text:
Cycles outlier removal for hot pixels - would that make it "biased"?
Even with setting my sampling numbers pretty high (256 diffuse and glossy samples times 16 render passes with branched path tracing) I'm still getting the very hot pixels.   I read that this is caused by out-of-range sample values which the render engine never really blends in with other render passes,  almost like the pixel has NaN (Not a Number) as a value.  Or maybe it's more like a pixel has a value of 400, and no matter how many passes you average it with, it's still going to be really hot.
It seems that an engine should be able to filter out these extreme values, (like a median filter?) but on the other hand I hate doing something like clamping my render values because I need to keep the engine non-biased.  (this will eventually be for a research project and it's vital that it be good math and a non-biased render engine.  So maybe I'll need to purchase a very good non-biased engine.)
Am I correct that any method for removing outliers would then make it a biased render engine?  Biased or not, numeric accuracy in the final image is the goal, so maybe even if it is technically biased with outlier removal, it might still be more accurate?
I'm not looking for techniques, such as "just blur it in Photoshop" but more theory of the rendering engine.    Thanks very much for your help.
=== Update:  I've found that the bright blue noise (from my emitter sky dome?) comes strictly from the Subsurface Indirect channel.  I'll have to read up on subsurface scattering to make sure I'm not doing something stupid, but as strongly as this noise comes through, it makes me wonder if it's a bug in Cycles.

AFAIK fireflies are caused by samples which bounce through a improbable path and hit a very bright something (usually indirectly, as lights guide samples directly to themselves with MIS to mitigate this). They stick out because pixels around them never manage to get the lucky set of bounces required to hit the same bright something. I'm not a dev or a rendering expert, but I believe clamping counts as bias. As a possible alternative you might look at Luxrender or Mitsuba.

Thanks gandalf3,  that confirms what I had thought.  It seems that the ultra-bright pixels are more a bug in the rendering engine theory than in software.   Thanks very much for the link to the MIS info - it looks like this is what I will need to focus my attention on.

Try enabling multiple importance sampling in the settings tab in the world settings. I would then set the resolutions (I forget exactly what that slider is called) underneath it, to 1024. This should get rid of a decent amount of your noise. This basically throws more samples at the bright sections. Do you have any SSS in your scene? If you don't, you could probably leave out this pass entirely, but I don't understand why it would be there if you didn't have SSS.

SSS is typically quite noisy, but it's possible there is a bug. You might try posting a report on the tracker

After posting it as a bug on the tracker, tracker page    I learned that branched path tracing does not work with the indirect Subsurface channel.   So my cranking up the Samples for Subsurface did nothing for the indirect ss, leaving it very noisy at only 1 sample per AA pass.   The problem was that I should have left the Samples settings relatively low and leaned much more heavily on the AA Samples.


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Data visualization using Dynamic Paint /Particle System
I would like to visualize my Data in a efficient and individual style.
My Data is in form of a .CSV file and consists of 700000 data sets.
(later i want about 20 million to be visualized)
One dataset has three information: Longitude (X-Coordinate), Latitude (Y-Coordinate) and a Timelinevalue (Z-Axis).
I managed to create a vertex-cloud using the CSV-Mesh-Importer
Blenderartists CSV-Mesh-Importer.
The result is one object with my 700000 vertices...... So far so good.
But to make some kind of Infographic i want to use Dynamic Paint.
In the next step I:

animated  my cloud and pushed it through a plane (linear movement on Z-Axis).
subdivided my plane and set it to  Dynamic-Paint Canvas
set my vertices to Dynamic-Paint Brush
set Dynamic Paint Source to Proximity
Dynamic Paint Source - Paint Distance to 0.1

....no Result
If only i could set the Paint source to vertices.... ;-)
I had to convert all vertices into little triangles or rectangles (extrude 2x)
With the quadruple number of vertices i got a visualization.
....Not really satisfying

Is it possible to convert my datacloud into a Particle System?
Can I teach Dynamic Paint to read out the vertices of the object?
Should i try another solution?

Thanks
Silent_Bob

Can you elaborate 'individual style'?

Sure.
With ´individual´ i mean the visual outputs Dynamic-Paint offers:
-Paints
-Displacements
-Heatmaps
-Use of Color-Ramps
-Dissolving Paint

From description it's quite hard for me to understand if your question is a goal of your needs or only if your question covers your vision - to get something you know about it.

Is it possible to convert my datacloud into a Particle System?

Yes.

Create "New" particle system with your point cloud (brush) object selected
Setup the number of particles same as vertices of your "brush" object
Set Emit from "Verts" (uncheck "Random")
"Physics" set to "No"
In "Render" panel of particles properties check on "Unborn" and "Died"

From how many vertices point cloud consist? Just select object and see header of blender window (next to the logo - "Vert:").

From your screen it looks like vertices represents some volume. For
that you can visualized vertices with new "Point Density" node. Check
this part of video https://youtu.be/GhwzIQ6qZO8?t=464
If you'r looking for a way to convert your point cloud into a mesh
search for remesh  or point cloud skinning.

source: Stack Exchange

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

sort: votes


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Geometry Nodes: How to swap/change a material of a specific material slot?
I have an object with multiple materials assigned to it. I would like to use Geometry Nodes to swap a material of a specific material slot.
Example: I would like to change the material of slot 2, but keep all other existing materials.
An ideas how to do this?
Thank you!
PS: It has to work in Blender 3.0.1 if possible.

Maybe a I need to mention it has to work in Blender 3.0.1. Sorry.

You would first have to query if an existing material index has a certain value, and use this result as selection for the node Set Material:

This work great in 3.2.1. I have to look how I get this to work in Blender 3.0.1.
Before you ask, why: We are in a production and need complex tests before moving to Blender 3.2.1. Some of our existing scenes are not working in Blender 3.2.1. As long as there's no fix, we stay using Blender 3.0.1. Thank you!

@ChristophWerner According to the documentation all nodes used here should at least be available in Blender 3.0. If it still doesn't work, then once again a bug is responsible...

"Compare" isn't implemented in Blender 3.0.1 like this, yet. You can compare floats only.

@ChristophWerner Ah, yes, thank you, absolutely right, Compare is not yet available as a separate node in this version, but that can be solved with the other node as well. Well noticed!

Here's the solution for Blender 3.0.1. users.

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


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Geometry nodes: How to align all object faces to camera position?
Hi Geometry nodes friends.
I would like to seperate all faces of an existing object and then align them individually to the camera pos. Like the billboard technique you may know from game engines.
It's easy to scale all object faces individually, but I don't know how to rotate them by single.
Thank you in advance
Chris

do you want them to face the camera fully, or only around one axis?

Yes. This would be great.

btw @RobinBetts this is what it looks like:

Excellent! I was being too clunky to think of that :D If it had been in time, this should have got the tick. Maybe it still can.

Both solutions are actually right. The solution by shmuel is a bit more readable for people like me, who are "more artists than coders". But we can also learn a lot by the first solution Robin posted. Thank you both for the invested time!

@RobinBetts , the way you said is probably better

@ChristophWerner Glad you could change your decision!  Ain't that funny? The way I'm wired up, I find this way of thinking about the problem more difficult. It took me a while to figure out why it worked. For you guys, it's the other way round. :)

This group:

Finds the vector orthogonal to both the face-normal and face-to-camera vectors
Finds the angle between the latter vectors in their common plane
Rotates points about the vector found in step 1, passing through their face-centers, by the angle found in step 2.

.. with this sort of result:

... but @shumel has raised a good point in the comments.. you may want your faces to swivel about only one axis, say, (0,0,1).

Exactly. But I think I'll find the solution by myself and post it here. Thank you.

@ChristophWerner Thanks! If it was 0,0,1, you can forget the cross-product, just project both vectors onto XY  (set Z=0) and normalize, and then find the angle via the dot-product as above. I'll plug that into the answer if you like.

you could just use the align ruler to vector node instead of all that math.

@shmuel I'm always up for saving a few nodes.. could you demonstrate? (If you mean Align Rotation to Vector, you have to know what the rotation is, in the first place)

True I didn't think of that. Still, you can use two align euler to vector's; one with the normal(vector) and -1(factor) and a second one with the direction(vector).

but the way you did it might be better (under the hood). not sure

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


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How to update/overwrite surface normal data in geometry nodes?
I've an object with custom normals set. It's a source for simply instacing some objects by using geometry nodes.
As soon as I use the "Realize Instances" node to get an exportable mesh, all my custom surface normals will be reset to the regular smooth version / get lost.
Is there a way to keep my custom normals surface infos or transfer them to my Realized Instances version including all distributed instaces?
Thank you
Chris

As far as I know, custom normals aren't supported yet.

How about data transfer from instanced geometry by topo after the GN?  Should apply and export just fine.

the problem is that they are realized, so that many separate instances becomes one joined mesh. So it should be very difficult to use data transfer here...

I guess normals can be baked into texture..

The data transfer modifier works with a source mesh, where normals have to came from. I would like to keep just one mesh and don't make a copy of it. And as @Crantisz writes: You need a realize instances node to transfer all normal data to the instances.

I need a realtime solution and can't bake normals to a texture.

As currently discussed here, it is not possible to access or modify this data with Geometry Nodes.
Therefore, the problem cannot be solved currently (or in the foreseeable future).


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Star flare in Eevee?
Continuing my star flare question. I am now teaching myself Eevee and Blender 2.8. I'd like to add the star flare as seen in this screenshot to one of my sets. I want to set it to a stage light bulb. Anyone have any suggestions?
EDIT compositing seems to work but not quite as I expect. Index OB and Index MA are gone and I'm trying to assign the flare with streaks to one object or one material. Suggestions?
EDIT 2 I am so close with this! But it's hitting the neon lights, which I don't want it to do. Just the stage lights in the back. By the way, super thankful for your help! Any suggestions on separating? The neon is a different hue of blue, but it seems to hit all blues.

I think your only option will be to use the compositor to add the flare - Eevee does include Bloom settings but this is non-directional.

I have a flare node already made, but it seems like I'm having issues making it appear.

Don't forget to accept the answer of your question via the green mark on the top left corner of the answer.

AFAIK, values rendered fromm Eevee don't seem to be taken into acount when compositing. I don't know if it's a bug. But here's a work around :

Set a color for the objects you want to add streaks on. Make sure you don't use that color anywhere else in your scene. I used a full red (rgb 1:0:0)
In the compositor, we will use a Chroma Key node do create a mask out of that color. Play with the cutoff & acceptance to really isolate your lights
With Alpha Over node, we will take the original render and use the new mask as factor to put our lights on black background
Let's add a glare node. The mix value must be set to 0
Mix the glare result to the original render with 0.5 factor

It's really not the best solution but hopefully, all the render passes will be back at some point.


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Material only assigning to part of object, not all of it
EDIT: I've since discovered that the issued stemmed from the fact that the light wasn't shining on the black areas. Change it to hemi and the problem is fixed.
I'm new to blender, but I have a grasp on the basic functions. Supposedly. I've gone through an excellent course on it, but I'm still a bit lost in the area of materials and textures.
I am currently trying to texture a roof of a hut. Despite the fact that I've selected the whole roof in edit mode and assigned the material with the texture on it, only part of the roof gains the texture - the top.

Note: The top of the roof is tecturing properly: it looks solid because I'm in material view, not render. That's not the problem. The problem is that the texture is not assigning to the whole of the roof. Not the black edges of the roof, and the underside (if you open the project linked below). Those areas need to have the texture.
Why is this? I've tried to assign the material to the whole object multiple times, even selecting only one or two faces that were not affected. I can't tell if the material is ignoring the faces, the texture is, or both are (since the material looks no different from the rest of the hut for some reason - a way to tell that would be nice if I'm missing it).
I want the texture on the top of the roof like it is, but also on the sides and underside, which you cannot see in the picture. The roof is a single object, separate from the rest of the house.
File to download.
Folder to download, including texture.
What I've tried/checked:

All normals are facing the correct way. This is the first thing I checked.
I'm in Blender Render, not Cycles Render (I did some research and that was mentioned).
The material/texture does work. It's on the top of the roof, after all.
I have no way to confirm that the material is assigned to the whole object, though I don't know why it wouldn't be. I assigned it multiple times. I even deleted it and started over with the whole roof selected (ctrl+A).

Could you provide a .blend file to be able to help you?

@Tak I've edited in a link in my question.

If you have solved your question you should add an answer using the answer section below and accept your own answer, not edit your original question.

Check your UV map. I supect some of the faces are not mapped correctly.

You need to set the diffuse color as shown below for all the parts you want to have the same material. So I added new material for the other parts as well and set the diffuse color to be the same as shown below:

The updated .blend file can be found here:

I think you might have misunderstood my question. I've edited it to clarify; see the 'note.' I want the texture to be on all of the roof, including the sides and underside. Not just the top. The top already works fine if I look at it in render mode.

@ThomasMyron answer updated with screenshots and an updated .blend file. Please accept and upvote the answer if it was helpful.

I think I need to go and learn more about materials and textures. Your file has the material on all the faces, which is great, but I can't change the color (it's like the material won't re-apply), and I still can't get any kind of texture to show up anywhere. Thank you for your time; I'll edit the OP if I find out what I was doing wrong.

You need to unwrap your mesh to your texture - select all the faces in edit mode and press 'U' to unwrap, and choose your preferred method.To test, I set my view to Top from the numpad ) and used 'U, Project from View" and loaded my own image since yours wasn't packed in file.
You still need to edit your mesh to include a seam. I chose the vertex loop around the bottom edge of the roof, and then also (in edge select mode) the edges that were vertical tha tconnect the top to the bottom of the roof, and pressed ctrl-E and choose 'mark seams'. Then with all the faces selected, I pressed 'U' for unwrap and then scaled the whole island up in the UV Image Editor to set the scale for the texture against the uvs. The image texture then sits on all the faces, and since it is a tiling texture it works pretty well now.

I think you might have misunderstood my question. I've edited it to clarify; see the 'note.' I want the texture to be on all of the roof, including the sides and underside. Not just the top. The top already works fine if I look at it in render mode.

No, I just pointed out that you didn't unwrap your mesh. You will need to do that to get an image texture to map by UV as the default mapping. If you want to use generated coordinates instead, you might have a difficult time getting it to line up. Select all of the faces and Smart Unwrap and that will get you an image on all faces - but the best thing to do is to unwrap the roof from the top view, and then use the other views to unwrap the sides, etc.

Well I think one problem is that I've never come across 'unwrapping' before. I don't know what it is. I was under the impression I just assigned a material to faces, and then assigned a texture to the material. Is there another step in there?

Yes, you need to tell the mesh how to line up on that image per face, so you Unwrap it with the U key either all faces at once or sections at a time, and line them up in the UV/Image Editor to coincide with the pixels of the image texture. Procedural textures do not need the UV mapping, but images really do if they are going to be used in the viewport.

I guess I'm confused why I can see it on the top just fine then, when I'm in Render view. When I unwrap it, the picture zooms in a lot more... I liked it unzoomed. It was the perfect size.

Get a new file up with the example texture you want to use packed internally so we can see what you are seeing.

I've added a folder with the file and the texture. Hopefully it's shared correctly... It looks exactly like Tak's picture below, except it is a texture and not just a material. You can see how it isn't on the sides.

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


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How can I manually fix nonplanar geometry?
I'm going through a course on blender. The course teaches blender through the use of several projects. Right now I'm modeling a low-poly chess set, and we've arrived at the knight. Because we made the knight free-form (just extruding faces and edges up from the base), and because we want to stay as quad-based as possible (to preserve loop cuts), there are a lot of nonplanar faces.
I've modeled my knight, and would now like to fix the nonplanar quads. Most of them only need one or two vertices pushed a small distance (typically less than 0.05BU). My problem is that I can't push them the right way.
In all of the transform orientations (global, normal, gimbal, etc.) the axes never point in the exact direction I need to push the vertex. The closest I can come is the view oreintation, which isn't exact for those vertices not perpendicular/parallel to a side (front, top, right, etc.).
So how can I fix my faces? Is there a way to fix nonplanar quads? Do note that this is a low-poly model, meant to look blocky. The subdivision modifier will not be used.

Note that in the course, the instructor simply uses the edge split modifier. I don't like that, as it is not fixing the geometry, and my model still has triangulation on it (the modifier essentially does nothing). Even if it did work, I would prefer to actually fix the problem instead of pretending it's not there.
You can download the file here. Note that I am using the mirror modifier, which is why there is only half of a knight. You'll have to turn both modifiers off and turn mesh analysis on to see which faces are non-planar.

Could you add what you hope to gain from a model, which only consists of planar quads? If you are using the subdivision surface modifier, smaller quads are going to be created which are even "flatter".

https://blender.stackexchange.com/questions/56755/flat-quads-or-why-is-my-mesh-so-funky

@Leander I don't follow. The faces need to be planar so that we can control the way the knight renders. They need to be quads to preserve the loop cut capability (remember this is a course I'm taking, and not 'my decision'). I am not using the subdivision surface modifier, as the chess set is specifically following a low-poly look and feel.

You may want to use the answer here .. the custom orientation would work the same way, for flattening quads.

@RobinBetts Exactly what I was looking for. Tedious, and the nonplanar geometry spreads around as you move the vertices, but at least I can control it. Thanks!

As soon as I suggested it, I thought.. you would have to remember which verts are now in planar quads, and make sure they'e included in the basis for future corrections.. leaving open the possibility of being cornered into turning your knight into a  ball of crumpled tinfoil. Low-poly enough, and you can judge priorities. But there must be a better way...

Ah, I didn't know it was meant to be low poly.

I will compile multiple methods here from various sources.
The methods for a single face will work for multiple faces if you choose
Individual Origins as the Pivot center for rotating/scaling. However, this will only work for faces which aren't adjacent. If they share common edges, the single face options will treat them as one large face.
Scale along normal (single face)
Select the vertices of a face, choose the Normal Transform Orientation, then scale along the Normal Z axis. You can do this with the scale manipulator or by pressing SZZ. You can make a single face planar by scaling to 0 with SZZ0.

LoopTools Flatten (single face)
If not already, activate the preinstalled LoopTools Addon. Select the face and choose the Fatten operation from the LoopTools addon. It is available in the 3DView toolshelf T under tools > LoopTools or in the specials menu W > LoopTools Flatten.

Make Planar Faces (multiple faces)
From this answer, there is a tool to make faces planar.

Shift single Vertex
In this answer is a script to make a face planar by only changing a single vertex. Select the three vertices of a face, which shouldn't change, then Shift select the vertex which should be shifted, marking it as the active vertex.
Then, call the Flatten Vertex operator (see the linked answer for details).

Note, that this will not update the Mesh Analysis display. But that will update after a Zero operation, like G0.


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Create a stretchy line between two objects?
So I want to create this stretchy rope effect as seen in this video.
I want to use either soft body or cloth physics, so I can bounce objects off of them. And I also want it to be connected to two points that move around.
Theres a similar post here, but I can't get it to hook onto both objects. It will either hook onto one or the other, but not both.

I couldn't get it to work with a curve as suggested by Greg Zaal, as you said the curve doesn't seem to want to stick to multiple hooks at once..
However it works fine for me using a mesh as explained in my previous answer, and it still runs realtime at 24 fps for me:

Example .blend

I never thought of using Soft Bodies like that, good idea. I always use a curve with hooks. (It sticks to multiple hooks for me)

Ok it works great! is there a way to animate the string shorter and longer? like without it being so loose?

@DragonHeart You can increase the tension by adjusting the Pull value in soft body edges. To actually make it longer or shorter, adjust the initial mesh. You might be able to animate the length with shapekeys, but I haven't tested that yet..

Just tested it. It worked! Thanks for the big help!

@David Now I'm curious.. Can you upload a .blend?


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VSE Motion Blur?
So I'm editing a video with someone jumping really high, and I've masked them out, animated them, and it looks fine, except for the motion blur. The person I've masked out is way too crisp!

Is there any way to use Blender's motion blur settings with the vse editor?
I really don't want to use the blur effect, as it really doesn't provide the best results

i don't use the VSE but i think you should be looking for a smooth mask instead

I think this is possible in the compositor, but I'm not sure about the VSE.. See http://wiki.blender.org/index.php/Dev:Ref/Release_Notes/2.64/Mask_Editor#Compositing_Node

Okay, looking into it...

There are some VSE to Compositor solutions, try to google them.

Non linear editors are generally not used for compositing for a number of reasons. NLEs have very thin margins for performance, while compositing may require hundreds to thousands of operations to craft a desired output. In industrial imaging, these two processes are isolated and divided for this very reason.
While you might not be doing post production on a feature length film, there is much to be gained by following the patterns that such projects follow.

Cut your project into the shots and timing you require using an NLE. Once you are happy with the pacing and the edit, your edit is "Picture Locked." You now know precisely which frames you are going to be performing deeper surgery on and what elements you require.
Take your work into the compositor and perform the surgery. You gain the added quality of compositing on 32 bit float imagery as well as avoiding other not-so-obvious compositing problems such as nonlinear color blending. Specifically regarding your work, you can find various tools to help you regarding motion blurring. See Motion Blur option in the mask node.
Repeat for each shot required. At the end of the process, output your still frames and encode to a final motion picture format if needed.

Wow, thats really quite amazing! I am definetly going to try this workflow out. Thanks for the great support!

@DragonHeart While alien at first, an offline to online process will almost certainly elevate your work. It forces you to focus on particular regions of production at the proper moments. Editing during editing. Effects during effects. Grading during grading. Etc. By allocating time and energy to discrete phases, you waste less time twiddling elements that have no place. As no surprise, this pipeline has been used for nearly a century of motion picture imaging.


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How can I emit smoke from just the outline of a model?
I know my way around Blender a bit, but I'm in no way an expert. What I am trying to do is have a humanoid mesh that is invisible, but have smoke emit from it's silhouette only, not it's volume. Is there a way to generate a mesh on just the outline of a model similar to backface culling with solidify modifier so that the smoke only generates at those locations?
I tried to keep the question short, but let me know if anything is unclear.
Thanks!

making a fire creature?

Use the mesh as emitter. Use vertex painting to paint the “silhouette” as a vertex group. Set vertex group in smoke. Set volume to 0.

While not a 'true' silhouette (as it's a slice through your model, rather than its true outline), one solution is to simply use a Boolean modifier on your model with a scaled cube (scaled right down in one dimension to make it a thin slice). This will produce a thin slice of your model that you can then emit the smoke from its faces :

Add layer weight node in shader editor.
Connect the layer weight input to the factor of smoke shader


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Blender Render rendering dark, spotty and weird image
I made a whisky bottle and two glasses. My goal was to make a dark, moody scene with violet and some yellow light, but whatever I'm doing, it's wrong. The glass looks distorted and not correct, not at all realistic, not even near it (I'm using cycles) - I think you will know what I mean, when you see it.
Also, somehow I can't get it to be brighter, I have always these dark points, even though I added a sun and two area lights...

Looks like it's a problem with your world background.  Not sure if you had an HDR image in there but it wasn't packed in the blend file but I found what I believe to be the correct one from HDRHaven.
So you need to pay particular attention to the enviroment texture node.  This should be set to Mirror Ball projection with Raw color space.
Also you need to plug this into the background node, then the background into the World Output Nodes surface input.

I also suspect that your area lights have too much power, so dialling these back to results in the following rendered at 720P with a mild fog glow composite node:

Here's the updated blend file (be careful, I ramped up the Cycles resolution to a higher value, don't fry your CPU trying to render this)

Update
There was a problem with the mesh of the glasses (I'm sure I mentioned this last time). I've fixed it, shows a noticable difference.  I've also upped the lighting, but I think this is too saturated. I've updated the render and blend file.

hello merlin, you again! hehe :-) thank you for your tips!

I've updated, let me know if this is what you were looking for.


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Texture not showing up in render preview
why does my texture, that I painted in Blender, show up in "Viewport Shading" but not in "Rendered View"? Everything is just grey.
https://drive.google.com/open?id=1Fy_OFy_3RwtG8tq7dtzQ5A8-up_wJ_dp

I had a look at your scene file-
1/ You're using 'object' rather than 'UV' in the shader, so it's mapping the image incorrectly.
2/ No idea what has happened to make it invisible, but it is! However I just opened Blender into a default scene, then Appended your object and it shows up fine.
If you get into a mess, just open a default scene and append the objects/lights/whatever. It's a sort-of 'get out of jail free' card...

The OP did not ask for a critique of his/her faults in the scene, the OP asked for an answer to why the render is apparently not starting.

As can be seen below, you have accidentally paused your rendering, preventing Blender from initializing your render.

Simply unpause it by clicking on the button again. Cheers!


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Replicate value stored in object into properties of new one
I would like to duplicate, for example, a cylinder with its number of vertices stored in its properties, and tweak this value if needded.
To do this, I click on a gizmo, and a new cylinder is created, with the stored value of the previous cylinder. But when I want to change this value within the property panel, the value remains the same.
How can I change it?
Here is an example:
import bpy
from mathutils import Matrix

bpy.ops.mesh.primitive_cylinder_add(vertices = 12, enter_editmode=False, align='WORLD', location=(-2, 0, 0))
obj = bpy.context.object
obj["vertices"] = 12

class CylinderWidgetGroup(bpy.types.GizmoGroup):
    bl_idname = "OBJECT_GGT_cylinder_tweak"
    bl_label = "cylinder tweaker"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'WINDOW'
    bl_options = {'3D', 'PERSISTENT'}

    @classmethod
    def poll(cls, context):
        obj = context.object
        try:
            if "Cylinder" in obj.name:
                goodName = obj.name

            return (obj and obj.name == goodName)
        except:
            return(obj and False)

    def setup(self, context):

        obj = context.object
        mpr = self.gizmos.new("GIZMO_GT_arrow_3d")
        mpr.draw_style = 'BOX'

        self.gizmoWidget = mpr

    def refresh(self, context):
        obj = context.object
        mpr = self.gizmoWidget
        props = mpr.target_set_operator("object.cylinder_update")
        posMatrix = Matrix( ((1,0,0,obj.location.x),(0,1,0,obj.location.y),(0,0,1,obj.location.z),(0,0,0,1)) )
        mpr.matrix_basis = posMatrix

class CylinderUpdate(bpy.types.Operator):
    bl_idname = "object.cylinder_update" # has to be all lower case
    bl_label = "Cylinder Update"
    bl_options = {'REGISTER', 'UNDO'}

    vertices : bpy.props.IntProperty(name="vertices", default=5, min=3, max=100)

    def execute(self, context):
        obj = context.object
        self.vertices = obj["vertices"]
        bpy.ops.mesh.primitive_cylinder_add(vertices = obj["vertices"], enter_editmode=False, align='WORLD', location=(0, 0, 0))
        obj = context.object
        obj["vertices"] = self.vertices
        return {'FINISHED'}

bpy.utils.register_class(CylinderWidgetGroup)
bpy.utils.register_class(CylinderUpdate)

Set verts in invoke method
Set the value when the operator is invoked (run once). Give the new cylinder the operators value for self.vertices.
Demonstration of that change

    def invoke(self, context, event):
        obj = context.object
        self.vertices = obj["vertices"]
        return {'FINISHED'}

    def execute(self, context):
        bpy.ops.mesh.primitive_cylinder_add(
            vertices=self.vertices,
            align='WORLD', location=(0, 0, 0))
        obj = context.object
        obj["vertices"] = self.vertices
        return {'FINISHED'}

Some notes.
To match new cylinder transform to old would
mw = context.object.matrix_world.copy()

before new cylinder op, and assign it to new cylinder.
The poll method could be
def poll(cls, context):
    ob = context.object
    return ob and ob.name.startswith("Cylinder")

The poll method gets fired off a lot. Good practice not to use a try clause here.
The gizmo matrix basis could be
Matrix.Translation(ob.location)

However this is using local coords to make a global matrix and will result in "losing touch" with the cylinder if parenting or constraints are used to locate it.  Worth investigating using
Matrix.Translation(ob.matrix_world.to_translation())

Automatically set the custom property when cylinder added
Check out the way this answer https://blender.stackexchange.com/a/163258/15543 manipulates the newly created mesh primitive.  Recommend doing something similar here.
When the active operator is the add prim cylinder add the custom property.  In this case could poll for "vertices" in ob.keys()  (Maybe change name to cylinder_vertices)

Invoke is exactly what I need for my project, and great thanks for the other tips, batFINGER !


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Model does not move with Rig after enabling "with Automatic Weights"
I am new to Blender and have a rigged model. I used basic human rig and generated the rig and want to make the model move in Pose mode but after adding Parent >> with automatic weights in object mode and then when I go to Pose mode and try to move the rig, the model does not move. Is there a reason why the model does not move?

hello, there may be several reasons, maybe share your file so that we can test? https://pasteall.org/blend/

Is there a warning message in the status bar that reads “Bone Heat Weighting: Failed to find solution for one or more bones”? (Related if yes: https://blender.stackexchange.com/questions/15964/heat-weighting-failed-to-find-solution-for-one-or-more-bones)

There is no error that shows up.

@moonboots here is the link to the file https://drive.google.com/file/d/1xu1HstwBCSoUugO1NMQlhRbXZcbYIwU9/view?usp=sharing

@Blunder Thanks for the response but I could not see any warning message

you have 2 armatures, which is the one you want to parent to, and how are they supposed to work together?

@moonboots ok that means I need to delete the first armature, but don't know how to do it actually

I think the 2 armatures are supposed to work together but I don't know how  :/

@moonboots The first armature has the model in it and I deleted the rig that came with it and created a new rig which is the second armature named metarig.001, but need to figure out how to make both work together

do you mean the first armature was already separate? I'm not sure to understand this system, I hope someone will help

@moonboots yes the first armature was separate. Thanks for checking it.

Did you import the model from MakeHuman?  Whether you did or not, its scale is all messed up, and neither metarig really works with it.

@MartyFouts Hi, I actually got the model from BlenderMarket

Is there a reason why you want to merge the rig that came with the model with the Rigify rig? I'm just asking because this makes no sense to merge them. Either use it rig it had or use Rigify (and remove the existing one). It looks like that you deleted several bones, did you? The Armature rig only has one hand + forearm and toes everything else is missing. The mesh works with Rigify but you need to clean up the mess first ;-) Rigify has a base rig without fingers and face, and another complete rig. There are a few things to do to get it properly working (especially the eyes and fingers)

@Blunder yes. I removed the bones from the original armature it came with, but ended up leaving some of them, still learning how to remove the armature properly, I tried to delete the armature but it removes the model when I press Delete on armature, so trying to figure out how to remove all of that and then just work with the new rigify rig.

Ah ok. You don't need to delete the bones. Just clear the parent (Alt+P) of the mesh. The model does not get removed if you delete the armature or clear the parent. It just reveals the true size of the body mesh, which is 136m! Zoom out a bit or turn the viewport camera and you will see it. To use Rigify you need to scale it down, apply the scale and do a few more things for the fingers & eyes. A face rig is not needed because the model has shape keys for facial expressions. But the shader is not ideal and needs some tweaks, too.

@Blunder ok thanks for the tip. I will work on it and see what I get

I was going to post an answer but it's hard to keep it short. I try to finish it later. All in all the model works with Rigify. You can use the full human meta rig so you can use the jaw controller to open her mouth. https://imgur.com/a/JM0KlR0 I can upload the file if you need it for reference.

@Blunder yes, sure that will be great if you could upload the file. Thanks


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I accidentally deleted my video proxy file and now the preview wont show for that clip
so I was editing my video and everything was going smoothly until I noticed a file that said BL-proxy or something like that. I had no clue what it was for so I deleted it and continued editing my video. I closed Blender when I was done for the day. The next day I opened it and the intro to my video was there, but the main clip wasn't. It just showed a blank screen and all I had done was delete that proxy file and make the shortened clips into a meta strip then edited some more and made those another 1 meta strip. I tried unmetaing them but didn't work. I don't know what to do and I couldn't find the original clip I had as I could only bring back a copy. Please help me not lose 7 hours of work.

If you're on blender 2.93+ and have auto proxies on then select all strips and in the Preview sidebar switch from the current proxy setting to something else and back. Then it should start rendering. If not then select your strips then in the Preview View menu, select Proxy > Setup, choose the resolution, then Proxy > Rebuild and then it should render, then ensure that the preview has the proxy % you rendered the proxy files to.


text:
Watercolour shader
I am trying to achieve a watercolour effect based on a reference drawing that I've seen.
I am trying to make a shader that blends colour like watercolours blend on the paper.
I am attaching the reference drawing. The drawings are sections, but I would like to achieve similar blends between 3d objects when rendering.
Does anyone know how to go about it?
My initial thoughts are somehow inputting an object's colour into the colour ramp of other objects...somehow!

Have a look at This Tutorial

Hi Marty! Thanks for your reply. that's a really good tutorial. The main issue I want to solve is shaders on different objects blending their colours based on the view.  Although the water colour texture is spot on, the shader is doesn't take into account other objects in the scene. .


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Strange shadows in Eevee orthographic camera
If I use Cicles engine everything looks great (obviously). I try Eevee engine with perspective camera mode, and result also fine. But I need ortho projection. If I switch to Eevee + orthographical camera the shadows are absolutely terrible, here you can see.

I use (and need) Sun-light, and try increase Shadows Cascade Size to max value 4096, and result is still awfull:

Any ideas how to fix it?
Blender 2.93.3
Many thanks for any help.

The official Blender manual knows everything, lol. If you have the same problem you need to decrease the Clip End value for your orthographic camera. Its all because of the way Sun-light Cascading Shadows work. My default Clip End value was 1000, too big. With the 200 value the shadow rendering started to look fine.


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How to add and update mesh in blender python game engine
I am trying to build a simple game in blender, however, I have run into a problem. Here is an example of what I am trying to do.
import bpy
import bmesh
bpy.ops.mesh.primitive_cube_add(enter_editmode=True)
mesh = bpy.data.objects['Cube.001']
me = mesh.data
bm = bmesh.from_edit_mesh(me)
bm.faces.ensure_lookup_table()
for x in bm.faces:
    x.select = False
face = bm.faces[3]
face.select = True
print(face)
bpy.ops.mesh.delete(type='ONLY_FACE')
bpy.ops.object.editmode_toggle()

Cube.001 never gets shown until after the game exits back to the editor. Thanks in advance!

For the discontinued BGE in previous version of Blender (< v2.80), the BPY API is not associated with the BGE API. Any manipulation of mesh data has to be done through the use of methods and properties provided in BGE classes like bge.types.KX_MeshProxy, bge.types.KX_PolyProxy, andbge.types.KX_VertexProxy.
You cannot change the topology of a mesh at runtime, meaning that deletion, modification, or creation of face, edges, or vertices are not supported outside changing simple attributes like position. You will either have to implement a workaround, recompile Blender with that functionality, or switch to something like UPBGE that allows for use of the BPY API at runtime.

Hello and welcome to BlenderStackExchange,
For me using the latest UPBGE 0.3 release I oddly get the opposite problem;
Cube.001 is disappearing after runtime because Blender is automatically deleting as it wasn't originally created in Blender's viewport.
For me, unselecting the Undo at Exit setting prevented Blender from removing the newly created object after runtime had exited solved my issue, perhaps it'll work for you as well.

Also, the reason your newly created mesh may not show for you at runtime may be because you need to convert your mesh to a BGE object. Dynamically created objects are only Blender objects. You can convert Blender objects to BGE objects with the following Python function:
KX_Scene.convertBlenderObject(object)

OK first, thanks for replying.  Now I dont know how to get to the window your snapshot shows and I cant for the life of me figure out what module I need to import to use KX_Scene.  Any help would be greatly appreciated.

btw Im using blender 2.79

BPY doesn't work in legacy versions (e.g 2.7x) at runtime.
Only UPBGE 0.3 allows it to work properly at runtime.


text:
How to Mirror an object and keeping the Scale to 1 and not -1
Let's assume I have a face (object) of a man drawn in Blender.
Now I would like to mirror the face, but not by changing the scale of 1 to -1 or from -1 to 1.

hello, in what way is it a problem to use a scale of 1 to -1? Also, are you talking about Grease Pencil?

you can use Ctrl M, Symmetrize, or Mirror modifier for example

I am trying to export an aircraft model for use in MicroSoft Flight SImulator 2020. MSFS produces errors if the scale is neagtive. "Node 'node26' has negative scale, ignoring negative sign." The result is that parts, connected to node26, are flying around the model in the Simulator.

I'm not sure what it means, one thing you need to do though is recalculate the normals once you've mirrored with SX-1


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Blender Spreadsheet Not Generating Data in Geometry Node
I am creating a basic geometry node and it was first creating the x,y,z values of the Line in the spreadsheet as show below.

However, when I pointed the geometry node to a Point instance the x, y, z values are disappearing.. why is this so?

I got it.. instead of selecting the line i should be selecting the main object of my point instance which was the circle on top


text:
Creating 3D Blender Objects using the Fibonacci Sequence or Math
I would like to create objects using the fibonacci sequence. such as the following:

I have checked online and saw this add-on https://blendermarket.com/products/fibonarray
It seems kinda outdated and i am not sure if they work for MAC OS. is there anyone who can refer me to an add on that is updated or a blender file that I can start with? Much appreciated.

There are quite a few posts about this subject, but a bit of reading is involved there are multiple techniques. Maybe start here:
https://blender.stackexchange.com/questions/1371/organic-yet-accurate-modeling-with-the-golden-spiral/1376#1376

Check this Geometry nodes demo https://download.blender.org/demo/geometry-nodes/erindale_still-life_geometry-nodes_demo.blend

IMO Fib is always an interesting subject, & despite closing as dupe would really like to see any new methods to create fractals. Consider adding a bounty to fractals question linked, or an answer using demo linked..

@Crantisz wow thanks for this! do you have documentation for this? seems quite complicated

@batFINGER this group likes to close the questions fast disappointingly

Search for geometry nodes.


text:
Select Upper 4 Edges of a UV Sphere
I would like to select the upper 4 edges of a UV sphere as shown below.. what are the steps to make this happen using a MAC IOS Blender


text:
Blender 2.71 parenting objects transforms objects
Whenever I parent an object it gets distorted or transformed in some form or fashion when I press "P" in game mode...is there a way to fix this?
See the top picture shows what it supposed to look like...then I press "P" in game mode and we jump to the picture below and objects go megatron on me and are transformed.

A general advice is to have no scale on your objects if you do not need it. One thing you really need to avoid is in-homogeneous scaling (the axis get different scales).

Apply the scale of the parent objects into the mesh via ctr+a + Scale

Thanks that did it!
Lol...already got a work around and ditched the parenting all together but will have to keep that in mind for future reference.

Typically the scaling does not change when entering the game engine. This is different, when you are playing an animation or change something via Python.
My advice to you is to void scaling (especially the in-homogeneousscaling) at the parents.
If you need scaled meshes, you can create the object tree by using empties as parent. You can parent the previous parent objects to the empties. This way they are no parents anymore and you can scale them without side effects. Just make sure the empties are not scaled.
Example:
Frame (scaled)
- Button A (scaled)
- Button B (scaled)

changed to:
Root (Unscaled Empty)
- Frame (scaled)
- Button A (scaled)
- Button B (scaled)

or
Root (Unscaled Empty)
- Frame (scaled)
- Button Base (Unscaled Empty)
  - Button A (scaled)
  - Button B (scaled)

I don't want anything scaled though.
All I want is for the mesh to stay the same as shown in image 1 (top) but once I parent an object(s) to another object and press "P" in game mode it transforms the object as shown in image 2 (bottom).
I have no type of scaling animation or coding in the file nor do I want anything to be scaled.

In that case I suggest to apply the scale of the objects into the mesh via <ctr+a> + Scale.

added the file so you can probably see what I'm talking about...all you need to do is press "p" in game mode

I do not see any unwanted scales. In my version (2.74) the preview matches the in-game look. I tested in 2.76 - it does not apply unwanted scale either.

I see in your file the objects are not parented together. Is that a solution?

I went ahead and did a work around and removed the parents and it stopped the scaling in the preview.
But if I were to parent the object(s) and then do preview, they'll get transformed in some way

As said: unsure there is no scaling at the parents, either by converting them into mesh scale or by using other un-scaled parents. Both solutions worked on your file.


text:
Where to set 'use_blender_profile' option?
I have seen that the Collada exporter uses a flag called use_blender_profile.
Looking at the source file, it seems that this option allows to export additional information in the Collada file :

connect to say if the bone is connected to its parent
tip_x, tip_y, tip_z to tell the length of the leaf bones

Without these values, the information is lost as Collada encodes the armature differently.
But where and how use_blender_profile can be set ?
Am I right about the exporter behavior ?
The blend file :

I would report that as a bug. The code appears to be there and there is no conditions to show/hide it. It is listed in the rna/dna files and it's in the operator and layout functions with the other options that are visible. I don't see any reason the option should not be available during export.

@sambler thanks, have a look from the line 177 of ArmatureExporter.cpp (current version). How to report that ?

That's where the option actually changes the exported data. The problem is earlier in that the option is not made available to be turned on/off. You report the bug at developer.blender.org, you can simply write file xx/yyy/this.c or you can add links in the bug report the same as here using [text](link/to/file$linenumber) adding $177 to the end of the url will reference a specific line.

OK... first time I do that, but done : https://developer.blender.org/T48801?workflow=create. Thanks @sambler

You find the setting in the exporter's option pannel:

Note that this is a new option (added in june 2016). This option will become available in Blender 2.7.8. Of course you can download the most recent nightly build. There you should find this option as well.


text:
How to get keyframes and related information?
I'm a bit (or more...) lost about keyframes and fcurves information even if I have read this question and answers or others and tried to understand the related documentation.
What I'm trying to do is the following:

Looping along frames which have keyframes set on them (only these frames)
For each keyframe retrieve the related keyed objects (I'm interested in objects and bones only) and retrieve the keyframe information (location, rotation or scale only)

How to do that in Python?

I think it's something like that :
import bpy

for ob in bpy.context.scene.objects :
    if ob.type in ['MESH','ARMATURE'] and ob.animation_data:
        for fc in ob.animation_data.action.fcurves :
            if fc.data_path.endswith(('location','rotation_euler','rotation_quaternion','scale')):
                for key in fc.keyframe_points :
                    print('frame:',key.co[0],'value:',key.co[1])

Keyframe in blender are not store in one place. It's store on action related to object. You can look throw all keyframe on your blend file in bpy.data.actions. To filter by object type you have to look throw objects in your scene and find the related action

I think it would be useful to add some explanation alongside the code to explain the methodology.

@RayMairlot, I agree. I get the way the code is. My problems are more about the data itself. For example, what contains key.co exactly (the doc is lean about all that). And, do these key.co contain only the keyframes visible in the timeline?

key.co return a tupple with the first element is the frame and the second is the value

So key.co[1] is a weighting (because value is very broad)? I will accept your answer as it gives me a great help. But the really hard thing (to me) learning all these is about the meaning of what is accessible...

Related http://blender.stackexchange.com/questions/27889/how-to-find-number-of-animated-frames-in-a-scene-via-python/27946#27946

key.co[1] give you the value of rotation in radians. In python you have acces to pretty much everything in blender but it's something hard to find the simplest way


text:
Damped track : is this behavior expected?
A camera following a nurbs path and a damped track constraint :

At several locations of the curve, the camera rotates curiously.

But the tool tip of the constaint indicates "points toward a target performing the smallest rotation necessary".
Is the behavior shown in the gif above expected ?

I think the problem is that this constraint only rotates a single axis https://vimeo.com/171278084#t=24s

The erratic motion appears to actually be due to the Path Animation 'Follow' setting - it seems to be interfering with the constraint. When the Follow setting is disabled the erratic motion no longer occurs and it snaps back to the rotation based only on the constraint.

The Damped Track constraint isn't really ideal for camera tracking - best to use the Track To since that is capable of maintaining the expected orientation of the camera (ie, so 'up' points towards the global 'up'). I believe Damped Track is better suited to bone or object rotations where it perhaps makes more sense (but only if the 'initial' rotation is not being modified before the constraint is evaluated).

I think I've seen similar in different situations.
If so, the problem should dissapear if you separate the camera and the tracked point in for example Z-direction. I have not proof but it could have something to do with precision and the floating point math.
Also...
Have you tried to constrain the rotation of the camera using lock_rotation?


text:
Modal operator and opengl drawing update issue
For this question, I've coded a little script that draws mesh's elements indices with opengl.
All is working well, except when in edit mode, some grab, scale, rotate is done. In these cases the drawing needs to come back to object mode to work properly:

How can this be fixed? (I don't want the drawing to follow at runtime the transformation, but at least find a way to update it when the transformation is validated)

I'm interested in the answer, too.


text:
rigid body on windscreen of a car
I have a jeep, and I want the windscreen of the jeep to bounce up and down because of the movement of the car between these two positions by using rigid body physics:

I tried using the hinge rigid body constraint, which works perfectly fine to let the windscreen drop down by gravity, but when I try to move the jeep the windscreen doesn't come with it, like it isn't parented anymore. When I select animated in the rigid body physics tab, the windscreen moves with the jeep, but the rigid body physics don't work.
How can I set up the rigid body physics so that the windscreen bounces up and down, but is still parented to the car?

It could work in a way like this (see the example .blend in the linked zip file below):

add an empty with the Z (mandatory!) axis along the axis of rotation you expect for the windscreen
add a (physics) "rigid body" passive setting for the body of the car (or whatever should "hold" the windscreen), set it to "animated"
add a (physics) "rigid body" active setting for the windscreen
set a (physics) "rigid body constraint" setting for the empty and set the windscreen as object 1 and the "body" (or whatever) as object 2
set Z axis limits for this constraint ( I used -5°/+80°)
select windscreen, then the "body" (or whatever) and CTRL-P to parent the them. Do the same with the empty.

now, if the car is animated and then stops, the windscreen behaves similarly to what you expect. You may have to adjust settings, damping, friction, etc.
to see my example, open the .blend in this .zip, and press ALT-A to start the animation: http://amrc.altervista.org/wp-content/uploads/2015/10/rigid.blend_.zip

Thank you! Changing the rigid body settings of the "body" from passive to active animated worked.


text:
Geometry nodes: How to transfer material information from mesh to the result automatically?
I've a geometry nodes tree that creates pipes from mesh edges.
To do this I convert the edges to curves and convert them to a pipe by using the curve to mesh node. Additionally I have a fillet function added.
My problem: The source mesh (edges) have already a material assigned. I would like to keep this material and set it to the gn result automatically. But in my example the result looses the existing material and keeps white. How to transfer the material information from the origin edges to the new pipe object without forcing the user to assign it manually?
My tree:

...possible duplicate of https://blender.stackexchange.com/questions/279136/geonodes-how-to-use-material-index/

The first problem is materials can not be assigned to edges. They are per face property, not edges. Edges cannot store information about materials.
But even if you have faces instead of edges, conversion to curve removes material slots, so materials will be lost. But you can use a walkaround like this to get back material slots:

It basically merges geometry with one that have material slots and then delete geometry that we don't need. If you don't have faces, like in your example, you will be able to restore material slots, but not the exact slot that you want to apply (by default it will be the first)

Great. This is exactly what I was looking for. Thank you a lot!


text:
Geometry nodes: How to rotate instances while they are moving along surface normals?
In this example the cylinders are moving along the surface normals.
How to rotate them around their local origin, while they are moving away / changing their position?
Just rotating the instances is not working right. See Rotate Instances Node.
What's wrong here?
It have to work inside the simulation, please.

I've got a solution by a friend of mine and would like to share it with you.
Sometimes you get into a "nodes tunnel" when trying to achieve something new...
I completely overlooked that it's also possible to provide dynamic values outside a loop.

Indeed. Remember everything before a Simulation Zone is locked at frame 1 and never use again. Instead it uses the output of the zone from last frame.


text:
Geometry nodes: How to keep/combine vertex groups that came from instances?
Do you know how to transfer/combine vertex group attributes from collection instances to the final geometry nodes model? I need them as vertex informations for other modifiers or objects. In this case I need the vertex group center as a position attribute for an empty object.
Here's the Blend file:

Someone knows a solution?

I think your problem comes down to the vertex group being converted to an attribute. You can convert it back to a vertex group using this trick: https://blender.stackexchange.com/a/275405/60486

Thank you. But this was not the solution or I've made something wrong. Added my scene to my question if someone like to test it.

This setup works for me. The Vertex Group "Group" is transferred to the output mesh as an attribute. However, it's not converted to Vertex Group information in the output mesh. It remains an attribute.

I tried figuring this out but I think there are several problems here:

You can not change an object's location from GN => you can't move the Empty (or any other object) from within GN
To move the empty you will need a Copy Location constraint on it and that constraint would actually support a Vertex Group (VG)
BUT you can't set/fill a VG from GN and if I understand this correctly, that will also never be possible (see https://blender.community/c/rightclickselect/79gG) They write that the old and slow VGs are not good for pushing data through the modifier stack and GN will therefore not support VG outputs but it seems they forgot to consider constraints which do use VGs?

Hi ChrisP. Thank you for the infos.
About point 1: You can move empties via geometry nodes. Set Position works and Transform also. You've to use the Object Info node for this and set the "As Instance" option, inside a geometry.  But GNs can't be added to empties themself.

Christoph,
ad Empty As Instance: But you are not moving the actual empty this way. Correct?
So you can't really do anything with it outside of the GN-tree.

Exactly... useless. Unfortunately. :(

The only way to move an empty to a vertex position of an extenal mesh is to use object info and add a group to the gn source mesh by using the same name like the one in the external model. Then the empty can be moved by a copy location constraint. But this don't work with collection content.


text:
How to create a partially deformed cable?
John Dickinson asked on Twitter how to create a deformed cable parametrically, as possible.
Here's the origin post:
https://twitter.com/Motionworks/status/1564762544547692544

Below is my solution how you can solve this.

Blender Stack Exchange is a platform to help Blender users finding solutions for problems. As you maybe know, there is also a mode to answer own questions directly. But you're right, I forgot to place the actual user question. I've corrected this in my origin post above.

I've used a simple cylinder for the example.
The cable object has some modifiers to create the effect.
The bending in the cable is based on a curve.
You can download the file to see, how I've done it.
Of course there're more solutions and some are more flexible, but my example can be a good solution for the most cases.
Shot:

File:

I've uploaded 3.2.1 blend files before and tried it now - they are uploaded. I opened your file and saved it again, but it didn't work. Must be something with your file...?

Checked your file in a text editor against two of my files... my first starts with BLENDER-v302RENDH   pÀŸ¹V, the second with BLENDER-v302RENDH   Ð¹? (notice the Blender version information at the beginning). But yours starts with (µ/ý ô =› êÏ¸-RpÕ and looks completely different overall. Something wrong with this file or your Blender?

I've found the reason. My file was set to "compressed". Blender saved it compressed. This seem to be a limitation for Blend-Exchange.

Ah, good to know. I was already wondering why my very simple file was four times larger than yours.


text:
animation nodes can`t work with object that has a modifiers?
animation nodes can`t work with object that has a modifiers?
create spline from object node and use spline that has a shrink wrap modifief and subdivision modifier and I get a target curve object output that cant recognized modifiers on based curve.

AN can use modifiers with Mesh input or BMesh from Object nodes. You can create new spline from mesh input with applied modifiers.

As Serge commented totally right, animation nodes will take the modifiers into account if you use "Mesh Object Input" and if you check "use modifiers".


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Does anyone know why my bone name won't show up in the bone tab for the target when doing constraints?
I'm trying to make an IK bone, but it won't show up in the constraints tab, I press the target and go to the armature, then I press the bone tab and the name won't show up, does that for the rest of my bones now too. Any thoughts? Thanks.

hello, maybe share the armature? https://blend-exchange.giantcowfilms.com/

Two ipothesis: 1 you didn't choose the right armature, in which the bones are. 2 there are some letters in the search area, so the tab is showing only bones that have thoose letters in their name (maybe none).

Thanks for the replies. I meant to comment and say I figured it out, and it was just as you said, Josh the armature was named different. But now, I made an IK foot book and it moves the entire body while bending the foot. Anyone have any idea's why this is happening?


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I made an IK foot bone and it moves the entire body while bending the foot. Anyone have any idea's why this is happening?
Here's the file if anyone needs it so they can help figure out the problem, thanks.

You need to reduce the Chain Length to 2, so that only this bone and the thigh move, otherwise the IK also makes the Lower_Body bone move, and therefore the whole armature.

Thanks that fixed it, but now it's leaving a bit of the foot of the mesh behind. The heel.


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Targeted bones don't move with the rest of the armature
IK bones don't move with the rest of the armature
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Whenever I move the main controller bone of the mesh, most of the armature moves except for the bones the IK is targeted at, and the hand bones won't move with the armature either. Like this:

If someone knows how to fix this I would love the help, thanks. Here's my blend file:

You need to parent (Keep Offset mode) all the IK controllers and targets to the root bone.

That worked. Thank you.


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Why does Blender shut off when running a smoke simulation?
So I've decided to test run Blender. Usually I run Cinema 4D on my MS Studio here at work with no issues since it's never anything too demanding. I've found that if I run any kind of simulation Blender just shuts off. For example if I run even a simple smoke sim and preview in cycles, it's over..Blender just shuts off. Is this a hardware limitation? I never had issues with Cinema4D, Max, etc. Any help would be appreciated since I'd really like this option to work for us.

Hi. Can you explain what you mean by 'shuts off'? Blender instantly closes or does it become frozen? And when you say you "run even a simple smoke sim and preview in Cycles" do you mean you have baked (calculated/simmed) the simulation and then are trying to preview it, which is when it crashes, or that you are baking while trying to preview and it crashes? Any additional information you have can be added by using the [edit] button under the question.

Instant close is what I'm experiencing. I have no issues with baking the animation at all, since like I said I'm not really changing much other than putting in some wind and turbulence. Once the bake is done and I try to preview in cycles Blender just instantly closes. Like I said, I'm totally new to Blender so I'm just seeing what it can do. This is really the only issue I've had with it to be honest.

Ok, just trying to narrow down the actual issue. In your question you say the crash happens when you "run any kind of simulation" and also (?) when you "run even a simple smoke sim and preview in Cycles"? So is it when you change to rendered mode it crashes, when you bake the simulation or when you play back the simulation? Are you trying to play the smoke sim while previewing in Cycles or are you just trying to view a single frame?


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Timeline cursor
I'm new to blender trying to learn the viewport and the hotkeys. Every time I press the spacebar the timeline cursor starts to move obviously. A lot of hotkeys are linked to the spacebar. How do I get the timeline cursor not to start but still have the spacebar as a hotkey for the play button when I need to use the animation.

Go to page 4 in scrapbook link here. There, you will find what I consider the best playlists of 2.8x tutorials for absolute beginners like yourself. https://docs.google.com/presentation/d/13UpIjJEE7Oa7x5BiMsjXGW5CGOTDF03-SocRYi4Babs

Hi. What do you mean "A lot of hotkeys are linked to the spacebar"? Also, please make the title of the question specific to what you're asking and not just the general topic.

It was a silly question. Coming from another program I was pressing the spacebar inadvertently and obviously the timeline cursor was starting to move. No, spacebar is not linked as a hotkey to other commands, but the play/start one in timeline. Hopefully other starters who run into the same problem read this and control their thumb :-) Old habits die hard. Thank you for taking the time to answer me.


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How do I get a camera to rotate instead of rotating the object in viewport
New to blender coming from c4d. I need to set a camera to rotate around the object and at any time I would like to render the image or even to press 0 on my numpad the image it's exactly the one I have in my viewport. How do I do this in blender?

to rotate around the object is a bit too vague, do you need your camera to follow a circle shape around the object, do you need an animation, etc? Please give some details

There's a few different ways to do this but I prefer the following method.
Add an empty at the center of your target object.
Set up your camera at the desired distance from the object.
Parent your camera to empty by selecting the camera first then shift-selecting the empty.  Press Ctrl + P create the parent relationship.
Now anything you do to the empty, will by inheritance also happen to the camera.
Now you can simply rotate the empty (you can also animate this easily) and your camera will maintain the distance at which it was parented making it orbit.
The easiest way to animate this is to double click the Z rotation of the empty and enter:
#frame/31.415926535
This will create a driver that rotates the empty at a rate of 1 revolution  per 200 frames.  You can tweak this after, but you only need to use the # symbol the first time to tell blender that you want to use a driver.

You can set the behavior of the viewport to 'Orbit around Selected' in Edit > Preferences > Navigation.
You can center on selected in the viewport by hitting Numpad..
You can make the active camera adopt the viewport view by hitting CtrlAltNumpad0
These could add up to the sort of interacion you're looking for?


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Can I use my two PC on my own network to Farm Render in Blender?
Is it possible to use Cycles engine to render only GPU based from two computers in Blender in my own network at home? TY.

Yes. This is possible.

This video explains distributed rendering with Blender.
DIY Renderfarm Building Tutorial for Distributed Blender Rendering

I was trying to find out if two computers in the same network could render in Cycles the same frame or only one instance using GPU Computed feature, and not an animation or several frames. In other words the GPUs to pick up tiles of the same frame. So far I noticed it's possible the computers to pick up different frames if it's an animation going, but not same frame.  Thank you.


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How to solve z fighting and transparency? (Cycles)
The same as this question probably.
Here is the setting:

Two cubes which overlap (so, I know, they are "z fighting")
One cube with diffuse
The second with transparency

I was expecting the transparency won't be mixed here, but to see only the blue cube, because a transparent object should stay transparent (?).
Is it possible to avoid that without changing the cubes' positions?

No I don't think it is, the solution is really not to have overlapping geometry, no render engine likes that really, and most deal with it pretty badly as far as I know, unless both objects have exactly the same material. Why would you want overlapping geometry in the first place, if I may ask?

Thanks for this comment, @DuarteFarrajotaRamos, I don't want overlapping geometry, but I'd like 'overlapping geometry safe' solution for this issue.

Only workaround I really know is that if both objects use a similar shader or material color the Z Fighting becomes less visible or unnoticeable

@DuarteFarrajotaRamos, could you elaborate more this last comment? FYI, each cube here has its own material... so how can be understood 'similar shader'?

Nothing too elaborate, just mentioning that if both cubes were blue colored then you can't really see the Z fighting between them.

@DuarteFarrajotaRamos, sorry but I don't understand your comment. One cube is transparent (transparent shader), the other one is blue (diffuse shader). Could you explain what you meant?

If both cubes were to use the Blue material, instead of one being blue and one being transparent then you would never see any Z fighting, but of course it might defeat the purpose because both become actually visible.


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Why are sky textures not showing up?
I'm a Blender noob and trying to do something I thought would be simple, but is causing me grief. I'm trying to add a sky outside the windows of the classroom scene found in this Blender file I found online.
I've tried the tutorials here and here, and neither of them show any alterations to the scene when I go through the steps. It's like something in the setup of the file is overriding what I'm trying to accomplish.
I have no idea what's going on, or how to even find what settings to tweak, turn on/off etc. Any guidance would be wonderful.

This appears to be due to a several things:

Transparent is enabled in Render settings > Film.
This renders the image with alpha transparency instead of sky. Useful for compositing, but hides the sky texture (at least in viewport render).
Ray visibilities are disabled on the world material.
The compositing setup doesn't take into account the sky texture. This is understandable, as a real-life camera would over-expose the sky when taking a picture with a reasonably exposed interior.

So to make this work, you'll need to modify the compositing setup.

Start by adding your sky texture to the world material. Ensure the strength is set correctly and at least Camera ray visibility is enabled:

Disabling Properties > Render > Film > Transparent won't work in this particular case, since the compositing setup uses it create glare from the sky. Instead you can use the Environment pass:

Enable the environment pass in Properties > Renderlayers > Passes:

Connect the environment pass output of the _mainScene Render layers node to the Alpha over node in the COLOR CORRECTION frame:

You may have to reduce the amount of glare by reducing the Fac value of this mix node:

Render:


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Global variable visibility during script/operator execution?
I wanted to have some global variables in an addon.
But doing so, some parts of the script were not able to access these variables. I had an error message saying I can not use them as they are not initialized.
In this addon, I took some parts of code I have found here, in order to draw on the 3D View. The draw callback of the 'DrawingClass' in this code is able to see these global variables.
But in the operator itself, it does not work.
I have found a workaround setting these variables as class variable of the operator. So... 'it works' (even if the code is not very nice, currently).
But why some execution contexts (the drawing callback) allow to use these globals and not some others (invoke or execute of an operator) ?
I don't put the code directly here, as it is a bit long. But here is the blend file :

The variables are "inactive" and "replaceMode" which can be found in the "grsOperator" class. The script simply replaces the G, R, S keys standard behavior by the corresponding manipulator. On the bottom left of the 3D view, you can click on a square in order to change the mode ("replaceMode") or disable the key interception ("inactive").

is there a reason why you want to use global variables? i'm only asking because scene properties for instance would allow for similar functionality, and in addition get saved with the blend file

@aliasguru, just because this tool options are not related to any object or scene. Yes I should use properties, and probably I should restructure the code in order to put the drawing callback inside the operator (or something like that). But why the variable accessibility changes ?

Declaring them as globals, eg global inactive will fix the not initialized error. Check out http://blender.stackexchange.com/a/41329/15543

@batFINGER, if I declare 'global inactive = False', syntax error. If I declare 'global inactive' then 'inactive = False', I still have the problem 'referenced before assignment'

@batFINGER, ok forget it.. I read some Python docs and now I understand what you meant. Thanks !

@batFINGER, any idea about the "why" (during the callback, global no needed but during the operator execution global is needed) ?

Possibly (not great at explaining this stuff) because of registration to bpy.types.   Maybe setting up a data or settings module for your globals could be the way to go.


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Scaling, mirroring, how does it really work?
I don't really understand this behavior :
All is done in object mode.
Here are 6 identical shapes, from top to bottom rotated around the Y axis, respectively 0, -45, -90, -135, -180 and -225°.
Now I scale them -1 with 3D cursor as pivot and along the X axis (shapes on the right are 'witness') :

Now, the scaled shapes, from top to bottom (all kept their original rotation around Y) :

1 : scale X = -1, effectively mirrored (like from a mirror)
2 : scale X = -1, but not mirrored ?
3 : scale Z = -1, and appears mirrored
4 : scales X and Z = -1, not mirrored ?
5 : scale X = -1, mirrored
6 : scale X = -1, not mirrored ?

Why all that ?
Note : I don't want to obtain any particular result here (I know how to correct things if needed), but I just want to understand why it works like that.

FYI, related to this https://developer.blender.org/T42834. Indicated as "this can be closed as a known limit." by Campbell Barton

This matter because you don't apply rotation to original objects.
"CTRL+A - rotation" should solve this.

Thanks, but this is not the point, for me : the question is "why" (as I told in the note at the end of the question, I know how to obtain what I want in that matter). But I am questioning here to understand why these results are so counter intuitive.


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Too many Mesh and Verticals
i'm new to Blender so this might be a very dumb question... Still learning! So i made this frog with a tutorial on YT but the woman said to delete the modifiers after saving them but now i'm stuck with WAY to many lines... How do I undo this??

You should always keep a version with unapplied Subdivision Surface modifier. That said, you can try some things like select all and Ctrl E > Un-Subdivide

Thank you so much it worked!!

Blender creates a backup of the last save. It's called *.blend1. Maybe you're lucky and can restore a version before you applied the modifier? It also saves every 5 min the file in the temp folder. You can restore it with File > Recover > Auto Save ....

You should always keep a version with unapplied Subdivision Surface modifier. That said, you can try some things like select all in Edit mode and CtrlE > Un-Subdivide (and tweak the parameters in the Operator box).


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Taper Mesh Deform with Geometry Nodes
Hi there first post here. I am trying to achieve the effect of the Simple Deform Modifier set to Taper within Geometry Nodes. Using Blender 3.1.0

The picture to the left is my Geometry Nodes object - just a simple scattering of cylinders on a plane. To the right is the same object with a Simple Deform Modifier after the GeoNodes mod set to taper along the Z axis.
I would prefer to be able to do the same thing within the Geometry Node tree without using the deform modifier.
The main reason being that for the modifier to work I have to realize the instances, which I'd rather not do so I can use the instance objects' local texture coordinates for shading.
Surprisingliy I did not find many resources online on how to deform a mesh in GeoNodes. Any help and pointers are appreciated. Thanks in advance.

You should multiply X and Y position by Z position:

Instances should be realized before scaling.

@Gorgious Of course.

Amazing, thank you. That's good to know.
Sadly this solution still needs the Realize Instances node, which I was hoping to avoid. But it seems that I just have to realize the instances in order to be able to deform them (which kind of makes sense), so I guess I'll have to work around the coordinate issue in the shader.
Still, nice to have this solution which I find more elegant than the modifier stack. And it also helped me to better understand the concept behind instances and meshes in GeoNodes. So thank you again.


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How do I fix bone orientation or align bones to global orientation?
So I imported an XPS model into Blender and the bones of the rig are all over the place, the face rig bones seem like they point along the normals of the mesh.

I want to make some custom controllers to make animation easier but the orientation of the bones is different from the global orientation.

So when I put a bone constraint on it to follow the controllers location transformation it moves along its own axis instead of the controllers or global axis.
What I'm looking for is a way to fix it so that the bone moves along the global axis, so I'll have to either change the bones' orientation without changing the bone (if that's even possible) or I need to align the bones' heads and tails with the global axis. Would also be cool if there was a way to do this quickly for multiple bones as there are a lot in this rig.
Any advice would be very much appreciated!

When retargeting rigs, often a layer of Empty objects is used to translate between the different alignments of the control and deformation bones. For example, if the control bone is aligned horizontally but the deformation bone is aligned vertically then add an Empty, rotate it by 90°, and create a parent-child hierarchy like this control bone -> Empty -> deform bone. The deformation bone is not really a child of the Empty but copies its transformation by a bone constraint. An Empty can be a child of a bone (Pose mode). With so many bones a script would be helpful to create the Empties.

@Blunder Hm I'm not sure what you mean, I tried parenting a bone to an Empty but it didn't work, can't find the Control Bone option. What menu is that located in? Or does it have to be a special sort of empty that's part of the rig somehow? Is there maybe a tutorial you could recommend that shows this? Thx for your help.

Found a solution to this problem: I made a new bone without any weight and with normal axis orientation and then parented the existing bones to that so now I can use it as a controller to move the existing bones along the normal axes. Alternatively you can also make a new bone and then give the Child of bone constraint to the existing bones to let the new bone control them.


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Should I enable both my CPU and GPU in the CUDA preferences?
I am using blender 2.8 on windows 10. I have a question about System CUDA options. There are two checkboxes one for my graphics card GeForce GTX 2060 and another option for Intel Core i7-4790 CPU @ 3.60 GHz. Should I check both boxes? Also I have no open CL option?

I understand the need to mark opinion-based questions, but Robert's answer seems very fact-based to me :).

It depends if you want to use only your GPU for rendering or GPU + CPU. You will have to test what gives you a better rendering performance. Using a fast GPU with a slow CPU may result in longer render times than using the GPU alone, while a combination with fast CPU may improve the performance.
Currently you shouldn't use GPU + CPU rendering if you're rendering a scene with volumetrics in Cycles, because the CPU implementation of Cycles uses equi-angular sampling and the GPU implementation doesn't. This could result in visible tiling in the render with more noise being present in the GPU tiles.
The OpenCL options are only for AMD graphics cards in Blender. This may be a bit confusing since OpenCL isn't only for AMD products, but Cycles uses CUDA for Nvidia graphics cards, hence the separate configuration.


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'Context' object has no attribute 'view_layer' in Python Script
I'd like to run the script here
but hit an error on the 2nd line:
view_layer = bpy.context.view_layer
Traceback (most recent call last):
  File "/usr/lib/python3.6/code.py", line 91, in runcode
    exec(code, self.locals)
  File "<blender_console>", line 1, in <module>
AttributeError: 'Context' object has no attribute 'view_layer'

Autcompleting the bpy.context object does show there's no view_layer property...maybe the docs are outdated?

I would suggest to check which version of the API is used, as there is a possibility to search older as well as newer (beta version) API docs. If it's not for some special functionality change from 2.79, i would not see a reason to not update to 2.81.

The manual page you've linked is for Blender 2.81 and is up-to-date. If you're using an older version of Blender you'll have to consult the matching version of the manual. The documentation of bpy.types.Object in Blender 2.79 can be found here.


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Every time I render my screen turns blue

This is what my render screen looks like. The thing I am trying to render is a parallax or 2.5d animation

Could you share a .blend file so I can see the issue? This doesn't really show what could be wrong in the scene.

Does this always happen or only with that specific scene? If it's the former, what is your CPU and GPU?

it renders then stop rendering and keeps being that color

i cannot figuire out how to share a .blend file on this thing

i am using eevee


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Why didn't installing Blender 2.82 delete 2.80?
Installing version 2.82 did not automatically delete version 2.8. Is it standard for a new version of Blender to not delete the previous version in the installation process?

as thibsert you can have different versions of Blender, even different copies of the same version, it might help sometimes, because you could want to go back to a previous version, or you can launch a render on a copy and work on another one

It varies with the OS and the method of installation (archive, repository, installer...).
It's totally fine to have two (or many more) different versions installed, that shouldn't cause any issue. Of course, feel free to manually uninstall the version you don't need anymore.


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Select vertices, edges, faces of individual objects
I add 1 circle using this code
ret = bmesh.ops.create_circle(
        bm,
        cap_ends=False,
        radius=(10),
        segments=3,
        )
del ret
edges_start_a = bm.edges[:]
geom_start_a = bm.verts[:] + edges_start_a
verts_start_a = bm.verts[:]

When i add a second one using the same code only different variables
ret = bmesh.ops.create_circle(
        bm,
        cap_ends=False,
        radius=(10),
        segments=3,
        )
del ret
edges_start_b = bm.edges[:]
geom_start_b = bm.verts[:] + edges_start_b
verts_start_b = bm.verts[:]

All the variables of the second circle is combined with the first one
I.E. edges_start_b also has edges of edges_start_a in it
How can i split these? Or at least get the vertices and edges and faces of each individual circle?

I'm assuming, that bm is a bmesh object. Obviously, the bmesh object will hold all verts, edges and faces that you add to it with any operation.
You should improve the following

Don't del ret. It should be put in a global scope where ret is accessible later anyways. If it goes out of scope python will delete it automatically. You're using a dynamic interpreter language, so you can use its features. Even just not pointing to the return variable bmesh.ops.create_circle(bm, ... ) will delete the pointer.
Your code won't compile. Always post working code snippets (mwe) in question. You'll be saving everyone a lot of time. (A) Others won't have to rewrite your code and (B) your problem may be in the code you didn't post.
Read the documentation. The method bmesh.ops.create_circle actually return a dictionary with the newly created vertices.

From the api:

Returns
verts: output verts
  type list of (bmesh.types.BMVert)
Return type
  dict with string keys

With the returned dict we can point to the verts. (Obviously, now that we're using the returned object ret don't delete it.)
verts = ret['verts']

Each vertex stores the linked edges.
verts[0].link_edges

The updated snippet could look like this.
import bmesh

bm = bmesh.new()

ret = bmesh.ops.create_circle(
        bm,
        cap_ends=False,
        radius=(10),
        segments=5,
        )
verts = ret['verts']

edges = set()
for vert in verts:
    for edge in vert.link_edges:
        edges.add(edge)

edges = list(edges)

So, what's going on at the end? Why are we creating a set() and then converting it to a list?
Each vertex of the circle, will have two link_edges. However, the connected vertices will share an edge. This means, that if we just add all of the linked edges into a big list, each edge will show up twice. That's why, I use a python set. In a set each element is unique. Adding items to a set with the add() method will not do anything if the element (the next edge) is already present in the set.

Thanks for your answer learned from it
Following this example https://docs.blender.org/api/master/bmesh.ops.html?highlight=bmesh%20ops%20bridge_loops#bmesh.ops.bridge_loops
The operator example does delete ret whole time. so that's why I also did it

Yes, I saw that. I think they del the ret variable, because they're assigning it another value in the next line and want to avoid confusion. By using del they are saying that whatever was in this variable is no longer used, although the same variable name shows up shortly after. You can read it here: using del can be useful to show intent. - I know in the case of del foo that the intent is to remove the variable from scope. It's not clear that foo = None is doing that.

Btw, welcome to Blender.SE. If this answer solved your question, you can tick the checkmark to the top-left of the answe.r

Thanks for welcoming me.I have 1 more question related to this
the list that I get back is different
[<BMEdge(0x000001650DE89220), index=3, verts=(0x000001657B5F0130/4, 0x000001657B5F00F8/3)>]
{<BMEdge(0x000001650F812690), index=9, verts=(0x000001657B5F01D8/7, 0x000001657B5F01A0/6)>}
See the second list I got using your code
It closes with } instead of with ]
Any idea how to fix this ?

Added a new paragraph, clearer now?

Yes its clear. learned some things again :-) Thanks @Leander


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best way to select edge to use bmesh.ops.bevel
I would like to bevel some of the edges of my object.
I tried this code (works but is not consistent)
bm.edges.ensure_lookup_table()
ebd = [
        {'idx': 20, 'profile': 0.5, 'offset': 0.005, 'segments': 10},
    ]

# first get the edges
for i in range(len(ebd)):
    ebd[i]['edge'] = bm.edges[ebd[i]['idx']]

# bevel each edge
for i in range(len(ebd)):
    e = ebd[i]['edge']
    bev_geom = [e.verts[0], e.verts[1], e]
    p = ebd[i]['profile']
    o = ebd[i]['offset']
    s = ebd[i]['segments']
bmesh.ops.bevel(bm, geom=bev_geom, offset=o, segments=s, profile=p)

I noticed that the index number of the edges changes. So every time I run this code another edge is bevelled. maybe I do something wrong idk.
What I did noticed is that the vertex number is the same every time I insert the object. So I was wondering and could not find any on the forum so far that shows me how to select an edge based on 2 vertices. Or how I can select the edges I want and then bevel them so that every time I insert the object the correct edges are bevelled.
Another code I tried is
    indices1 = [3, 15]
    vertices = [e for e in bm.verts]
    v_edges = []
    for vert in vertices:
        if vert.index in indices1:
            vert.select = True
            v_edges = v_edges + [vert]
        else:
            vert.select = False

bmesh.ops.bevel(bm,
                #bev_geom=v_edges,
                geom = v_edges,
                offset=0.005,
                segments=10,
                profile=0.5
                )

This will obviously select 2 vertices.
Can i use these 2 vertices to select the edge between them?
Regards

You won't be able to do much about the indices changing whenever you add geometry with an operator.

@FrederikSteinmetz
And it is not possible to select and edge based on 2 vertices?

I tried thes Lines:
import bmesh
from bpy import context as C

m = C.active_object.data
bm = bmesh.from_edit_mesh(m)

indices = [0,1]
for e in bm.edges:
    if e.verts[0].index in indices and e.verts[1].index in indices:
        e.select = True
        break

The selection doesn't show up in edge select mode, but if you go to vert select, and back to edge, the edge will be correctly displayed as selected.
How to continue from there with the operator, I have not tested.

It only selects the last edge of the object
No matter what numbers i give in it does not select any other edge then 0. And I paid attention to the select mode

if I insert this into the success line: print("Selecting edge:",i)
and i+=1 under the break (less indented) it shows me a different edge selected every time I change the indices. However the visual selection for bmesh does not get updated when you run the script. Because bmesh is destroyed when you leave edit mode, or when the script terminates. You can continue to use your selection in the same script though, try it out, it might just work.

Frederik Steinmetz The code you gave works to select 2 vertices (it works) But can it be modified to select multiple pairs?
For example 3,15 and 4,16 and so fort

if you run a for loop over all desired pairs, I don't see why it wouldn't. .select adds to the current selection, so you can do that as often as you want without losing the previously selected


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How to transfer world rotation to local axis via drivers or constraints?
I would like to drive/constrain a local rotation axis of an target object by using drivers or constrain modifiers. Is there a way to do this in Blender?
I can copy rotation values by using a copy rotation constraint but it works for world axis only. Even if I set local axis in target, the world axis be be influenced alyways. Is this a bug maybe?
Situation: Imagine you have a car steering wheel and want to copy the rotation of one of your front wheels.
Best wishes
Chris

hello, maybe this will help : https://blender.stackexchange.com/questions/228806/rotating-car-steering-wheel

OK. It works. Thank you for the hint! It was my fault. I tracked the wrong object... it was a carelessness... :-)

Note: The linked solution above doesn't work correct if you've a driver added to the rotation axis of your wheel target. Just for info. So you have to create an invisible control dummy wheel without drivers. I'll show my solution in my upcoming tutorial on YouTube.


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Grease Pencil Line-art layer: How to place it into a render pass / view layer?
This is the closest I get to have Grease Pencil Line-art modifier as a render pass:

But it's very aliased and not a very good approach. How to do it better?

Here are the steps how to render pure Grease Pencil layers into view layers:


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How can I export a street material using procedural textures to Unity?
I tried to make a road texture with puddles by this tutorial: https://www.youtube.com/watch?v=1e-S0DM5hlc. My problem is I can't bake the shaders, (puddles etc..) The first picture you can see the shader editior. In the second picture you can see how it looks in blender. In the third picture you can see how it looks in unity.

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You can't bake the shaders because you don't know how to do it or what exactly is the problem? Because you cannot export things like math nodes, bump nodes, color ramps etc. to Unity. These are Blender-specific features. I'm not familiar enough with Unity to tell if you can somehow recreate them there, but certainly you cannot simply export the material in Blender and import it into Unity.

Hello, I bake the textures but after import in in unity the puddles and etc is gone. (You can see on the third picture). But if I can't export color ramp etc. to Unity how can I make a puddle for my road texture?

You have to bake the Roughness map too, then in Unity switch the material shader type from "Standard" to "Autodesk" and maually add the Roughness map into the roughness slot. This will give you the puddles effect.

I put the Roughtness map into the roughness slot, but this not really loook like a puddle. https://ibb.co/wgf3j6H   https://ibb.co/pwfj86K You can see on these pictures.

Normal map is missing. The HDRI reflections also help to sell the puddles, so you will have to build some reflections in Unity too.

https://ibb.co/9NLb8SL  https://ibb.co/x19jRHk  https://ibb.co/c2xZ2dC https://ibb.co/w7tvdDh  It still doesn't look good. Any ideas?


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Problems animating bones
I'm trying to do some animation but, for some reason, when I try to move the arms and make new keyframes, they keep connecting to the old ones. Even after I try to alter them separately, they keep ending up with the exact same pose! Is there something here I'm doing wrong?

you cannot change that manually. Blender just shows by that connections that your values on both ends are equal. If you change the value on one side, the connection  will disappear.

Hello, maybe share your file: https://blend-exchange.com/

You are setting the pose values and then adding the keyframes, right?


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Fluid Simulation: Inflow is stretching to the edge of domain when baked
Here you can see an animation of my fluid sim. The inflow is that small black circle.

For some reason, the fluid flows in from the space between the inflow and one edge of the domain...

Here are a couple other views showing the domain and inflow windows.

How might I go about fixing this?
Additional notes:

I get "No active UV layer found in the object" when I bake via the render panel (not when I bake via the physics panel). I don't know if this is significant or not.
Object scales are all at 1.0x, 1.0y, 1.0z.

weird. Have you checked if any transform needs to be applied? Can you share the .blend?

The normals of the inflow object are inverted. Flip or recalculate them.

Took me a while to remember how to do fluid sims but you appear to be correct!

This saved me so much frustration, thank you!