row = layout.row()
        col = layout.column(align=True)
        col.prop(scene, "File")
        col.operator(
            "object.simple_operator", text="Add items",
            icon='MESH_TORUS')

def register():
    bpy.utils.register_class(VIEW3D_PT_Blank1_Blank2)
    bpy.utils.register_class(MeshGenButton)
    bpy.types.Scene.File = bpy.props.StringProperty(
         name="File",
         description="Path of File to read from",
         default="",
         subtype='FILE_PATH')

def unregister():
    bpy.utils.unregister_class(VIEW3D_PT_Blank1_Blank2)
    bpy.utils.unregister_class(MeshGenButton)
    del bpy.types.Scene.File

if __name__ == "__main__":
    register()

CRYST1   65.961   65.961   65.961  90.00  90.00  90.00 P 1           1
ATOM      1  N   GLN X   1      32.110  46.350  52.070  1.00  0.00
ATOM      2  H1  GLN X   1      32.470  45.850  52.870  1.00  0.00
ATOM      3  H2  GLN X   1      32.931  46.641  51.559  1.00  0.00
ATOM      4  H3  GLN X   1      31.568  47.112  52.451  1.00  0.00
ATOM      5  CA  GLN X   1      31.200  45.480  51.230  1.00  0.00
ATOM      6  HA  GLN X   1      30.402  45.041  51.829  1.00  0.00
ATOM      7  CB  GLN X   1      30.390  46.250  50.180  1.00  0.00
ATOM      8  HB1 GLN X   1      30.811  46.160  49.179  1.00  0.00

If you show some object (a torus) by user action it seems like a [game] description.  You may want to search Blenders game engine or some other game engine.
The
hide_render and hide Python attributes, the eye and the camera icon in the outliner window
can be set to True or False to assist you in your goal.  Or you may insert keyframes or individual as scripts opposed to frame change handlers.

BSE Link Show and Hide child objects along with Parent
Your code in your question may benefit by placing all the items in a (group) which can source of an iteration in Python (for loop) and used with other ideas later in this proposed answer.  A small number of copy/paste actions can be done manually with regard to your patience.
If you want to an animation with no user control I suggest you see the topic of [particles].  Particles have location and render visibility which may interest you or allow you to think about your task differently.  You may employ 1 or more Particle Modifiers.
If you do not want to use particles then with a script I suggest you use a frame change handler.
Please search
frame_change_post and
frame_change_pre

and modify the render visibility to True or False.
This proposed answer are high level remarks to guide you in the correct direction and (not) a tutorial.