text:
How to create an Empty of type Image and assign a picture with Python?
How can an Image-Empty be done with Python?
And how to set an image file on it? Object.data is None for empties, and there is no .image property on the object level either.

An Empty is created like a regular Object, but with None for its data:
empty = bpy.data.objects.new("My Empty", None)

It can be linked to the current Scene like any other object:
scene = bpy.context.scene
scene.objects.link(empty)
scene.update()

The origin is set using the standard .location property (you may also use .matrix_world.translation):
empty.location = (1, 2, 3)

To make this Empty an Image-Empty, change its .empty_draw_type property to IMAGE:
empty.empty_draw_type = 'IMAGE'

An Image datablock is then assigned to the Object's .data attribute!
img = bpy.data.images.load("path/to/image.png")
empty.data = img

Other properties available for Image-Empties are (UI / Python):

Transparency / Object.color[3]
Image Offset / Object.empty_image_offset
Image Size / Object.empty_draw_size

BTW: You can change the RGB colors (.color[0:3]) of the object to tint the Image, which is not possible via the interface!


text:
How to animate multiple lines
I wonder what would be the best way of animating multiple 2 dimensional lines in blender.
Lets say I have lots of line, that are parallel and have some sort of rule, kind of like a PCB board with hundreds of circuits.
The starting frame would be when nothing is visible and during the animation the lines would slowly build up from nothing all the way to the end forming the finished lines.
I have a couple of ideas that might work, but all include heavy hand animation, like:

grease pencil animation, drawing them one by one, converting to curve, then build up modifier
some dynamic paint hack

There maybe other more efficient methods that I don't know of and if so, please let me know.

What about using the Start and End bevel factors with curves?

https://dl.dropboxusercontent.com/u/2568/0001-0090.avi
that's based on your bevel advice. I like it.

You can use Curves and animate the Start bevel and End Bevel factors:

These options determine where to start the Bevel operation on the
  Curve being beveled. Increasing the Start Bevel Factor to 0.5 will
  start beveling the Curve 50% of the distance from the start of the
  Curve (in effect shortening the Curve). Decreasing the End Bevel
  Factor by 0.25 will start beveling the Curve 25% of the distance from
  the end of the Curve (again, shortening the Curve).

These settings are in Properties > Object Data > Geometry:

You can use a Curve Deform Modifier on a mesh and animate the axis that follows the curve. By animating it from 0.0 to x, the mesh grows along the curve. Scaling to 0.0 is a bit tricky because you get a flat object. Either set all scale to 0.0 for the first frame or animate the visibility in the outliner.

You could also use an array modifier with this

Another way is to use the build modifier.

The thing to note with the build modifier is it builds using existing geometry, that is displaying it one face at a time, so you most likely will want to increase your mesh resolution (or use subsurf modifier) to get a smooth animation. The main difference of the build modifier is the randomize option which allows you to have a line materialise over the entire length instead of drawing from start to end. If you are using curves that means turning up the resolution in the curve properties.

source: Stack Exchange

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

sort: votes


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Why does the collada exporter not export texture references?
I've been having trouble exporting collada objects from blender, so I stripped everything back and textured a single cube, and exported it.
This is a completely trivial model, one cube, with one material assigned to it, the material has a single 'g.png' texture assigned to it.
The exported collada data looks like this:
  <library_materials>
    <material id="Material-material" name="Material">
      <instance_effect url="#Material-effect"/>
    </material>
  </library_materials>

Where:
  <library_effects>
    <effect id="Material-effect">
      <profile_COMMON>
        <technique sid="common">
          <phong>
            <emission>
              <color sid="emission">0.2879998 0.2879998 0.2879998 1</color>
            </emission>
            <ambient>
              <color sid="ambient">0 0 0 1</color>
            </ambient>
            <diffuse>
              <color sid="diffuse">0.2163267 0.1845119 0.2121569 1</color>
            </diffuse>
            <specular>
              <color sid="specular">0.5 0.5 0.5 1</color>
            </specular>
            <shininess>
              <float sid="shininess">50</float>
            </shininess>
            <index_of_refraction>
              <float sid="index_of_refraction">1</float>
            </index_of_refraction>
          </phong>
        </technique>
        <extra>
          <technique profile="GOOGLEEARTH">
            <double_sided>1</double_sided>
          </technique>
        </extra>
      </profile_COMMON>
      <extra><technique profile="MAX3D"><double_sided>1</double_sided></technique></extra>
    </effect>
  </library_effects>

This seems to be missing the texture data associated with the object.
By comparsion, exporting a wavefront object generates this .mtl file:
# Blender MTL File: 'basic.blend'
# Material Count: 1

newmtl Material
Ns 96.078431
Ka 0.000000 0.000000 0.000000
Kd 0.790000 0.790000 0.790000
Ks 0.500000 0.500000 0.500000
Ni 1.000000
d 1.000000
illum 0
map_Kd g.png   <----- ie. Blender is aware of this texture

So... is the collada exporter for blender just broken, or does it require some kind of special config in order to function correctly?
If the latter, how/what is required to make this work?
(NB for what it's worth, the UV coordinates are exported in the .dae, abit they obviously are completely useless without a texture assigned to them; I've also tried adding two different textures to see if the exporter needs that because it naively assumes 'one texture = don't bother, it's one texture for the whole model'. That didn't work either)

Start with the default cube. Ensure you've created a material or use the default material already created. Assign a texture to it as a diffuse image, say "lava.png". The important point here is to assign your object texture via a material. There is another way to directly texture mesh faces without a material but you still need a default material to get the Collada export to recognise textures, so I suggest going with this approach. If you export as Collada format now, ensure you select "Include material textures" checkbox in the export options. This will produce something along the lines of following XML element in the export file:
<library_images>
    <image id="lava_png" name="lava_png">
        <init_from>lava.png</init_from>
    </image>
</library_images>

But the library effect element will look something like:
<library_effects>
    <effect id="Material-effect">
        <profile_COMMON>
            <technique sid="common">
                <phong>
                    <emission>
                        <color sid="emission">0 0 0 1</color>
                    </emission>
                    <ambient>
                        <color sid="ambient">0 0 0 1</color>
                        </ambient>
                    <diffuse>
                        <color sid="diffuse">0.64 0.64 0.64 1</color>
                    </diffuse>
                    <specular>
                        <color sid="specular">0.5 0.5 0.5 1</color>
                    </specular>
                    <shininess>
                        <float sid="shininess">50</float>
                    </shininess>
                    <index_of_refraction>
                        <float sid="index_of_refraction">1</float>
                    </index_of_refraction>
                </phong>
            </technique>
        <extra>
            <technique profile="GOOGLEEARTH">
                <double_sided>1</double_sided>
            </technique>
        </extra>
        </profile_COMMON>
        <extra>
            <technique profile="MAX3D"><double_sided>1</double_sided>
            </technique>
        </extra>
    </effect>
</library_effects>

Note that the diffuse element defines a colour rather than an image reference. This means there's no 'link' in the Collada file between the lava.png and the diffuse component of the material associated with the mesh.
The missing step relates to the coordinate mapping technique used. Go to the texture panel for the lava.png and find the "Mapping" section. The coordinates entry is likely set to "generated". Change this to UV and export again with "Include material textures" and the diffuse entry will now reference "lava_png-sampler".
Something like:
<library_effects>
    <effect id="Material-effect">
        <profile_COMMON>
            <newparam sid="lava_png-surface">
                <surface type="2D">
                    <init_from>lava_png</init_from>
                </surface>
            </newparam>
            <newparam sid="lava_png-sampler">
                <sampler2D>
                    <source>lava_png-surface</source>
                </sampler2D>
            </newparam>
            <technique sid="common">
                <phong>
                    <emission>
                        <color sid="emission">0 0 0 1</color>
                    </emission>
                    <ambient>
                         <color sid="ambient">0 0 0 1</color>
                    </ambient>
                    <diffuse>
                        <texture texture="lava_png-sampler"/>
                    </diffuse>
                    <specular>
                        <color sid="specular">0.5 0.5 0.5 1</color>
                    </specular>
                    <shininess>
                        <float sid="shininess">50</float>
                    </shininess>
                    <index_of_refraction>
                        <float sid="index_of_refraction">1</float>
                    </index_of_refraction>
                </phong>
            </technique>
            <extra>
                <technique profile="GOOGLEEARTH">
                    <double_sided>1</double_sided>
                </technique>
            </extra>
        </profile_COMMON>
        <extra>
            <technique profile="MAX3D"><double_sided>1</double_sided>
            </technique>
        </extra>
    </effect>
</library_effects>

This should then import, with the texture intact, into whatever you're using, e.g. Assimp or a modelling package/viewer.
Hope this helps.

Just for anyone else who finds this, the key here was: Go to the texture panel for the lava.png and find the "Mapping" section. The coordinates entry is likely set to "generated". Change this to UV and export again. (btw: I'm pretty sure this means the collada exporter is actually broken. Changing the UV coordinate type shouldn't have any impact on this)

I have exactly this problem, but in Blender v3.6 there is no checkbox option for "Include material textures" - what now???

I was having an issue when exporting DAE's to use in Aurasma. After hours of messing around and re-exporting I realised that the problem was that I'd set Blender to default to the 'Cycles' renderer (and therefore associated materials) and exporting DAE's with textures only works with materials created in 'Blender Render' mode. I'm not sure that this solves the exact issue above but it's worth checking out and/or it may help someone else who is trawling the internet looking for a solution to the same issue as me.

I'm guessing "Blender Render" mode is "EEVEE"? because then it makes no difference in my case

I found out that to export texture you need to have Principled BSDF Shader connected to the texture - this is the only way.
Links to blender source code:
https://github.com/blender/blender/blob/594f47ecd2d5367ca936cf6fc6ec8168c2b360d0/source/blender/io/collada/Materials.cpp#L236
https://github.com/blender/blender/blob/594f47ecd2d5367ca936cf6fc6ec8168c2b360d0/source/blender/io/collada/EffectExporter.cpp#L113
https://github.com/blender/blender/blob/594f47ecd2d5367ca936cf6fc6ec8168c2b360d0/source/blender/io/collada/collada_utils.cpp#L1319
https://github.com/blender/blender/blob/594f47ecd2d5367ca936cf6fc6ec8168c2b360d0/source/blender/io/collada/collada_utils.cpp#L1448

This does not really answer the question. If you have a different question, you can ask it by clicking Ask Question. To get notified when this question gets new answers, you can follow this question. Once you have enough reputation, you can also add a bounty to draw more attention to this question. - From Review

It will help other peoples... come on... People here are so rude... WTF

No, this is not solution at all at least with Blender v3.6 as I have Principled BSFD node there yet it exports Collada .dae file without any image refference in it - images node in the file is empty like this <library_images/>

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

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


text:
Geometry nodes: Falling Tetris blocks into position
I'm pretty new to geometry nodes and Blender in general.I've made a collection out of Tetris blocks in a 4x10 rectangle. Then I used a Instance to Points node on a plane to repeat this collection a bunch of times to get sort of a pathway. Now I would like to let the blocks fall "from the sky" (along Z-axis) into the ground position like you can see in the image and rest there. The animation should be offset in a cascading motion so that the blocks furthest away from the camera start falling first and get to rest position first.If possible the children of the collection should fall seperately from one another in a random order (like single Tetris blocks) but the overall motion should be as described above.
I'm a little bit lost right now in how to achieve this. I hope my explanation is clear, if not feel free to ask.
Bonus points would be if I could somehow randomize the pattern of the blocks a bit but that would be the cherry on top. ;)

UPDATE
new node setup for the changed question:

result:

you can do this with this node setup:

result:

Thank you it works as intended except the collections move as single units (looks like a stairway) whereas I would like the single children pieces to move little bit randomly. "Seperate Childern" on the Collection Info node is checked. The Random Value node in the Instance Index input deletes some blocks randomly which is also a cool look but not exactly what I was looking for.
.

Please update/edit your question with that additional wishes you have (although it’s a bit unfair to extend your question afterwards) but so others won’t waste their time. Thanks.

Okay sorry I'm new to this community.

i updated my answer

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


text:
Smooth Shading won't work and Shading looks weird
for some reason my shading looks extremely weird. The Topology is a bit messy in some places, but it shouldn't affect the areas  as much I think. I also activated smooth shading, but it doesn't really work. either with or without auto smooth. The Normals are all facing outside and I tried adding a weighted normal modifier, als well as recalculating the outside and merging the normals. Nothing worked and I'm slowly getting out of ideas. Does any one of you have an idea?
Update: The Shading issues seemed to be because of evee. I still got some issues when importing the model to unity, but more in the places where the topology is messy, so this should be better once I clean it up a little. Still don't have any idea, why smooth shading doesn't work.

Could you highlight which area looks strange to you? If you mean that banding along the front beneath the cushions, that looks quite normal to me, assuming you're using Eevee. If that's the case you'll need to play with your shadow settings in order to smooth it out a little bit. I recommend adding samples in the Render settings, but also looking at the shadow settings of each of your lights.

Thanks. in terms of the shading issues it really seems to be because of evee. Some parts still looks weird if i put the model into unity, but thats where the topology is messy, so that should be fixed once I clean it up. But I still don't have any idea, why smooth shading is not working

Two possible reasons here:

Normal map is set to sRGB instead of non-color data:

Custom normals option has been activated:

Clear custom split normals data in this case.

Thank you, much appreciated, but sadly both options didn't solve my problem

You were right, the normal map was set to SRGB, but sadly changing it didn't fix it

Nope, don't have custom normals activated

But it's definetly a problem with the normal map. Deactivating it made the shading work


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Why is the bottom Instance rotated wrong?
does anyone know why the bottom face of my object doesn't rotate correctly? It's supposed to look like the one in the second picture, but for this face it won't work. Changing the Capture Attribute from Face to Point worked, but I'm trying to make this a fractal and it's not working with multiple iterations. Any ideas on how to fix this?

I think you are only aligning the Z axis of the instance with the normal of the face and then rotating it 60º but that's not aligning the X or Y with any normal so you are starting with the default orientation, which in the bottom face's case will probably be different. I think you need another Align to Euler to vector with for another axes. I'm pretty sure I've seen this on a youtube video, I'll see if I can find it

"It's supposed to look like the one in the second picture" - and doesn't it?

@Cornivius After a lot of testing it sound like this could be it. PPlease let me know if you find it

What version are you on? It seems to work on 3.5.1:

Are you sure the bottom face is an equilateral triangle? If one of the sides is slightly longer the normals might not be what you expect

This maybe the problem. I couldn't get a perfect triangle, it's off by 0.001 degrees. It also seems to work by rotating the y-axis by 0.01 degrees, which is not really a pretty solution

I made that pyramid with a 3 sided cone. Then with the edge length setting ON, I lowered the top vertex in edit mode until all the edges were the same length as the base. It's not really a precise method with just 2 decimals on the length but maybe the resulting mesh works better with that node set up than what you did to make yours.
I find it weird that there isn't an 'Add tetrahedron' button or at least a checkbox to make a pyramid heigh consistent with the side length

Thank you, it is weird. So, i made it work with this, but my instance object is a little different and sadly it won't work with that. But thank you very much for your help!


text:
image textures won't show (on mesh which was a curve before)
I am trying to add some wood pbr-materials on some simple objects. I made some of these objects out of curves, which I later converted into meshes and then just filled them up and made them thicker in editmode.
Now: When I try to add image textures to these objects, only the average colour of the image would show, not even with one detail. Other objects with the same material but which are made out of simple cubes, work perfectly.
How do I make the imagetextures work on meshes, which where (bezier-)curves before, too?

could you please show how your UVs look like?

I added a picture. As it appears, the part which was made out of curves doesnt even appear on the UV Editor.

so what does it give if you unwrap this part again?

Could you please add the .blend file?

Sounds as if you may need to recalculate the normals.

works! If I go in Editmode, select a face which wont work and do "Rightclick -> UV Unwrap Faces -> Unwrap" it shows the texture normally! Thanks alot!


text:
Transfering UV Maps/Custom Normals to identical object
Not my model, it's just a custom job and this got me nuts.
I've been almost 5 hours trying to deal with this, I swear this was my last option to solve this problem.
I've got one object with perfect UV map but without Custom Normals.
And another identical object (same verts and faces) with perfect Custom Normals but without UV map
The task looks simple: just copy/paste/transfer the UV Map or the Custom Normals to the other object to make the perfect model.
But it looks impossible, at least by my knowledgement
What I've tried:

Ctrl + L > transfer UV maps
Tools > Data transfer UV/Normals
Magic UV > Copy/Paste UV
Magic UV > Transfer UV
Data Transfer modifier

None of them worked, the most close result was using Magic UV but didn't worked.
I'm using Cycles engine and Blender v2.79
Please help me! I really appreciate your time and efforts!

UPDATE
LukeD's answer is ok, but still having issues at the transferred UV map to the other model, look at this attachments:

Transfer UV Maps is working just fine.

Select object with bad UV map.
With Shift select one with good UV Map.
Press CTRL+L > Transfer UV Map.

Thank you, but still not working. Did what you suggested and still bad results, please watch the updated answer with attachments.

@Ermac Couple of things to note. Both meshes are not so identical. Look at te vertices count. Transfer UV is working fine but UV layout for second mesh is just bad. Removing Custom Normals doesn't help so there is something wrong with the mesh itself. Both have a lot, really lot Double Vertices. First one (decals) has some loose vertices even. Also calculating origin point to the center is nearly impossible to be the same on both. My advice here. Delete the one with custom normals and use Y.A.V.N.E add-on on the uv correct one.


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Relieve topology tension on planes and borders
I was prototyping a steel shield and everything was good until I had to carve holes in it. It was a simple task, but I've noticed something that I ever wonder how to solve it. The topology around those holes shows some glitchs and tension problems that I've never modelled.
So, how I've come to this (and most important) how can I solve this volume rendering problem?
You can see in the images below what I'm talking about. The yellow lines are for reference of what looks wrong. The only modifier I'm using is Mirror and for better render results I've set the normals to 60º in Auto Smooth.

Your help is really appreciated.

From what I know, this is more than likely a result of poor topology. Generally, whenever I make cuts into a mesh, whether it be circular or oval shaped, I try to use something made out of 8 verts. You're completely correcting in saying that they are 'tension points', and I'd hazard a guess that it is due to the tris and the smaller faces located around the edges of the cuts. I'll provide an answer later on the day, should hopefully resolve your issue.

Thank you for your comment, I know that I have some tris and ngons problems, but sometimes I find really hard to not use them or trying to properly make it on quads. I'll wait for a solution hopefully. Thanks again.

Creating fully quad based meshes isn't something, as far as I am concerned, that can be explicitly taught. Personally, I found that more and more modelling practice eventually allowed me to solve most topology problems. But I will do my best to outline the key problems with your mesh in my answer.


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Audaspace Game Property in Python script doesn't work as expected
So I made a little test using Audaspace lowpass filter in a python script template, modified a little by myself (I'm new in python, so it is very possible that I made a mistake). Everything are working well, except when I try to change the Lowpass filter value using a Game Propertie modified in game with logic bricks. The idea is to change the lowpass filter for an effect in a videogame (e.g. underwater, behind wall).
Does anybody have a solution, it would be really helpfull.
import bge
from bge import logic

import aud

cont = logic.getCurrentController()
own = cont.owner

logic.device = aud.device()
soundpath = logic.expandPath('//Sounds/Engine.wav')
sound = aud.Factory.file(soundpath)

handle = logic.device.play(sound.lowpass(own["Amount"]))
handle.volume = 1

Your mistake is in logic.device.play(sound.lowpass(own["Amount"])) you are missing the frequency value and the amount go from 0.0 to 1.0 (step=0.1)
From the Blender aud API:

lowpass(frequency, Q=0.5)
Creates a second order lowpass filter based on the transfer function H(s) = 1 / (s^2 + s/Q + 1)
Parameters:
frequency (float) – The cut off trequency of the lowpass.
Q (float) – Q factor of the lowpass.
Returns: The created Factory object.
Return type: Factory

Test this (i haven`t test it):
import bge
from bge import logic
import aud

cont = logic.getCurrentController()
own = cont.owner

logic.device = aud.device()
soundpath = logic.expandPath('//Sounds/Engine.wav')
sound = aud.Factory.file(soundpath)
fequency = 100.0 #Hz i assume
amnt = own["Amount"] * 0.1
sound = sound.lowpass(frequency,amnt)
handle = logic.device.play(sound)
handle.volume = 1


text:
metarig works perfectly, but generated rig doesn't work at all
This is a separate mesh (shoe) on my character. It is parented to the metarig and then to the rig created by Rigify. The rig works all of my character, including the other shoe which is fine. I have reparented this mesh several times and weight painted. It now works fine with metarig, but not rig. Why is this?

(Edit: screenshot with face orientation overlay added)
Here is a link to the file: https://app.box.com/s/p8tcsuy5i39fk5gc4o848x3dfpapkgf5

Hi. I've added a screenshot to your question with the Face Orientation overlay enabled. As you can see, one shoe is red. This means that the normal ones are flipped and the mesh is inside out and causing the problems. Go to Edit mode, select the mesh, and flip the normals (Shift+N (=Recalculate outside) or Alt+N > Flip). After this, the weights must be recalculated or painted again.

Does this answer your question? Rigify (2.8) - automatic weight incorrect and issues with weight painting

First thanks so much for responding. Must have something else going on because I did all that and it didn't help. Metarig works and rig does nothing to that shoe.

OK, now I got it to work. First I had to delete all vertex groups. Thanks soooooo Much!


text:
Light particles/Light streaks effect
I am trying to recreate an animation seen here:
https://www.youtube.com/watch?v=eTes6yYH4iU
However, I am unable to recreate the light lines seen in the video. I have achieved similar to wanted results in EEVEE, but I would like to do it in cycles. Example from Eevee:

I was wondering, how should I approach the problem to make it happen in Cycles.
Thanks!

Could you provide your Blender file using https://blend-exchange.com/, so others can start from the results you achieved already ? And could you describe what you would like to reproduce from the linked video, instead of leaving others to identify key features ? You are mentioning an animation, but show a static picture.


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Need help with character creation and clothing
I started learning Blender a few months ago, just as a hobby, and want to make a few animation videos. I don't worry about quality as I just want to create videos.
So far I am using addons (like building generator, urbaniq) to create scenes as I don't need to worry about render quality so a few issues here and there are ok. So far ready-made models are working well for me. But the only issue is with the characters.
Now I am starting into character animation and that's where I am confused. I require low poly characters for stories but all they need to look different and with different dresses. so I need

Multiple characters (males, females, children)
Different dresses
Different poses
Different animation

Now I am not sure if should I start from scratch in Blender and do everything there or if I can use a combination of other software like DAZ etc. Again I just want to create animated stories and not worry about quality just the bare minimum to get stuff done.

Too many questions at once.

DAZ like Daz 3D? I would not call these models low-poly. If you don't mind a low-poly style check out Imphenzia's tutorials (https://youtu.be/PTWV67qUX2k or this older one: https://youtu.be/1jHUY3qoBu8). Or Grant Abbitt here: https://youtu.be/iMar3keWaUo and Joey Carlino's tips. With some practice, you can model such characters quickly. Low-poly characters also have the advantage that you can model the environment in a low-poly style and it looks uniform and nice, and it's done quickly.


text:
Curved hallways
I am searching for a way, how to make hallways smoothly curved as on included screenshot. Or can someone recommend me the tools/modifiers I have to use and the process?
Adjusted screenshot so that you can see the details without having to be in a dark room:

Original screenshot:

Or can someone recommend me the tools/modifiers I have to use and the process.

What have you tried as far? What are you struggling with as far? Can you form a more specific question? Right now you are pretty much asking to be taught modelling and texturing. It's too much for a single answer. You should form a specific question in the title as well.

For a one-off, or arbitrary hand-built connections, Bridge Edge Loops would seem a reasonable tool for this:

... here seen linking simple extrusions of a profile made from a plane with its upper vertices CtrlShift
B bevelled.


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How to remove sphere in glass reflection?
I created the “glass” material and a sphere appears in its reflection, which I don’t know how to remove. I'm newcomer to Blender, can someone help me with this? I cant find info on the internet about it.

try to select glass and set Shade Flat from context menu

@Crantisz
I entered to Edit mode, selected all edges -> RMB -> Shade Flat
unfortunately it didn't help

Can you share the file? You can use https://blend-exchange.com/

@Crantisz

@Crantisz
I created a new project and made the same glass material. there is a similar problem

btw, if I increase the value of ior, then the sphere in the reflection becomes smaller, but then the transparency is lost

@Crantisz wow, you are principal developer at mts digital, I'm just trying to get to your work)) idk can I write here in rus

It seems a problem from using transparent and transmission at the same time. But I don't have a strong opinion why it is happened and how it can be fixed. So maybe someone else will answer.

No, it is an international website, but you can join my VK group if you want https://vk.com/blender_3d

ty @Crantisz, I subscribed)
I found a possible solution: instead of “Glass BSDF” I decided to create through “Glossy BSDF”, also in “Mix Shader” I added the node “Layer weight” with the value “Blend” = 0.3
I added the result above, please evaluate this solution to the issue

behind the top right glass (between the door and the wall) I added a red object to check the transparency of the glass, the object itself is visible, but the color is rendered black (probably due to the lack of lighting)

I want to add that you may need to Pack Resource Files and forward your blend file again. The image you used in your world property(quarry_4_pure_sky) is missing.

@OgunlesiTaiwo


text:
Fspy issues in Blender
I'm trying to setup my camera so I can start modelling this image...

So I setup my Fspy shot like so...

But when I start modelling the basic shapes they look positioned right in the camera viewport but are way off in reality. Am I missing something?

Thanks in advance.

Your x axis estimations, especially the bottom one, seem off.  Is that it?

@DaleCieslak I find it depends a lot on assumptions about what is or isn't an edge.  The left most Y axis in the fspy above is suspect because I don't know that those three abutments are aligned.  I try to stick to only continuous straight edges.  Also, holding the shift key while moving the points is critical.  I also turn 'dim image' off, but that's a matter of taste.  Sometimes I find using the box guide helps.  But mostly it's practice, practice, practice.

In the end I went with this solution from Marko Matosevic on the Sydney Blender FB page...
"Because you need to start with one face and extrude from there. If you are adding a secondary cube, you don’t know where that cube is in relation to the other cube."
Major brain fart from me, thanks Marko!

Yes, extruding from the first cube of course puts the second one on top of it. The real building has the cubes overlapping, but I guess that's not to hard to achieve after extruding.

Problems you will always have when working with photographs in fSpy are:

the photos might have lens distortion
things are not always perfectly straight in real life
you draw the lines not according to the real-world properties

For the last point here is something that @MartyFouts already suspected, maybe the building parts are not aligned the way you've drawn the lines. For the two green Y lines labeled 2 in your fSpy screenshot, here are images from different perspectives:

The problem you have is that your image has two vanishing points, not three. You have to properly set the principal point in such a case. In your particular case it should be lower to get the proper alignment for Z. As in the attached image (the orange dot, roughly placed on the car).

This is a common mistake people make using fSpy. Yesterday I released a complete tutorial on how to use fSpy (covering all its options). It presents how to deal with images having different number of vanishing points.
I hope it helps:
https://youtu.be/daiMOYR8GS8


text:
Mining Blade thoughts?
I have this mining machine to model and before I launch into the blade, just wondering if you have any advice on how I could easily model the blades, notice the red lines that show the curvature of them. And also the blade tube can detatch like with the green lines I have shown, any easy way to cut that out?

Thanks in advance.

The curved blades you could model like bottle threads? Have a look here: Converting bottle threads from diagram... and here: How to model the bottle threads?, Or use other hard surface modeling techniques. E.g. add a cylinder, then add plane (rotated, subdivided a few times, placed in the cylinder), add a Shrinkwrap modifier (mode Project) + a Solidify modifier to the plane to create a blade

Sorry for the delay, but spikeyxxx on the CGCookie forums had a good idea, ie use the Worm Gear (Shift A > Mesh > Gears > Worm) as a base and create it from that.


text:
Sculpting a gold mine off Google Maps
if I’ve grabbed this 3d data off Google Maps but it hasn’t captured the detail of how deep the mine is; is there a way to do that without affecting the texture map too much?

ie this is how deep it is really…

Thanks in advance

Maybe try the BlenderGIS addon to get the true height information and geographic data?

Yeah that's what I used and this was the result I got, which unfortunately isn't accurate.


text:
Sculpting out a crease from a posed character
if I have this simple character posed with Rigify to finally be a 3D print, how do I sculpt out the crease at the back of the arm so there’s no issues when it comes to 3d printing?

Do I have to got into edit mode and remove the unwanted faces that fold into that area manually or is there a sculpt tool that will help me?
Thanks in advance.

Yes you need to apply the Armature modifier, go in Edit mode and correct the topology to get rid of the inner faces. Sculpt won't help, except the Remesh tool if you're OK to use it (as it will change the mesh density)


text:
Blender’s scale for STL export for 3D Print
just trying to export a model out correctly for 3d Printing.
But when I send it to the printing company they say the scale is out by a factor of 1000000.
As a simple example, here’s the settings I have, ie settings are in mm, everything has had transforms applied, Blender’s Unit Scale is a 1.0, but when imported say into Cura it auto scales to 1000000% , am I missing something?

This may help with the setup.  https://www.youtube.com/watch?v=R-Vq2O-hvfo  I used it for my 3D printing setup and it works.  I use Prusaslicer which is based on Cura.


text:
Head cutaway animation - possible?
I've got a possible job coming up for our university for the language department where they'd like a cutaway of a head to see how the mouth and tongue work with word sounds. Kind of like this https://www.youtube.com/watch?v=Gsgv1m1a0Sc&index=3&list=PL5FCB12D7F83D2133 but in 3d so that the camera can rotate around the head but keep that simple cutaway look (ie solid walls and empty space not like this https://www.youtube.com/watch?v=KPEBlP2cbIQ&index=4&list=PL5FCB12D7F83D2133 since it's way too busy in look). I know the camera clipping plane kind of does this but doesn't keep that walled look.
Not sure how to approach this, any tips?

You could make a large hidden cube cover half the head. Then apply a Boolean modifier to the head using the cube to 'subtract' the part of the head you want cut away.
Just make sure the head has a high polycount so it doesn't distort noticeably much.

That just might work Sminch04, I tried it with a sphere and cube (with a solidify modifier on the sphere) and it seemed to work well, especially when animating the cube moving around.

Hmm tried it with the BlenRig model and the boolean works to a point, if I move the cube closer to the front of the face then the boolean stops working see images...http://twistedpancreas.com/3d/character/cutaway_001.jpg http://twistedpancreas.com/3d/character/cutaway_002.jpg

You could set a background image and trace the contours using extrusion modelling (I startet with a plane).

After that you would add a few Shape Keys for all animated parts:

Add key frames of the Shape Key's values RMB with mouse over the value slider.
Quick result:

To finish you would extrude the flat model and perhaps add a bevel modifier.

Thanks stacker, I'm after a more 3d rather than 2d look though, ie I can rotate around the head and still have that cutaway look. Sminch04 below seems to have the answer I'm after though, but thanks for the reply.


text:
How do I make a cloth like this in the air?
How to make a cloth still in air without anything to interact with

Hi Simran. I know you are new here. But we cannot look in your brain and know what you are thinking so please tell us as detailed as possible what you want to do. You can edit your question by clicking on "edit". Else you gonna risk that your question will be closed soon. This is a pretty frustrating experience. Do you want to make an animation? Without interacting anything -> how should it "fly" then? So i think you mean not interacting with obstacles? If you wanna make an animation you can work with force fields. But because i don't know what you want...i won't write an answer....

No I don’t want an animation, I just want to make a stationary 3d model that looks like a cloth thats in the air like this. Thank you for your time.

You can create a plane, subdivide it, give it a Cloth simulation, select the left edge and assign it to a group that will be the cloth Pin Group, enable the Self Collisions option, create 2 Force Fields: one Wind and One Turbulence, play the animation, stop it at the frame you want and apply the Cloth modifier:

The other solution would be to use the same plane but sculpt it with the Cloth brush, which would give something like that:


text:
Strange artifacts in render (in viewport render not showing)
I have a huge problem. I have an object with some holes. In viewport render there's all good, but when I render a frame, there're some artifacts.
I tried fix the mesh by shading smooth/flat, recalculate normals, set normals from faces and nothing work. My mesh was imported from .STEP but I connected faces.
CYCLES, Blender 3.0
Someone could help me?
Best regards
BLEND FILE: https://we.tl/t-08ebCxzBan

please provide blend file.

I've just provided blend file

my guess is that this is caused by your topology and using booleans, you used 1 big plane and cut all those holes in it right? Boolean don't work that easily as especially they can create these lines (why? Because your topology is a bunch of n-gons with non uniform scale, it simply doesn't work at all) what you need is to either use low poly booleans and clean it manually or clean this mess manually (I tried to fix it with better topology but personally I would suggest to go back before you applied bool, subdivide that plane into smaller grid and the try to apply it

@MikoCG unfortunately I modeled it and did not cut it out. I got the finished model in .STEP and used the conversion to .STL mesh. So it is not necessary to undo the breakdown at the moment, I need something to do in the mesh

i had no problems rendering it out at 3.2 [1]: https://i.sstatic.net/9Kgy4.png but same on 3.0 ...so i would suggest using 3.1 or 3.2 if possible. You should file a bug report....[1]: https://i.sstatic.net/stKBB.png

@Chris Thanks so much! I've downloaded 3.2 version and it was fixed :)

You are welcome


text:
Blender 3.0.1: Can't Move Objects in Object Mode
I know this has been asked and "answered" elsewhere, but still...
I'm using Blender 3.0.1-2 in Arch Linux, and I'm unable to transform an object unless I'm in edit mode. The only exception to this is the camera and light source, which I can grab and move around.
I've searched around for answers to this issue and everything points to unchecking the origins, locations, and parents checkboxes under Options>Transform>Affect Only, however, they are already unchecked. Also looking under Item>Transform all of my X,Y,Z coordinates for Location, Rotation, and Scale are unlocked, so should be editable.

Similarly, if I'm working with a plane or text, I can't just select the object press "G" and then a letter corresponding to an axis to quickly adjust it.
Is there anything else I'm missing?
Thanks for your help.

That is happens if you restore factory settings?

Ah just solved this exact same problem. Turned out to be an NVIDIA driver problem (weirdly enough). Basically, I wasn't using the GPU on my linux machine (I checked settings > details and saw that the graphics section said "llvmpipe" and not something about my gpu). To resolve this, I installed the nvidia drivers for it (sudo apt install nvidia-driver-515), rebooted my machine, and verified that my computer now uses my gpu. And now blender works fine. I have no idea how my gpu has anything to do with objects not moving in blender though.


text:
Taper not working on beveled object
I have a line which is bevelled with a circle to make a cylinder. I want to taper it with the curve on the right side. When I choose the taper object to be the curve, the cylinder dissapears. How do I use the curve to taper the cylinder ?

The file is available here.

it should work, please share your file: https://pasteall.org/blend/

uploaded here : https://pasteall.org/media/b/1/b148b525f4bca6f813112d0238169b80.blend

To add to Mqbaka and Chris answers, once you've applied the taper rotation and aligned it with the X axis, it looks like you need to switch your curve handle type from Vector to Automatic or Aligned (select its vertices in Edit mode and press V)

It's a problem with the taper object and the curve itself.
First of all, like @Chris says, your curves have non applied rotations and those always tend to mess things up.
Another problem is that your modeled your taper object in the Z direction but Blender takes the taper value from the coordinates along the Y axis :

This is a screenshot from the official documentation about the taper object :

Look at what happens when I move one of the taper object's control points along the x axis :

With that said, your curves still responds to the taper in a funny way and I had real trouble trying to figure out how it was supposed to work so the best solution I found is to redo everything from the beginning without rotating the curves or transforming them in Object Mode. The steps are simple :
Add a Bezier Curve

Scaling everything by 0 on the Y axis, to get a cylinder

And add another Bezier for the taper object

You can now model your taper object but just remember that only the positions of the curve's vertices on the local X and Y axis will be taken into account :

Apply rotation to both curves before, then you will get:


text:
Is there a way to fix this weird shading?
Ok So I'm trying to fix this shading so everything connects Perfectly without the weird triangle/ dark shading spots. (using auto Smooth)
things I've tried:
recalculating normal's, Converting Face's to triangle's and back to face's,
merging vertices' to make sure nothing is overlapping, converting all face's to triangles, using shade smooth.
And I still Cant fix it.

If you know how I can fix this please let me know.
here's the file

hello, maybe share this part of your object? https://blend-exchange.com/

do you mean the file?

select the edges in the cavity and either mark them sharp, split them, or bevel them.

Marking them sharp didnt fix it bevels change the shape and i cant split them bc i need it to manifold or (water tight)

You could get rid of the triangles and revise the topology a bit, you'll have a good shading:


text:
Edit keyframe values from graph or dopesheet using Python
For short I want to make an addon which would allow to select keyframes from the graph editor (and eventually also from the dope sheet) and change their value at once using an input popup. And more complex options like incremental inputs and other stuff, but that's for later.
I did a flow chart of what I aim for the v1, if it can help you:

I'm struggling with the core action:
Set a value to the selected keyframes, from the graph editor.
My first tries were to basically edit some keyframe values in the graph editor and work from what pops up in the info editor as I usually do:
bpy.context.object.co[1] = 1

Which doesn't work on its own and returns:
AttributeError: 'Object' object has no attribute 'co'.
I also noticed this in the Python Tooltips:

I tried at least to just get a working line like
bpy.context.selected_visible_fcurves.Keyframe.co[1] = 1
bpy.context.active_object.animation_data.action.fcurves.Keyframe.co[1] = 1
But with no success.
I also tried to see how other people did on Internet and tried stuff like these:
def execute(self, context):
    for b in bpy.context.selected_visible_fcurves:
        b.types.Keyframe.co[1] = 6
    return{'FINISHED'}

Or :
def execute(self, context):
    for b in bpy.context.selected_visible_fcurves:
        b.types.Keyframe.co[1] = 6
    return{'FINISHED'}

I also saw lots of people actually replacing their existing keyframes by new ones with new values, but to me it seems to be a lot of instructions for very few effects, and I guess it will not perform correctly on large scale operations.
I may also indicate a few needs:

this should work on any kind of curve, no matter if it's a loc/rot/scale curve, a custom curve, ... So I cannot use any transform-specific code like I've seen several times.
ideally it should work on any selected keyframe, no matter if its a different curve, a different object, ... As long as it's in the graph editor and I can select some keys, it should work.

Thanks for any help!
Edit
Thanks to brockmann's answer I now can go further in my script.
I just have a couple more wonders:
Set the pop-up value from the active keyframe's value
Right now, the default value of the popup is 0 at first start, and then it keeps the last value used everytime it pops again. I would like it so that each time I call the popup, it shows the active keyframe's value.
So as far as my python skills can go, it means to find a way with blender's api to get the xy coordinates of the active keyframe and assign the Y to my-float_y, and put this procedure at the very start of the operator, right?
I tried this but it doesn't output anything I want:
    def kval(self, context):
        k_val = 0
        for v in context.active_editable_fcurve:
            for kv in v.keyframe_points:
                if kv.select_control_point:
                    x, y = keyframe.co
                    print("y key value is", y)
                    my_float_y = y
        return {'VALUED'}

How to change the UI
Right now it looks like this:

The cons are that it takes lots of screen-space just for a value, and it requires to set the value, press enter and then click the OK button.
I can kind of make it simpler by reducing the width because the value always overlays the text, but that's not enough:
It would be more efficient if it was a more direct interaction like i.e. the samples inputs:

Ideally I would want just something small and simple like this (but with a float):

When editing the value of the keyframe you have to set both handles as well. Example on how to set the value based on our famous Operator Simple template (should work for the dope sheet too):

import bpy

class SimpleOperator(bpy.types.Operator):
    """Tooltip"""
    bl_idname = "object.simple_operator"
    bl_label = "Simple Object Operator"
    bl_options = {'REGISTER', 'UNDO'}

    my_float_y : bpy.props.FloatProperty()

    def cpoints(self, context):
        ctrl_pts = []
        for c in context.selected_visible_fcurves:
            for k in c.keyframe_points:
                if k.select_control_point:
                    ctrl_pts.append(k)
        return ctrl_pts

    @classmethod
    def poll(cls, context):
        areas = ('DOPESHEET_EDITOR', 'GRAPH_EDITOR', 'TIMELINE')
        if context.area.type in areas:
            return True
        else:
            return False

    def invoke(self, context, event):
        wm = context.window_manager
        return wm.invoke_props_dialog(self, width=450)

    def execute(self, context):
        sel = self.cpoints(context)

        for k in sel:
            k.co = (k.co.x, self.my_float_y)
            k.handle_left = (k.handle_left.x, self.my_float_y)
            k.handle_right = (k.handle_left.y, self.my_float_y)
        return {'FINISHED'}

    def draw(self, context):
        lay = self.layout
        lay.row().prop(self, "my_float_y")

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

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

if __name__ == "__main__":
    register()

    # test call
    #bpy.ops.object.simple_operator()

Alternatively you can use an invoke_props_popup:

See: How do I get invoke_props_popup to work?

Oh boy! That's a huge answer, thanks! Now that I have a working base I can add stuff around. I just have a couple more questions about your code, see my edits.

posted right now ;) Screenshots took longer that I thought


text:
Set inverse Child OF constraints via python
A few years ago I used to be using a little script found here in order to reset every "Stretch to" constraints of an armature, in pose mode, even on unselected/offlayered bones  :
import bpy
    for b in bpy.context.active_object.pose.bones:
        for c in b.constraints:
            if c.type == "STRETCH_TO":
                c.rest_length = 0

It has been very useful, especially when you drastically edit the bones positions of an already finished rig (i.e. when you reuse the same rig for similar but different models).
I would like a very similar script, but with "set inverse" for CHILD_OF constraint.
But I barely know Blender's API and every try haven't got anything working nor going the right direction.
My last attempt looked like that:
import bpy

    for b in bpy.context.active_object.pose.bones:
        for c in b.constraints:
            if c.type == "CHILD_OF":
                context_py = bpy.context.copy()
                context_py["constraint"] = constraint
                bpy.ops.constraint.childof_set_inverse(context_py, constraint="Child Of")

And got this error:
Traceback (most recent call last):
  File "\Text", line 7, in <module>
NameError: name 'constraint' is not defined

I also got this proposition from another guy:
import bpy

for b in bpy.context.active_object.pose.bones:
    for c in b.constraints:
        if c.type == "CHILD_OF" and c.target is not None:
            c.inverse_matrix = c.target.matrix_world.inverted()

With this one, no errors returned, it executes properly but simply doesn’t affects the rig.
If someone could help me, that would be kind.
Edit: this is one of the tracks if followed, but hasn't worked for me. Also, it looks like it's for object mode and for active selection only, while I'm going for pose mode and effect on the whole armature.
EDIT 2: SOLUTION
A big thank to Konybravo for this piece of code:
import bpy

ob = bpy.context.active_object

# Take a copy of current layers
org_layers = ob.data.layers[:]

# Show all layers
for i in range(len(org_layers)):
    ob.data.layers[i] = True

for b in ob.pose.bones:
    for c in b.constraints:
        if c.type == "CHILD_OF":
            context_py = bpy.context.copy()
            context_py["constraint"] = c
            ob.data.bones.active = b.bone
            bpy.ops.constraint.childof_set_inverse(context_py, constraint="Child Of", owner='BONE')

# Reset back to orginal layer state
for i in range(len(org_layers)):
    ob.data.layers[i] = org_layers[i]

Working straight away, even on bones hidden in a layer. Yay \o/ And thank y'all for helping me those days.

The error tells you what is wrong: the variable constraint is not recognized, because you named it just c (for c in b.constraints:). So change your code to: context_py["constraint"] = c

Ok. So now i have this :
import bpy

for b in bpy.context.active_object.pose.bones:
    for c in b.constraints:
        if c.type == "CHILD_OF":
            context_py = bpy.context.copy()
            context_py["constraint"] = c
            bpy.ops.constraint.childof_set_inverse(context_py, constraint="Child Of", owner='BONE')

And it works, but only on the active bone. How can I make it work on the whole armature ? Even on offlayered bones ?

For override method try adding context_py["active_pose_bone"] = b in pose  bone loop.

Tried it, still only affects the active bone.

Toggle a constraint property
As mentioned, simply changing the inverse_matrix property does nought.  If another property of the constraint is toggled, for example the target it appears to work as expected, using the new value assigned to inverse_matrix
Test script, tested on simple example of single bone and default cube parent. Set cmd to 'CLEAR' for clear and 'SET' for set.
EDIT:  code to interpolate based on constraint influence when set.
import bpy
from mathutils import Matrix

context = bpy.context

ob = context.object
constraints = [(pb, c) for pb in ob.pose.bones
        for c in pb.constraints if c.type == 'CHILD_OF']

cmd = 'SET' # or 'SET'
for pb, c in constraints:

    if cmd == 'CLEAR':
        c.inverse_matrix = Matrix.Identity(4)

    elif cmd == 'SET':
        if c.target:
            M = ob.convert_space(pose_bone=pb,
                    matrix=c.target.matrix_world,
                    from_space='WORLD',
                    to_space='POSE')
            P = Matrix.Identity(4).lerp(M, c.influence)
            c.inverse_matrix = P.inverted()
    # toggle a property
    target = c.target
    c.target = None
    c.target = target
    #pb.constraints.update()

why is this so?  Constraint properties that are set by a user (esp via UI) update the data appropriately on change.
An operator for each has been  chosen to crunch the numbers , and handle the necessary updating.  Perhaps a patch to make the python attribute update on change, not sure..

A big thank to Konybravo for this piece of code.
Working straight away, even on bones hidden in a layer. Yay \o/
And thank y'all for helping me those days.


text:
How to use bpy.ops.ui.eyedropper_color
I need an eyedropper button in my UI.
My question is about how do I use bpy.ops.ui.eyedropper_color() correctly? I tried
layout.operator(bpy.ops.paint.sample_color.idname())

which nicely draws me a button on the UI, but has no function (but also no error message). I also tried
layout.operator(bpy.ops.paint.sample_color.idname())

which is successful, but automatically assigns the color to the active brush, while I need to assign it to my own prop. Furthermore, I need it outside the paint context. ...any ideas?

You want a color picker, right? If yes, see: http://blender.stackexchange.com/questions/6154/custom-color-property-in-panel-draw-layout, http://blender.stackexchange.com/questions/10665/how-to-make-interface-for-add-on-with-mutipule-colorpickers, http://blender.stackexchange.com/questions/6984/color-as-custom-property

hm no, that's not it... what I need is a pipette functionality which can be accessed directly by a button / hotkey, without having to open a color wheel widget.

Ok. What do you want to pick?

well, imagine you have a global hotkey, or a button on the menu bar or something like that. You press / click it, the cursor becomes a pipette icon and you can sample a color from anywhere on the screen (e.g. from a video in the sequencer, or from an RGB node's color field, just everywhere).
The cool thing: the eyedropper of the standard color picker widget (bpy.ops.ui.eyedropper_color, that is) is doing exactly what I want. I just need it outside this widget.(which doesn't work so far)


text:
Lock rotation help
I know you can lock rotation, but not in-game. Is there a python for it, or a special edit or something. Please explain. Please be specific. Thanks!

Could you please put more effort into this question, e.g. add that this is a follow up of http://blender.stackexchange.com/questions/4905/a-different-kind-of-mouselook-script and give more context.

Is this for physics or animation? local or global axis locking? this question does not give enough info.

It's very difficult to tell what you're asking, and it seems like you didn't make much effort to craft a well-asked question. Please improve it, or it will be closed.

I understand the question as follows:
You want an object's rotation to be locked in game engine runtime.
Here's how I would solve the problem.
(1). Choose the object you want to work with. The freezing will only work on that object with this solution.
(2). Go to the logic editor and make a Property sensor of type Boolean. It shall be named "Perm". Activate pulse triggering and set the frequency to 0.
(3). Create a game property of type "Boolean" named "Lock" that is initially set to false.
(4). Make a "python" type controller in the logic editor and connect it to the Boolean sensor Perm. It shall be named "LockXYZ"
(5). Make a sensor of your choice that will set the boolean to true when you want the object's rotation to freeze. The sensor shall be named "Atog"
(6). Create a Property actuator that connects to Atog. This actuator will set Perm to "True".
(7). Open the text editor and create a new text called "LockScriptXYZ.py"
Paste the following in "LockScriptXYZ.py":
import bge

cont = bge.logic.getCurrentController()
own = cont.owner

own.worldAngularVelocity.x = 0.0
own.worldAngularVelocity.y = 0.0
own.worldAngularVelocity.z = 0.0

(8). Choose the script "LockScriptXYZ.py" for the python controller "LockXYZ"
That should do it.
I don't know if this was what you were looking for, but at least it's specific.


text:
Bone not able to be named?
I have a quick question: when I was making some adjustments to my weapon, I removed a vertex group because the bone was lost (I don't know how), and I basically made a new bone. I used weight paint and set it all up, and tried to finish it by naming it the previous bone's name. It keeps adding .001, .002 (, etc) every time I try to name it. Why?

The old bone is still there it is on another layer to see all armature layers go to Properties_Editor->Data->Skeleton and select a layer (or hold shift and select multiple) :

to move the bone to another layer you select the bone from the view(if visible) or from the Outliner ,then go to Properties_Editor->Bone->Relations->layers and select a layer :


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How to add roughness to a surface using modifiers?
I'm trying to make a roughened parchment-like material. I don't want to just use a texture, because I want to take a low-angle shot that lets me see the actual bumps in the surface.
I currently have the parchment represented using a single plane mesh. Is there a modifier I can use to deform the mesh in order to add roughness to it?

Yes, though you'll probably want to use two for maximum effect; I recommend applying a Subdivision surface modifier ('Simple', not 'Catmull-Clark'), and then applying a Displace modifier. If your geometry is sufficiently complex it should work fine.
The Subdivision Surface modifier adds vertices to your mesh, then the Displace modifier uses those vertices to add the roughness you're looking for.
Before Modifiers

After Modifiers

You can, of course, use different settings for the Displace texture if you want to achieve different kinds of roughness.

One thing I would suggest, is to use an image of parchment for the displacement texture, as it will come out more realistic.

I don't want to just use a texture, because I want to take a low-angle shot that lets me see the actual bumps in the surface

Since recently, you can use a texture and have actual bumps. This works in combination with Cycles only, and makes use of the Material's Displacement property.
First, you should use the Experimental Feature Set in the Render panel:

Add a Subdivision Surface modifier and enable Adaptive:

The trick here is that, by using Adaptive, the size of subdivisions will be dependent on how much the surface is close to the point of view. So you'll have each screen-space pixel displace independently from the neighboring ones, but without the need to subdivide the whole mesh by the same amount.
In the Node/Shader Editor, plug the desired texture into Displacement. If Blender>2.80, you should use a Displacement node, otherwise (2.79) just plug the height in the Material Output.

(If Blender 2.79, under Material > Settings set Displacement to "Both")

The bumps are now real, i.e. affecting the geometry, but non destructive, i.e. not affecting Edit mode vertices. In the gif, the geometry is just a 4-vertex plane:

Once your surface is subdivided with sufficiently small faces, you can use Mesh Tools -> Deform: Randomize to add roughness. Fine-tune using the tool parameters shown below.

My result:

If you prefer to have bumps instead of spikes, you can again Mesh Tools -> Add: Subdivide (with four or five cuts) and select Smoothness = 1.


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How to quickly do a clay render?
Sometimes, I find that it is useful to do a Clay Render for my model, where all of the materials render with a single common "clay"-like material (see example image below). In the past, I have done this by:

Selecting all of my objects by using the A hotkey
Manually deselecting the World object, camera, and lights in the Outliner
Linking materials using Ctrl+L
Manually setting to the same material in the Properties>Materials menu
Render like normal

When I was done with my Clay render, I would revert to the old version by pressing Ctrl+Z a few time. However, this is a rather clunky solution, since I can't make any edits in the clay version without losing my old materials/textures data.
Is there a better way to do Clay renders, either with an addon or through some other technique such that I can make edits to my model and not lose my materials? If at all possible, I would like a single setting that allows me to quickly toggle clay-mode on and off in the same file.
Example "Clay Render":

I think clay render is also available for cycles, it's already included in recent blender version and it's easier to use than the wireframe addon. BTW Gwenn did you answer your own question?

@micgdev It's perfectly fine to ask and answer your own question(s).

In the Properties area, Render tab, Layer group, there's a setting to override every object's material:

As of Blender 2.8x there is a new Override panel as part of the View Layer Properties:

Note that this only works in Blender Internal. In Cycles, there is no 'Light' option, and the 'Material' option ends up overwriting Emission shaders.

@Gwenn, unless your using regular lamps instead of emission shaders. I use this method even in cycles.

@Gwenn It also does not override environment lighting (coming from HDRI enviroment map for example).

You can use an "Ambient Occlusion" shader fot the clay material in Cycles. Mesh based lights might get lost, but since "Ambient Occlusion" does not use lighting, you still will get a nice geometry preview.

The short answer is that it depends on which render engine you are using.
Cycles: Wireframe addon
The 'Wireframe' addon will allow you to toggle clay materials on your objects using the 'Object Tools' panel.
To use the addon:

Download the addon from this site
In your User Preferences>Addons view, choose 'Install from File' at the bottom of the screen and select the addon file
Select all objects by pressing A then deselect emission lights in the Outliner
In the 'Object Tools' panel on the left-hand side of your screen, scroll down to 'Setup Wire Render'
Check 'Selected Meshes' then press 'Apply Materials'

Result:

Blender Internal: Clay Render addon
The 'Clay Render' addon adds an option in the Properties>Render menu that allows you to quickly toggle clay on and off.
To use the addon:

Download the most recent version from this site
In your User Preferences>Addons view, choose 'Install from File' at the bottom of the screen and select the addon file
In the Properties>Render>Render menu, check the box titles 'Clay Render'

Result:

Needless to say, Cycles is better.

I think clay render is also available for cycles, it's already included in recent blender version and it's easier to use than the wireframe addon. BTW Gwenn did you answer your own question?

Answering your own question is just fine on SE.

For Blender Cycles you can try this method. You don't need AO or lights. You only have to set a white diffuse material to all objects and use this node setup for your world:

This is the material for your objects:

So you can get a clay render like this:

Go to Properties >> Render Layers Button >> Layer Panel and select that clay material in the Materials list appearing there. That's all.

I've only skimmed your article, but unless I'm mistaken, you have to manually replace all materials with clay with this method. (Then afterwards undo to get your materials back.)

No, you don't. There is an option which replaces all materials at once. Firstly, you have to create the clay material in any object. Then go to Properties >> Render Layers Button >> Layer Panel and select that clay material in the Materials list appearing there. That's all.

Why dont you just select everything, copy it to a new file, make everything the same mesh (Control+J) (and of course excluding the lights and the camera) then make that massive mesh have the clay material? That way youre not doing anything to the original file


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Can't parent face rig to neck bones for test
Was trying to follow a video where he attached the root bone in super face rig to neck bones to rotate head. In edit mode I select the face rig but I cannot Shift-select the top bone of the neck rig (red check mark) to parent them together. The video shows it being done, but they don't explain how. Any help appreciated.

It would help to see the video (link?) Are you sure there are 2 armatures? You cannot parent a bone from one armature to another. This only works with a bone constraint. Or join both armatures first (Ctrl+J), then it should work.

Thank you for your reply. I did have two separate armatures and was able to combine them and parent the face rig to the neck bones.

Thanks to @Blunder for the comment on my question.
I did have two separate armatures and was able to combine them and parent the face rig to the neck bones.

Hope you don't mind the edit. You can click the tick on your own answer to mark the question as cleared up.


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How to control the rotation of particles following a curve guide
I want to achieve a line of ants walking on a curved surface. I decided to use a particles system set to emitter, with a curve guide to force them along a path.
I set the initial rotation of the particles manually by enabling "object rotation".

I want them to rotate according to the curve, instead they are maintaining their initial rotation.
I think this is what I'm looking for:

Curve Guide: If you use a Curve Guide and want the particles to follow the curve, you have to set Angular Velocity to Spin and leave the rotation on Constant (i.e. do not turn on Dynamic). Curve Follow does not work for particles.
https://docs.blender.org/manual/en/3.0/physics/particles/emitter/rotation.html#angular-velocity

But in the current version of blender (3.0.1) the options under angular velocity are different and there is no "Spin".
In this video (one year old) the guy seems to reach the result I'm looking for by enabling "dynamic" (the opposite of what the documentation says!)
https://www.youtube.com/watch?v=O0Zfjdf21X0&t=1435s
EDIT:
I've made big progress, it's almost working, but still there is something weird, so i decided to edit the question and add an example file:
https://easyupload.io/4b8kuz
In the 001 collection I set up the particles system and the curve guide, then I enabled "dynamic" and the particles start rotating the way I want:

But I want them to stick to the path since they are "walking" on a surface. I found two way to do that, by resizing the radius of the curve (collection 002), or by changing the "clamping" and "shape" of the force guide (collection 003).
They seem to bring to the same result, they clamp correctly to the curve, but the rotation is now messed. The particles seem to born with their rotation and then been "forced" by something:

Now if I go back in the particle setting I can kind of force the rotation by giving them some initial velocity and changing the "orientation axis" and correcting the phase. (collection 004)

Job almost done.
The problem is that if you look carefully at the motion, the particles are kind of glitching during the path, witch isn't great.
Was this the correct way? Can I do better?

in your result...apply rotation to circle.003 ...is this what you want?


text:
Border Rendering Is Not Supported By Sequencer
best to you all, please help me:

My computer: iMac 21.5 inch)
Environment: MacOS Monterey 12.7.3
Blender 3.6.5
working in this excellent program: Since 7 months ago

Photo of my screen:

Action: As usual without problems till today I tried my
￼  see informations:
Problem: No render animation but a note saying that border rendering is not supported by sequencer
Possible solutions I tried under suggestions:

I used the two commands Render Region and Crop to Render Region, and tried without.
I moved reducing and increasing percentage in resolution
I used the Option B

All without success to establish the order in this, nothing! Any suggestions?
Thanks in advance !!!

What happens if you uncheck Render Region and Crop to Render Region below the Format settings?

Hello and welcome. Please don't write in all caps in the title or body of any posts, it is the written equivalent of shouting, is harder to read and may be considered rude. Please use the [edit] button below the post to change you text into regular case.

“I tried my see informations.” What? I think you accidentally edited out some of the question while trying to add details.

What is Option B?


text:
I don't have any idea how I can do rhinoplasty surgeon
I already did a human model, but right now I don't know how I can render cuts in the nose like in this video. I will be really glad for any advice
Anatomy of the nose:

Rhinoplasty surgeon animation (cuts, removing & moving parts, creating & closing gaps, fading in and out of parts):

Full animation example:
https://www.instagram.com/reel/Csg0cG-oJlg/?igsh=azY5bGs0aHlyYjMz

Hello, your question is too broad for Blender Stack Exchange, what point are you precisely struggling with?

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. Don't make understanding your question rely on downloading a file, watching a video or visiting an external site. Use the builtin tools to upload images or gifs, along with thoroughly explaining the problem in written form so it can be indexed and searched for thus helping future visitors with similar issues.

Hello and welcome. As it stands this question is too broad to be answerable without requiring an extensive tutorial or description. You should show efforts towards reaching your goal, describing what you have tried and why it failed, so we don't risk recommending something you already know. The scope should also focus on a particular step you encountered an issue with. Describing the whole procedure from start to finish would be too lengthy to explain, and is beyond the goal of this site. If you could [edit] your post to focus on where you are stuck we can vote to reopen it.

Can you show what you have tried and where you are stuck now? In a nutshell: With Makehuman or another free tool you can create a human head. Then you need to model the inner parts of the nose (e.g. sculpting + retopology). With the shader of the skin you can make parts of skin invisible/transparent (Alpha input of the Principled BSDF). For the cuts use a thin block object that is not rendered with the Boolean modifier to make cuts. I guess at some point you need to fake things. E.g. use to 2 part objects, the original & one with cuts & gaps to control their visibility for the animation.

The deformations can be done with Shape Keys or an armature (or maybe modifiers).


text:
Material that emits light, but appears diffuse?
How can I have an object that emits light (using an emission shader) onto other objects, but when rendered appears to be diffuse (or any other shader for that matter)?
In essence, I want one object to emit light that shows on other objects, but that only itself receives light from other objects (not itself). Is this possible?
I tried doing this using Max/Add Shader nodes, but this just mixed in the "pure white" emission shader look with the diffuse shader I was using.

Use the Is Camera Ray output of the Light Path node to mix the shaders.

How did you get the Light Path node to only show the Is Camera Ray output?

@gandalf3, Toggle Hidden Node Sockets: Ctrl+H.

Ah, thanks.. learn something new every day ;)


text:
Geometry Nodes - Tilted Curve Boolean
I'm trying to create a shape that is the boolean difference of a tilted curve and a cube using geometry nodes.
If the curve is not tilted (twisted) - the result is quite smooth and clean and quite acceptable:

If the curve has a tilt (twisted) like this example curve:

Then the result has horrible jagged edges.

Even if I turn the resolution or resample the curve up to 128 or 256 it still looks horrible with jagged edges after the boolean operation.
Shade smooth OFF:

Shade smooth ON:

My node setup looks like this:

I understand it's not possible to do boolean operations using pure curves and there is some precision lost when converting to meshes.
There must be a way to get an acceptable result - how to get a cleaner result when doing boolean difference with tilted curve?

Update:
To help visualize what I think is happening I created a curve with cube instances on points which is similar to the quadrilateral. With no twist you can see the inside of the curve is smooth.

As soon as you introduce tilt to the curve it gets wonky.

i tried your setup and it looks fine on my blender 3.1. what version are you using? can you add  a Set Shade Smooth node before the group output and uncheck Shade Smooth then show a screenshot of how that looks for you

Could you share the .blend file?

I'm using Blender 3.2 - I shared the blend file as requested https://blend-exchange.com/b/RRdSZODZ/

I updated question to include shade smooth on and off. Both look pretty jagged and rough... the only way I can get it to look reasonable is to turn the curve resolution above 300 which is not practical in my opinion... when I zoom in with resolution 300 it's still zig zag jagged edge... I was hoping to cut these faces on a laser cutter and the zig zag edges make it pretty unusable.

The tilted curve faces are non-planar, and you're seeing their triangulation.  To improve things, you need to increase the controls on the profile curve-- the quadrilateral.  Resample the quadrilateral with a multiple of 4, like 32 or 64.  The more loops you cut perpendicular to the length, the more planar your faces, and the less that triangulation will matter.

I tried the idea suggested by @Nathan - Resampling the quadrilateral. It's definitely an improvement. I can't post pictures in the comment reply so I'll post it as an answer.

And here is a completely different idea to create this shape, including a cutout inside:

Here I first create a basic shape using two curves, which I scale accordingly.
I then extrude this in height.
I scale the upper face that can be selected in this way with an individual center, so that I achieve the shape you sketched.
Finally I separate only the faces, so that I can achieve a different smoothing of the normals.

I have no idea if this is helpful, but I found this to be quite an interesting variation.
(Blender 3.2)

wow... very helpful...

Credit to @Nathan for his suggestion of Resampling the quadrilateral.

I found if you try to adjust the Resample Curve Count while the node is connected blender crashes almost every time if you drag the slider for the number to adjust the count. I had best results if I adjusted the count then connect the node or manually type in a fixed number rather than scrolling through numbers. It accepted numbers that were not multiples of 4 and rendered OK but didn't handle scrolling OK.
I had to turn the count up pretty high (128) to make it look less jagged.

It still leaves some artifacts with and without smooth shading on but the result is less jagged and more usable so I consider this an answer.

If anybody is able to improve on this so there are no artifacts and it doesn't depend on turning the resampling resolution up really high to get a more pure result... I've thought about using a different shape as the Profile Curve in Curve to Mesh node - for example a Curve Line then solidifying the result but the normals get all wonky...

No matter what you do here, you will always (!) produce a weird appearance as long as you don't apply the Geometry Nodes Modifier. This is because the normals are not recalculated, and therefore, caused primarily by Mesh Boolean, will always produce completely unusable normals as long as you use Shade Smooth. And unfortunately there is currently no way to edit the normals directly in Geometry Nodes.

Here would be a variant that is not necessarily quite optimal, but at least it delivers:

A clean mesh
Neatly smoothed normals

The main changes to your example are that here I use a Curve Line as profile for Curve to Mesh, and clip this mesh with a Cube.
The resulting surface I send to the node Convex Hull, which creates a solid mesh from it.
Finally I apply the node Set Shade Smooth to the front faces (the curved faces).

This is a really good solution - the Convex Hull does a great job. One use case I can't make it work - If you imagine the curve like a letter D - the Convex Hull generates the straight line connecting the two endpoints of the curve. Making the shape so it creates a solid from the opposite side of the curve - the boolean object is like an extruded C shape.  Do you see any way to generate the inverse so the result is like an extruded C?

I was able to solve the problem of how to use the opposite side of the curve by adding a second boolean operation that operates on the output of the first boolean operation and it worked perfectly.

@stackzz Could you please create a sketch of the object (or objects) you ultimately want to create? I have another idea how you could possibly create such shapes.

I'm working on modeling a parametric boat hull. As far as making a sketch - your last answer below with red shading nailed it on the head. I have learned a lot from all your answers to this question. I'm sure it will be helpful to others also.

@stackzz Thanks, glad I could help you! Such a positive feedback makes me happy!


text:
How do I move the fingers?
I'm so new with Blender. How can I move the fingers ? Because when I'm trying to move only one finger, every finger moves.

hello, if you don't know how it works, maybe begin with the basics, i.e. how bones work, how to rig, inverse kinematics, etc...

It looks like a weight paint issue, like if every bone controls all the finger. Check this quick tutorial (youtube) to see how weight painting works and try to fix it by yourself.


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How to animate breaking model
This is the reference gif file. How can i achieve this in Blender. The breaking of the parts and disappearing later.

Any suggestion or Help. Thanks

To do that you need to use effectors, which are not built into Blender: there are many addons online like "Blender effectors" that could do that, maybe, but if you want to be sure try Animation Nodes.
It's a bit more complicated but very customizable.
In any case, you need to fragment the object beforehand (there are addons that do this too) and animate a plain effector (the one you see in the picture) over the object, apply a rigid body simulation to all pieces a make the effector trigger it when it get close to each piece. Also create a plane on the ground with a rigid body simulation, and set it as an obstacle.
Now you have the statue breaking into pieces and falling onto the ground: At this point animate the material color of the pieces from gray to the color you want, and finally to white, and make the effector trigger it as well when it gets close. Also animate the scale so that when they fall on the ground they shrink and disappear.
I don't know what your skill level is, and I was a bit vague, so if you have troubles working with effectors watch some tutorials on you specific effectors addon, since they may operate in different ways (also, make sure they support rigid body and color simulations before downloading them)


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What do various property highlight color overlays mean?
I have downloaded a free model for my current project and spotted those different colors on Scale, Rotation, Location, and other properties.
What do these different colors signify? What is the meaning of various possible color overlays on UI properties buttons?
The very same model after ⎈ Ctrl + C ⎈ Ctrl + V to my project file disappeared after a while.

Button colors reflect their respective property current animation state.

$\color{#777}{⬤}$ Grey/Theme Colored - Unchanged, static, non animated value
$\color{#3B1}{⬤}$ Green - Property is animated but not keyframed at the current frame (notice the diamond outline decorator to the right, click on it to keyframe at current frame)
$\color{#CC0}{⬤}$ Yellow - Property is animated and keyframed at the current frame (notice the filled diamond decorator to the right)
$\color{#C80}{⬤}$ Orange - Property is animated but the value is changed and no longer matches the evaluated/keyframed animation for the current frame. This happens when you changed the property but haven't yet keyframed the new value, it will jump back to the keyframed/evaluated value stored in the file if a new keyframed is not inserted, leading to potential data loss. Rendering will also reflect the saved state, rather that what you currently see in the UI. The stronger orange color should warn the user of its unsaved state.
$\color{#3AB}{⬤}$ Teal/Blue - Property is overridden. This is only for libraries, or linked data from other external blend files. It means the value differs from the predefined default stored in the remote library, and has a new locally set data override (notice the overridden arrow decorator to the right).
$\color{#92C}{⬤}$ Purple - Property has a Driver, an expression or simple math function that automatically controls its value according to input calculated from other properties/objects (notice the driven arrow decorator to the right).
$\color{#A00}{⬤}$ Red - Error state (used more frequently in modifiers or constrains). The property either has an invalid value, is disabled or is otherwise producing no visible effect. In the example below a Subdivision modifier has zero subdivisions both for viewport and rendered output and is thus effectively disabled for all intents and purposes. Despite no harmful errors occurring its name is shown red warning of its currently ineffective output.

Have in mind that all these colours are themeable though, so while most default themes shipped with Blender try to stay close to this scheme, third party ones could potentially look completely different under a custom configuration.
If in doubt check Edit > Preferences > Themes > User Interface > State for current palette.

It means that some keyframes have been created for the selected object and for these particular values. The light brown means that your timeline cursor is placed on a frame where you've created keyframes. The brown means that you've transformed your object (here the object scales) but haven't saved these values with any keyframes for the moment.


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How to debug low FPS with empty viewport?
I'm working on a big scene. From one point I noticed a drastic change in the viewport performance. To find out what was draining FPS I tried to exclude every collection from the layer and all the fancy staff from the viewport, ending with still low FPS, and really nothing happening.

Where can I look to solve this problem?
EDIT.
Here is how the file is organized:

The scenes are linked duplicate, each one with just one render layer.
If I try to deactivate ALL the collection from ALL the layer nothing changes. (Also tried to turn off the world shading setting)
What I'm wondering the most is:
Witch is the workflow to debug low FPS situation?
Am I correct assuming that the disabled collection shouldn't be evaluated?

search here for performance, viewport, fps -> there are lot of answers to this theme. What helps is: reduce subdivision modifier level for viewport, reduce objects, reduce resolution (in simulations)...and much more

I saw them but it's not my case. As you can see there are no vertices in the viewport...

to be honest...i don't see a lot because you didn't provide really useful information. We don't know whether you have more scenes than 1, we don't see whether you have more view layers...you didn't gave us any useful information to be honest. So pls provide blendfile or ALL needed informations. thanks.

I made an edit, let me know if some other important is missing.

Do you have any simulations going on like physics, fluids, smoke…? If yes, what settings have you there?

No simulations or phisycs. I have some particles moving on a curve guide instanced with particle system, baked on disk, then I have some particles instanced with geometry nodes.

This appears to be a known issue with disabled collections not neccessarily disabling their objects: #100754
There is a suboptimal workaround:

You can actually hide objects under a collection altogether with Shift + Left Click on the eye icon beside the collection. This action is also available in right click menu: Visibility > Hide All Inside and Show All Inside.


text:
How to configure Blender for 2D functions only?
I'm trying to convince a colleague of mine to switch from AutoCAD LT to Blender for structural drafting purposes. Even though Blender was not originally designed for 2D operation, it has the advantages of A: being free (as opposed to $1000+) and, B: having a lot of potentially time-saving functionality (the loop-cut operation alone could probably cut 5% off of drafting time, not to mention the array/mirror modifiers, etc).
However, my friend does not need most of Blender's 3D functionality, since structural drafting is almost exclusively done in 2D. In the best case scenario, I could configure him a stripped-down copy of Blender with all the exclusively 3D operations and hotkeys hidden, as well as rendering/materials/physics/etc. At the very least, I would like to configure Blender so that it is locked into orthographic top-view. How would I go about accomplishing either of these?

You want to setup the layout the way you want and save it as his startup.blend.
By adjusting his preferences you can delete entries for changing orthographic/perspective, view front/top/right. As you probably know the shortcuts you want to disable you can search for the inputs by key-binding.
The far extreme is to compile a custom build for him, with this you can also remove menu entries for changing the view orthographic/perspective and even hide the window types menu so he can't accidentally change the 3dview to something else.
Or you can just teach him to use what he needs, and say just ignore all the other stuff that you don't need to use. I'm sure he can handle exploring other parts of blender if he feels adventurous and knows you to call when he gets lost.


text:
Mirror an object via modifiers on a point(instead of a plane)
I would like to use modifiers to mirror and rotate an object.
Or simply, mirror on a point, not a plane.
Left on the image is the simple mirror modifier using the x-axis.
I want to have the situation on the right, where the object is mirrored and
rotated.
Red points correspond to each other.
It would be easier than copying and rotating the object, because I
want to model some kind of matching, point-wise symmetric chain links.

further examples of how to use the mirror modifier

Create an empty at the origin of your object.
Rotate it 180° relative to the object's rotation.
Add an Array modifier to your object, and disable all offsets.
Enable Object Offset and select the empty from the list.

Using the Object Offset can be a very powerful tool

Another Solution to this would be to use a linked copy, created with AltD and rotate that 180°. Linked copies share the same mesh.


text:
Convert Grease Pencil to Curve via Python?
I'm trying to piece together a script that will take a selected list of grease pencil objects and convert them to curves, one frame at a time. I'm calling upon the operator to convert the Grease Pencil object, but it's giving me a call back error.
    import bpy

##LOOP AND OFFSET THROUGH OBJECTS

# Get the current frame number
frame = bpy.context.scene.frame_current
start_frame = bpy.context.scene.frame_start

# Loop through all selected objects
for obj in bpy.context.selected_objects:

    # Move forward one frame
    bpy.context.scene.frame_set(frame + 0)

    #Convert Grease Pencil to Curve
    bpy.ops.gpencil.convert(type='CURVE', timing_mode='LINEAR', use_timing_data=False)

    # Set the object's render visibility property false
    obj.hide_render = True

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame=frame -1 )

     # Set the object's render visibility property false
    obj.hide_render = False

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame=frame + 0)

    # Set the object's render visibility property false
    obj.hide_render = True

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame=frame + 1)

    # Increment the current frame number
    frame += 1

Sometimes, you need to override the context. See more here: Convert gpencil to curve, python, crash
I was also getting context error when I didn't have an active object, so make sure there is an active object when you select them, or you can even automate setting the active object.
import bpy

##LOOP AND OFFSET THROUGH OBJECTS
frame = bpy.context.scene.frame_current
start_frame = bpy.context.scene.frame_start

# override context

win      = bpy.context.window
scr      = win.screen
areas3d  = [area for area in scr.areas if area.type == 'VIEW_3D']
region   = [region for region in areas3d[0].regions if region.type == 'WINDOW']

override = {'window': win,
            'screen': scr,
            'area'  : areas3d[0],
            'region': region[0],
            'scene' : bpy.context.scene}

# Loop through all selected objects
for obj in bpy.context.selected_objects:

    # Move forward one frame
    bpy.context.scene.frame_set(frame)

    # set obj to active object
    #bpy.context.view_layer.objects.active = obj

    # Convert Grease Pencil to Curve
    bpy.ops.gpencil.convert(override, type='CURVE', timing_mode='LINEAR', use_timing_data=False)

    # Set the object's render visibility property true
    obj.hide_render = True

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame = frame - 1)

    # Set the object's render visibility property false
    obj.hide_render = False

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame = frame)

    # Set the object's render visibility property true
    obj.hide_render = True

    # Insert a keyframe on the render visibility property
    obj.keyframe_insert(data_path="hide_render", frame = frame + 1)

    frame += 1

Hi, thank you for your response. This gives me an "index error list index out of range" Is it my for loop causing the issue?

Seems like that would be occurring when trying to access 'areas3d[0]' or 'region[0]'. Do you know which line the error occurs at after looking at the console output?

It's occurring at line 12. Really appreciate your help.

Well, areas3d should be nonempty if there is a view_3d area. In the console section where you can enter code, import bpy first and then try the following line print(bpy.context.window.screen.areas[0].type) and then try print(bpy.context.window.screen.areas[1].type) and then print(bpy.context.window.screen.areas[2].type). Look through your areas and make sure 'VIEW_3D' is there. Mine is at the 5th index


text:
Trouble with rigify: Can someone rig for me?
hellooo guuuys im new to the world of animation.
i use bforartists because its easy to use instead of that hotkey blender crap. so my problem is. i work on an female character and i have riged her with rigify. i set the bones like in the tutorials, than i click on "generate rig" and than the rig is messed up? why? and even when i select my mesh and than the rig with "parenting-automatic keying" it didnt work. the rig that i set properly is smaller and wider and my character doesnt move at all.
i tried everything! can someone rig it for me and send me back please? the bones are already set. and/or tell me what im doing wrong...
download it: https://www12.zippyshare.com/v/jMuDAKeH/file.html
attention: the girl is nude haha!

I'm voting to close this question as off-topic because it is a job assignment, not a question

A few things you should do differently when writing your questions to better your chanses of getting help. #1 don't start of by bashing blender (there really are a lot of blender only fans) #2 This is a Q and A site, we do not download files and fix them for people. Getting an answer saying what is wrong is a bit different. Questions and answers should help more then just one person. #3 please only use http://blend-exchange.giantcowfilms.com for blend hosting. (In 30 days your question will be completely useless because zippyshare will of deleted your file.)

We won't do your work for you. We will only help you with answers to your questions.
First thing I noticed, both your mesh and metarig have unapplied scales (and uneven for the metarig). They also have unapplied rotations. You have to apply your objects scales and rotations via ⎈ CtrlA before doing anything.


text:
How do I keep the shape resulted by the physics simulation
I am trying to simulate clay and found this answer: how to make a clay-like physic simulation?. The answer has a .blend file and I am trying to recreate it. In that .blend file a plane moves up-and-down, squashing a icosphere. When the plane moves up the icosphere keeps it's squashed shape. But when I recreate it in a different project, the clay returns to it's original shape. So how do I keep the shape resulted by the physics simulation.
(I didn't have enough points to comment)

You just need to stop the simulation at the frame you want it to end.
Change this value in the cache part:

You can set Edges > Plasticity to 100 so it will permanently deform. This way you don't have to end the simulation on a specific frame.


text:
Where to access calculated motion data after calling pose.paths_calculate
After calling bpy.ops.pose.paths_calculate(display_type= 'RANGE', range= 'SCENE', bake_location= 'TAILS') where is the motion data stored?
It is not context.active_object.motion_path, that one is used when calling bpy.ops.object.paths_calculate()
EDIT:
I found context.active_object.obj.pose.animation_visualization.motion_path, but this doesn't contain any points

It is stored in the bone itself


text:
How do I scale down a model while having the Normals lines' default size be scaled down accordingly with them?

Above is default.
Below is the one downscaled in size.
I've been having issues making the normal lines' default size retain their original default size upon rescaling models. This still affects it even after Applying all transforms to it.
I also have this issue when rescaling models/armatures as a whole in Blender, though it's mainly noticeable when it's rescaled to a significant degree (which I need to do in order to import into a certain other program I'm working with).
Edit: I should specify I'm seeking to make the normal lines size change be its default when exported to other programs, not just the ability to view it at the normal size but still retain the undesired size as its true default.

Don't know whether this will help, but In the viewport overlay dropdown you can check the 'Constant Screen Size Normals icon at the right-hand end of the Normals settings line. Let me know if you can't find it, or if you found it and it helped, and I'll add it as an answer.

Not able to find it within the dropdown. https://imgur.com/a/P3kDMlr
Using version 2.90.1 for reference (because of some add ons potentially not being compatible in newer versions)

Ah sorry. It looks as if it was added in version 3.0. It's not in LTS version 2.93 either. :^(

I could try out the latest version and see what results it gives there at a later time I reckon. Though there should still be a method fix for older versions I reckon right? Dunno how else models I've downloaded online would not have the same issue I have when scaling models in general (in older versions too).

To be honest I very rarely have normal display turneed on. I use the Face orientation overlay far more often to check the normal direction and have that quickly available via the quick menu.