text:
(Geometry Nodes) Merge curves at intersections into mesh
My goal is to take a collection filled with curves and merge them into 1 mesh object (without faces). I want them to be merged at intersections of given curves, I only work with 2D curves (XY spanning curves, top-down view), but 3D approach might be useful for me later on (not a requirement though).
I already have something that kind of works. My current approach is:

I'm looking for something more stable and less prone to my error in choosing correct magic constants. I attach a file where the curves are in such state that they are not merged. Also it looks like Merge by Distance iterates indices and so not all vertices that are originally some given distance away from each other get merged into one but rather it merges one by one and sometimes ends up making mess:
Expectation:

What happens:

Ideas: Was thinking about proximity node or raytrace node but didn't figure much out. Also if there was a way to fix the center point in my current approach after the merge, that would be nice too. Something like select point with more than 2 neighbors (intersection point) and move it based of directions of neighboring edges or something like that?
Thank you in advance for time and effort.

See: https://blender.stackexchange.com/a/264140/60486

This does the trick with a good precision
Using a mesh boolean (must be "union" and "exact") calculates intersections automatically.
The caveat is that you need a volumetric mesh (just edges aren't enough). So we use a low res circle so the intersections are found.
The radius of the circle in my test was 0.0001 (it appears as 0 in the node, but it's 0.0001).
Now, if we merge by distance with more than 2 times the circle radius, we convert every circle back to a single vertex.
The multiplication ratio for the merge also depends on how parallel the curves are. If they're too parallel, some merge might not occur properly.

Another option is to use high resolution and brute merges.
The downside is that I can't seem to decimate the mesh or dissolve vertices after the operation. With a high resolution value, the crossings get a little displaced. With low resolution value, the result gets good precision, but the mesh gets too many vertices.

Thank you for your response. In my experience, the Mesh Boolean node took too long for bigger collections of curves and I kind of require interactability. But since I haven't specified it in my question, this is a working solution. Will mark it as one if no better solution is posted or I don't figure something out.

@Poncaada, check the new answer, it's less precise, but doesn't use faces or boolean.

@DanielMöller I think you meant to say "With a low resolution value, the crossings get a little displaced. With high resolution value, the result gets good precision, but the mesh gets too many vertices."

Well... high resolution means a low value.


text:
Geometry nodes - Splines (Curves) Merging Neighbors CW/CCW
I have a star-shape mesh without faces, that I transform into curves using geometry nodes. When "Mesh to Curve" Node is used, it's all split in the center point into separate splines. When I then change spline type to Catmull-Rom, this separation makes problems with how I need the result to look.

Goal of this post is to have all possible pairs of splines, that are neighbors CW or CCW (meaning one spline will be part of 2 splines, one with the spline that is CW and one with spline that is CCW to it).

The colored lines (black, blue, red) are the curves I want as result
My idea: First sort the splines circularly using arctan2 of the vector between first 2 control points of each spline. Then use for loop node to iterate spline count times and merge i and i+1 spline (0 and n-1 as either the last iteration or separately).
Problems: There can be multiple star-shaped meshes inside one object which makes sorting by angle work only if you can separate them based on shared center point (or connection). Also I didn't figure out how to sample positions of just 2 start-points of each spline.
Desired final functionality: Splines are first duplicated once, then shifted in direction of normal (to both sides), then the merging of the neighbors is performed and then points that are farther than 'r' from center are deleted and the face that is the result is filled in. I don't ask of you this part but might be helpful for context (I might have missed something important) and if anyone has some ideas, I'm here all for them.

Current state:

Good question: the problem is clear, you mention both X and Y in the XY problem, you show you've done some work, the .blend file is complimentary. BTW, I see a problem with spline reversing logic: when you evaluate at index, this is not an index local to the spline, so the first index on 2nd spline is not 0.

Use Vertex Count to mark all verts that aren't an intersection - if one of these ends up as the start of the spline, reverse that spline.
Also capture indices of vertices - so that you can use the intersection (start of a spline) captured index as a unique index of a cluster. Now you don't need some awkward way to convert position to UIDs, and you can even support overlapping intersections of multiple clusters.
Capture the position at start of the splines, which are the intersections, to be used as a center of a Radial Gradient.
Offset evaluated position by above-captured position, which is the same as if you temporarily moved all intersections to the origin. Using such modified coordinate, the Radial Gradient is a one-node replacement of the arctan2 logic you proposed. I'm reading the angle at the end of the spline, but if you really need this to be 2nd point, you could e.g. subtract Endpoint Selection: 2;0 MINUS Endpoint Selection: 1; 0. Those selections I multiply by the angle, so that I accumulate nothing except for the one point of interest and capture that on all points.
Since the above is saved an all points, it can be interpolated into a spline domain, and in that domain I can sort all elements (all splines) by angle).
Now use Accumulate Field to calculate indices local to each cluster, as well as a size of that cluster needed for wrapping using modulo.
Duplicate Elements, as you suggested.
Split to instances. For the original (Duplicate Index = 0), use the local "In-cluster Index" as group ID. Keep in mind this means clusters reuse instances, i.e. first splines of all clusters end up in the same instance. This breaks the possibility mentioned earlier about overlapping clusters, but the fix to that isn't hard... Now, you want to pair this spline with another, so for Duplicate Index = 1, since this D.Index is added to the Group ID, it will end up with the next ("In-Cluster Index" higher by 1) splines. Unless it's the last spline, in which case the modulo reverts it back to 0.
The end is obvious, in particular the instances can be realized just after "Merge by Distance", as I only used instancing to separate this merging process.
"Scale Elements" is my lazy, imperfect way of moving the points. You may want to scale by very little, compare the direction in which the intersection point moved to its normal and if the dot product is negative, flip the normal, to then just offset by normal.

Result:

Face filling:

source: Stack Exchange

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

sort: votes


text:
Selection tools in Edit mode not working
In one of my Blender files all the selection tools (select box, select circle, select lasso), as well as selecting by clicking, outside of Vertices selection mode (edges and faces), DON'T work. Functions like select all, select random or checker deselect DO work. The tools DO work in Object mode.
I have tried adding a new cube into the scene. It doesn't work on it either. Other Blender files work. I think I might have activated something by accident. Any ideas what this could be?
Gif that shows the isssue:

There was a question a short while ago where someone could not select parts of the mesh. Your issue looks a bit different but without seeing your actual file it is hard to tell for me what is going on there. Check out my answer on the other question if there is any useful information for you: Can't select or edit certain parts of my mesh during retopo

Thank you for the idea. I have checked, but it is not the issue I'm facing. I understand that it's not more than a guess without the file, but I can't share it. I have tried to recreate it and if I do, I will share the file.

I recommend you to reset your Blender settings:
File > Defaults > Load Factory Settings

*If it's not enough:
(After you've reset the settings):

Create a new Blender file

Append to new file all objects from your current project: File > Append

Save the new file

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


text:
How can I make a dragon/fish/monster fin using geometry nodes? Already have have the spikes, just need the fin!
First time on Stack Exchange, so I hope I'm doing this right! I'm in the middle of modeling a dragon and I would like to have a fin running down her back supported by spikes. I modeled this by hand as a separate mesh from the body so I could use modifiers. Unfortunately, I can't get the dang thing weight painted nicely--even with a data transfer modifier. Therefore, I'd like to make it with geometry nodes! I have the spikes figured out, but I'm struggling to figure out how to connect the spikes with a fin. Here's what I made by hand:

And here's what I have with geometry nodes so far:

In a nutshell, I duplicated the verts running down the dragon's spine and converted them to a curve. I then instanced a cone down that curve and used a float curve to set the Z scale. It deforms beautifully with the armature, but I am am VERY new to geo nodes and I have absolutely no idea how I would go about connecting the spikes with fins. Any ideas?

Could you model a spike and a fin as a single object, then use it instead of a cone to instance with a Object Info node ?


text:
Blender to Aftereffects - EXR-multilayer with AGX Color profile workflow
I havebeen trying to render all required into EXR Multilayer and composite inside Aftereffects, But the problem is EXR inside after effects with AGX color profile not looking as good as PNG output. I am missing out some color convertion steps. Please help here who have found solution for this. I am facing issue for AGX color workflow.
Thanks.


text:
Is it possible to use a heightmap to create displacement and use the object as a modular asset with the edges alligned with each other?
I'm trying to make my wall a little more interesting by using a heightmap on a subdivided face, which I then want to decimate to make it a little more manageable. But this method doesn't create seamless models, which is important in my case as I want to duplicate the object and use it side by side. The edges are fuzzy and the verts are not aligned at all.
My heightmap is seamless and the UV of the face covers the entire space.

You could scale the UVs a bit so that the model has the transitions from tile to tile and then cut the model with bisect operator at the seams to have them smoother. Manual work would be needed to fix the seams to match exactly though.
You could align the seams with geometry that is repeating to see if it could  make it easier, but I have not tested this. I suspect the problems are caused by geometry edges, so it could work better if you don't have the edges at the seams of the displacement map, but have extended geometry there instead. This could also be caused by image compression though.


text:
What is causing blender to crash when joining meshes
I am using 4.1 stable and I noticed this morning when trying to create a ring with multiple mesh objects that when I try to join the objects to one for 3d printing blender crashes. I typically use Ctrl J to join meshes but I also tried Boolen Union (ctrl shift numpad +). Is there some setting I had set wrong in blender to prevent joining meshes?  The objects don't have any modifiers on them

Worked fine here when joining all the objects to 'rounded Band' in one go. Select All, deselect the camera, Shift-select the band then Ctrl-J. (Blender 4.1.1)

Interesting doing it all in one go also just worked for me...but when I try to do it in parts it crashes

I can confirm, doing it piece by piece makes my Blender crash as well. Honestly I do not think this is a matter of "doing it wrong", because if you use a tool incorrect it should only give no result or not the desired result. Crashing should not be Blender's answer to an incorrect use... I would understand it if it would require too many resources that it crashes, but I do not think this is the case since joining all at once works...? I would rather file this as a bug report. In my test, joining two objects always works. Then selecting another and trying to join with the previous, it crashes.

But it seems to be a problem with the objects. Appending them all in a new file makes Blender crash as well whenever you try to make a second Join operation. But it is not a bug in 4.1.1 itself, joining more than once works in a new file with new objects.

I think the problem is from trying to join multiple objects that had modifiers applied to them. I was able to join 10 cubes piece by piece but 10 cubes that I applied modifiers to caused blender to crash

Download latest experimental Blender from https://builder.blender.org/download/daily/
Don't load previous settings.
Try doing the same with the least amount of off-topic steps.
Still crashes = report as a bug. Blender must NEVER crash (Blender devs see every crash as a bug)

If it's not too much of a problem, try disabling all the non-default addons that you have and try replicating the issue in a fresh file.
Overall, this really sounds like a bug. Don't forget to report.


text:
I can't find bake to F curve
I was trying to find bake to F curve in graph editor so that I can make displace modifier react to my wav file. I tried finding it inside Key and channel but it's still not there. My blender is 4.0.2 and Im on Mac. Please Please help

you have to insert one keyframe before you can do that.

It has changed in a recent update of Blender. It has been renamed : Sound to Samples :

After doing it, you may want to convert your samples to keyframes with Samples to Keys, shown as half-dotted arrow.


text:
What is the best way to create a clean 3D dotted line on a surface using a bezier curve?
I am drawing bezier curves onto 3d objects for a project. So far, I have been doing it like this:

Add a new bezier curve
Go into edit mode, select the draw tool, set depth to surface, and draw my curve with the mouse

After the curve is drawn, I go into Data --> Bevel, and create a round thickness of about .02m, so it looks like a noodle. I also then delete the original bezier curve vertices that were created when I added the curve. All that remains then is the bezier curve that I drew on the surface of my object.
My issue is that I need this curve to look like a 3D dotted line. I have tried working with array and curve modifiers, and I have tried adding a checkered texture to it and tweaking settings to work on transparency, but nothing has really worked yet. If I try to add a sphere with an array modifier and fit curve to the bezier curve, it only wants to align with the original curve, not the drawn curve.
I also installed the alpha version of blender 4.2 and used the grease pencil 3.0 so that I could use some of the new features, but that didn't work out either.
Any helpful tips out there for how I can create a clean 3D dotted line on a surface? Happy to provide more information/screenshots, etc. as needed. Thank you!

Dotted line from Bézier curve (Geometry Nodes)
I don't think this method satisfies the conditions you established, to be clean and probably perfectly on the surface. Here it is nonetheless.
You can use Geometry Nodes to delete one edge every 2 edges for example. In my example, I'm converting the initial Bézier curve to a mesh. Deleting a vertex/point on a curve doesn't create a gap, instead the curve would still be connected.
I can't say it's the best way, but it's a simple one. Here is the node setup you can use :

The parameters you should tweak for your case are :

Length : this is the resolution of the curve at the very beginning. In my case, this is also the length of one dot. You could change that with a little bit of math.
Radius : this is the thickness of the line.
Dot spacing : a custom input which let you choose the spacing of the dots.

This methods works well if you don't mind the cylindrical shape of the line elements. If you want the line to be flat, it would be achievable with Geometry Nodes but would require some more nodes.
You may want to increase the Offset of the curve Draw tool, in the N panel, so that the curve doesn't sink too much inside the mesh.

Finally, an example of use and the blend file.

Blend file

Hello, and thank you so much for taking the time to respond and provide pics + a gif. I am working on implementing this now. Just one point of clarification - can you expand on what you did with the "Add" and "Floored modulo" nodes? I'm fairly new and not sure exactly which nodes to search for to add those to the tree.

I found them in Math nodes and was able to connect the rest. This is a great solution, thank you so much!


text:
There are some weird edges and shadows in final render Cycles
I'm using boolean modifier to create some holes and it works fine in eevee render and everything is smooth but in cycles I get some weird edges and shadows.

Could you provide your Blender file using https://blend-exchange.com/ ?

It seemed it was a bug in blender 4.1 which was showing me no difference between shade smooth and shade auto smooth. these weird edges occurred because of shade smooth and blender 4.1 was showing me nothing in eevee only in cycles.
I accidentally switched to blender 4.0 and saw these both in eevee and cycles and fixed it.


text:
how to remove creases on circle mesh while using subdivision modifier
I'm using subdivision modifier on my mesh but there are some creases on it.

if I use inset or loop cut, it'll lose its circularity.
how to remove these creases?

Hello what do you mean when you say that you'll loose circularity?

Hello, I mean, it creates a flat surface at the top, not completely flat but its noticeable.

You need to inset but move up a bit the inset

Yes, i tried that too, it'll make smaller creases but not removed.

Hello, KMD, welcome to BSE. I think this is a  duplicate of https://blender.stackexchange.com/questions/70810/how-to-avoid-the-wrinkle-at-the-poles-of-the-uv-sphere , and quite a few others like it. Depending an how your spherical element is supposed to interact with the rest of your model, bear in mind as an option you can spherify any topology with a Cast modifier or 'To Sphere' operator.Technically, this post should close as a duplicate, but I see a discussion has started, so will hold off.

Thank you for your kind answer.

Inset several times the top face of your sphere A, create a sphere B (a default UV Sphere) at the exact same location that you rotate 90° on X, give it a Subdivision Surface with a level of 4, give your sphere A a Shrinkwrap modifier, that you put over its Subdivision Surface modifier, with sphere B as Target, it will make its surface stick to sphere B, apply the modifier:

Another solution would be to use another topology, like the ones here as suggested by Robin Betts, or subdivise a cube with a Smoothness of 1, or fill the top with a quad topology, etc:

The mesh A is not only a sphere, its a chess bead. When I set sphere B as target it removes the rest of the mesh.

You can choose a vertex group only

So, it just moves creases to sides of the mesh? Now I have 2 creases at both sides.

I'm not sure what you mean, could you please share your file? Also, you could use another topology than tris at the top

I mean, by rotating 90 degree of the sphere and using shrink, it removes top creases, but now I have 2 creases at both sides which belongs to Sphere B.
by creating multiple inset it will make the first crease less visible, But I just wondered if it can be removed completely.

And also by using another mesh for shrink, makes a undesirable cut between them,

Again, you can apply the Shrinkwrap on a vertex group only, or see my edit, you can use another topology instead of radial triangles, please share the object so that we can give a try

Hi, @moonboots .. holding off closing this as a dupe of https://blender.stackexchange.com/questions/70810/how-to-avoid-the-wrinkle-at-the-poles-of-the-uv-sphere and others like it.. but don't want to slam into this discussion.  KMD, if any of the linked answers are satisfactory, we should close this out.

Yes I also thought it was a duplicate but I couldn't find the answer you linked

@moonboots, thanks.. we'll just give KMD some space, as a new arrival :)


text:
Textures tranfer from high poly to low poly
I generated a 3d model in AI. I need to make it in low poly. I found a way to reduce polygons but then textures mess, couldn't make it right with the bake option. How can I edit an unwrapped image? Have suggestions on how to correct the transfer texture from the high poly model to low poly?

For the low poly version you can simply unwrap with the Smart UV Project then bake the Diffuse


text:
Making 3d pixel art water in blender with correct reflection in EEVEE
I am trying to make a 3D-pixel art scene that requires an ocean with reflections. I am using Lucas Roedel's pixel art addon. (https://lucasroedel.gumroad.com/l/pixel_art). His library essentially does the dithering for you and the cell shading all in EEVEE. However, I tried hard but the reflection did not appear. For example, I would add a cube to the scene and make it sit right on top of the water shader, but nothing happened. I know you can get reflections with baking cube maps but that also doesn't work and I don't understand why. Can anyone please help me? Thanks!

I'm not sure if I understand what you are asking for, is it a problem to get reflections with this addon or to get any reflections in general using EEVEE? If the latter, have you enabled Screen Space Reflections in the Render Properties?

Thanks for replying. I was just wondering if it is possible to get a reflective surface like water with pixel art dithering. I have enabled screen space reflections and I have tried baking the reflection with the cube map, but nothing works.


text:
NodeTree missing input attribute
I am using the super image denoiser and when I click create SID, an error happens. Here is the code:
import bpy
from bpy.types import NodeTree
from .create_denoiser import create_denoiser

def create_sid_denoiser_standard() -> NodeTree:
    # Create standard quality denoiser node group
    prefilter_quality = 'FAST'

    sid_tree: NodeTree = bpy.data.node_groups.new(type="CompositorNodeTree", name=".SuperImageDenoiser")
    input_node = sid_tree.nodes.new("NodeGroupInput")
    input_node.location = (-200, 0)

    output_node = sid_tree.nodes.new("NodeGroupOutput")
    output_node.location = (800, 0)

    sid_tree.inputs.new("NodeSocketColor", "Noisy Image")
    sid_tree.inputs.new("NodeSocketVector", "Denoising Normal")
    sid_tree.inputs.new("NodeSocketColor", "Denoising Albedo")

    # Standard Denoiser
    standard_dn = create_denoiser(sid_tree, location=(0, 100), prefilter_quality=prefilter_quality)

    # Link nodes
    sid_tree.links.new(input_node.outputs['Noisy Image'], standard_dn.inputs[0])
    sid_tree.links.new(input_node.outputs['Denoising Normal'], standard_dn.inputs[1])
    sid_tree.links.new(input_node.outputs['Denoising Albedo'], standard_dn.inputs[2])

    sid_tree.outputs.new("NodeSocketColor", "Denoised Image")

    sid_tree.links.new(standard_dn.outputs[0], output_node.inputs["Denoised Image"])

    return sid_tree

Here is the error:
Python: Traceback (most recent call last):
  File "C:\Users\...\AppData\Roaming\Blender Foundation\Blender\4.1\scripts\addons\SuperImageDenoiser\SuperImageDenoiser.py", line 83, in execute
    sid_standard_tree = create_sid_denoiser_standard()
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\...\AppData\Roaming\Blender Foundation\Blender\4.1\scripts\addons\SuperImageDenoiser\SID_QualityStandart.py", line 16, in create_sid_denoiser_standard
    sid_tree.interface.new_socket("Noisy Image",in_out='INPUT', socket_type="NodeSocketColor")
    ^^^^^^^^^^^^^^^
AttributeError: 'CompositorNodeTree' object has no attribute 'inputs'

If anyone can help that would be great.

Hello. Bryan, if @Gorgious heads you in the right direction, could you let us know in a comment, here, please?

Ups sorry this was actually not a duplicate. I retracted the vote

If I run your script in Blender 4.1 then I get an error in line 16, in create_sid_denoiser_standard: AttributeError: 'CompositorNodeTree' object has no attribute 'inputs'. That's correct because the API has been changed in 4.0. But it makes me wonder why your error message "sid_tree.interface.new_socket" is mentioned. That's not in the code snippet shown above.

By the way, a link to the add-on would be helpful. If you used this one [Addon] Super Image Denoiser 4.0.0 (SID) then it won't work in Blender 4.1 because of the API change.

@Blunder Thanks for responding, the reason why it was changed was because I was trying to solve it, albeit unsuccessfully. 2. Robin Beets, I am not sure what you mean.

@Bryan thanks for the reply but we still don't know which Add-on version you have tried :-( The console shows you're using Blender 4.1, so you need to download the Pidgeon Tool Bag as stated in the linked description.


text:
Blender 4.1 AttributeError: 'ShaderNodeTree' object has no attribute 'output'
I am using Lucas Roedel's pixel art addon. (https://lucasroedel.gumroad.com/l/pixel_art) I am encountering a problem that says: AttributeError: 'ShaderNodeTree' object has no attribute 'output'
Here is the section of the code that is wrong. I have looked at some discussions and apparently, Blender 4.0 removed outputs from node_groups in their API. I have tried some workarounds by adding some sockets, but there is another error code that says: Cannot add sockets to built-in nodes.
Can anyone recreate this error and provide a fix, please? Also, I have tried using both version 1 and 1.1 from the addon and they both have the same problem. Thanks for the help.
# Creates a group for the dithering part
for group in bpy.data.node_groups:
    if group.name == 'Dithering':
        bpy.data.node_groups.remove(group)

ditherGroup = bpy.data.node_groups.new('Dithering', 'ShaderNodeTree')
ditherGroup.outputs.new("NodeSocketColor", "Color")

outputNode = ditherGroup.nodes.new("NodeGroupOutput")
outputNode.location = (0, 0)

Here is the complete error output, it also mentions something about line 534, but I didn't really understand what was wrong:
Python: Traceback (most recent call last):
File "C:...\AppData\Roaming\Blender Foundation\Blender\4.1\scripts\addons\PixelArtAddon_v_1_1.py", line 534, in execute
    multiple_material(context)
File "C:...AppData\Roaming\Blender Foundation\Blender\4.1\scripts\addons\PixelArtAddon_v_1_1.py", line 304, in multiple_material
    ditherGroup.outputs.new("NodeSocketColor", "Color")
    ^^^^^^^^^^^^^^^^^^^
AttributeError: 'ShaderNodeTree' object has no attribute 'outputs'

There are examples of porting code in the 4.0 release notes.
Old
ditherGroup.outputs.new("NodeSocketColor", "Color")

New
ditherGroup.interface.new_socket("Color", in_out='OUTPUT', socket_type="NodeSocketColor")


text:
Can you use scripting to save the intensity of Light reaching a Face to a CSV file?

As depicted in the photo, I have placed a Light Object below and a Face above. The Face is divided into 16 sections as an example. In this setup, each of the 16 Faces receives a different light intensity from the Light Object.
I want to save the information on the light received by each of these 16 Faces into a CSV file. In reality, I plan to divide the Face into numerous smaller segments.
How should I write a Python script to solve this process?

Hello ! I don't think the information is readibly available but you can try baking the material to a texture and count the bright pixels relative to the dark pixels, or average the pixel values depending on the result you want

Thank you for the good answer. I'm currently analyzing using the brightness differences in the image as you suggested. I'm using the method of sending it to Python and then converting it to CSV. However, I wanted to do this all at once using Blender's script...


text:
Help Creating translucent liquid with density-based opacity
I'm trying to create a material for a liquid, specifically a ketchup spill, in Blender. My goal is to make it appear opaque in denser areas and translucent in less dense areas.
I've been experimenting with using a mix shader controlled by a factor derived from the Ambient Occlusion node. However, I've run into an issue where the areas that should be translucent turn black instead.

I have realized that when I reverse the order of the nodes I get the desired effect, but in the wrong part

I've tried adjusting various parameters, but I can't seem to resolve this issue. Any suggestions or alternative approaches would be greatly appreciated!
Thank you in advance for your help.

https://blender.stackexchange.com/questions/190914/how-do-i-render-white-liquids/ https://blender.stackexchange.com/questions/72495/create-a-gradient-effect-like-for-coffee https://blender.stackexchange.com/questions/107236/how-to-make-my-water-look-murky/


text:
Mysterious light streaks on a simple mesh
I'm guessing this has been asked thousands of times but I haven't been able to find a helpful answer yet:
I'm getting strange light striping & shadows that show up at specific angles on this object. The object seems to be ok Any ideas what is causing it?

From your image it looks like bad topology and a lot of Ngons. It could also be faces overlapping. If you are using EEVEE, try to increase your shadows resolution too

it looks like an artefact created by the low-angled light?

It's a problem with the soft shadows in EEVEE (they are simply not as good as "real" shadows in Cycles). What you can do is disable Soft Shadows completely in the Render Properties (but then the lighting will of course look different), or in the Shadows options set Cube Size to 4096 px to make the streaks finer (but still ugly) or in the settings of your light set Soft Falloff > Radius to a higher value, at least 0.25 or more (then the lighting looks of course different as well). Or just set the light higher above the object so that the angle is not so low.

Awesome thank you for all the suggestions. I'll give them a try.

That all worked great, thank you @GordonBrinkmann !

@Gordon or Matthew .. I don't think this one has come up before like this, so an answer or self-answer would be better than closing out as not needing one? If one of you has a moment?

@RobinBetts Maybe later... I was hesitant to write an answer, since I avoid using EEVEE most of the time because I prefer Cycles... so I just saw my comment as workarounds until maybe someone who is more familiar with EEVEE comes up with a real solution for this (if there is one that is not just about making it less bad like my suggestions).


text:
Why the extrusion doesn't work?
I'm following this tutorial on youtube : https://www.youtube.com/watch?v=5EV1elNFNSM
And I can't have a normal extrusion as on the video.
Does someone know why?
Here is what I have:

And I want to have this:

Would you mind showing screenshots of your object before extruding? And probably in Edit Mode so that we can see the actual mesh instead of just the outline? Maybe even better with Overlays > Face Orientation enabled? Because from what I see there I can only agree that it does not look correct.

This could be the result of attempting to extrude the split edges of an incoherent mesh? (Is this  EZ, in Global Transform Orientation?) The 'Normal' of a point or edge that's not part of a face defaults to the direction-from-object-origin.

please share your object: https://blend-exchange.com/

I don't know how to check that, here is my file


text:
FBX export is not showing all animations
I have a model with several animations on it using various methods (basic object movement keyframes, and an armature pose). I am also Mirroring these.
It looks like the issue is that Blender has created an Action for each one of these individually, including the mirrored animations. All I want is for the exported FBX to display all of my animations in a single, looping animation. What can I do to combine these so that I can view this on Sketchfab?


text:
AnimAll animations not exporting
I have made several objects in my scene animate using AnimAll, and a few objects animate using standard object movement using keyframes. These play back just fine in my scene, but when I export as .FBX for use on Sketchfab, only the objects animated not using AnimAll are working.
Is there something wrong with my export settings?

Most likely the Blender fbx exporter only supports exporting native animatable properties, and isn't prepared to export arbitrary non vanilla addon data

I think so, too. The problem is not everything that works in Blender can be transferred via export in other file formats - I guess there are even some parts in Blender which can normally be animated without using AnimAll that FBX does not support, using the addon which allows to animate even more properties might result in just more FBX incompatible animations.

Thanks, do you think Baking Animations down would work around this and help this export?

What is it that you animated outside the standard? Can't it be done otherwise?

I animated some rope-like objects that were using a couple of modifiers like Solidify. I see now the error and that these should have been animated otherwise. What would be the best method for that?

It really depends what you animated and how. Could you [edit] your question and share your file with us so that we can check ourselves what's going on and give an adequate answer?

The short answer is, the only animation data you can consider to be able to reliably export through formats like FBX and also import on a target software are:

Object-level or bone-level transform keyframes (Location, Rotation, Scale)
Shape keys / Morph targets

If you exported to other 3DCC softwares (Maya, Houdini, some game engine, ...), you sometimes have the possibility to use the Alembic or USD formats, which allows caching pretty much any mesh deformation and even generation (including I.E. physic simulations, modifiers effects, ...). But I doubt a web model viewer will support that any time soon, that's usually reserved for resource intensive usages. Sketchfab in particular supports importing USD files but with strict limitations:

The USD (Universal Scene Description) format, which was developed by Pixar Animation for 3D movie pipelines, is intended for the transfer of rich 3D models and scenes. Given the richness of the file type, Sketchfab currently supports only a subset of its features.

File types: USD, USDA, USDC, USDZ
Model types: Static (i.e., not animated), Polygonal (e.g., not point clouds or NURBS)
Shaders: UsdPreviewSurface only

Source:
Sketchfab Introduces USD Upload Support - Sketchfab Community Blog

Thanks so much, this is very helpful in understanding my issue.


text:
Bridging faces completely doesn't work
For some context, Im modelling for Roblox so the triangle count has to be kept lower than 10,000. I also do need to make it optimized so keeping it as low on the triangle count is the best case scenario. I also dont consider myself particularly great at blender but Im decent
My problem is when I use the bridge faces tool between 2 cylinders, both the same size and have the same amount of edges, but when using the tool, the bridge between the two cylinders goes really weird and sticks out like crazy. Changing the smoothness or any of those settings doesnt do anything. Please check the image to see the error.
Its extremely inconsistent and sometimes it works perfectly fine. I just need help on why this is happening.

If @Leander is right, I would further recommend, whatever the tutorials say.. when modelling, never scale in Object Mode, always scale in Edit Mode.

Apply the scale of your object.
Object Mode: CtrlA >Scale

Non uniform scale affects edit mode operations.


text:
Cannot load .blend file from Python script
I am struggling to find out the source of the segmentation fault I get when I try to load a file from a Python script (specifically a production shot of Charge). I try to call:
blender -b --python script.py

where the script contains:
import bpy
bpy.ops.wm.open_mainfile(filepath=path_to_file)

On the other hand, I can do:
blender -b path_to_file -o outfile

without issues.
I am honestly lacking an idea of what may cause this discrepancy.

I don't think it's possible to answer this with the information provided. If your question is about code, you have to share the code you are talking about if you want to get a meaningful answer.  You should edit the question and provide the full information about the issue.

Or is it just that what you shared? How do you specify the path?

Yeah, literally just one line of opening the file from the script causes segfault, whereas the same file can be rendered through the command line interface. The path is the absolute path to the blend file.

Oh, then ironically, the only part of the code you run you changed in the question is where the answer probably is. You should always post the code you run unchanged. But I also suspect there is more, isn't there? What good is it to just load a scene in Blender started in background mode?..

This whole secrecy about what you are actually doing when asking for help... I don't think it's very productive. :D

Command line and Python paths are written differently. "C:\some-file.blend" will work in command line, but Python string should be "C:\\some-file.blend" or r"C:\some-file.blend" so that the \ character is part of the string, because it alone is an escape character in Python.


text:
How do I get the brick texture to apply to all faces on an object?
I'm almost brand new to blender and I'm trying to make a Building with multiple faces, some of the faces are just a flat mirror whereas the others are applying the brick texture. I tried splitting the entire model into faces and texturing them individually but with no luck, I also tried using different object as reference and that didn't work either.

https://blender.stackexchange.com/questions/112843/how-can-i-make-my-procedural-brick-texture-map-correctly-to-both-a-cube-and-cyli/ https://blender.stackexchange.com/questions/90387/how-to-map-a-procedural-brick-texture-to-a-sphere/ https://blender.stackexchange.com/questions/70444/how-to-create-a-procedural-brick-texture-for-a-simple-building-without-object-si/70571#70571


text:
Exporting .fbx animation from blender and importing to Unreal Engine deforms mesh
I just got some character assets with a skeleton and mesh and am trying to retarget some animations in blender for the skeleton. I was able to retarget the animation in blender and import it into unreal engine, but there is an issue when I play the animation on a certain skeletal mesh in UE.
The animation works in blender and works perfectly with a male character in Unreal Engine, but when I try to play the animation on female skeletal mesh the breast deforms.

How can I start to debug this problem? What can be the issue here?
I tried to change the orientation of those bones in blender, but no success.


text:
avoid intersections of instances when changing their size
there is a simple bunch of nodes that allows you to avoid intersections of instances, but if scale = 1, and if you set a random value, then intersections appear

Could you detail what you are expecting ? To limit the scaling factor to avoid intersection ? To shift instances to remove intersections ?

the simplest solution, the main thing is that there are no intersections between instances with a random value scale, rather move the copies

To shift objects, I would recommend one of the two following posted approaches, in response to Generate non-overlapping spheres having different diameters in a mesh: lemon's and Rumen Belev's.

The simplest solution would be to set the Min Distance in the Poisson Disk distribution to a value as high as the max random radius of an instance. Of course this might leave unnecessary gaps between smaller instances, but how many and how large those gaps are really depend on the actual values you are using, like the range between min and max radius for example.

ok, how to do this, can you send me a screenshot?


text:
Deform a flat object/wire on the surface of an irregular object

I modeled this sort of wire outline - that was a bezier curve that I added depth to - that's on top of the bulb-shaped object, and I want to make it be on the surface of the bulb as if you drew it on with a pencil and then carved it out.
I tried moving each individual vertex onto the bulb but they don't line up with the mesh of the bulb so there are parts of the wire that get 'submerged' in the mesh.
I've also tried to follow some solutions to similar questions but those didn't work with the odd-shaped bulb from what I've tried.
I also have a version from when it was still a bezier curve that wasn't converted to a mesh if that would be easier to work with.

Hello could you please share your file?

When you cannot even manually fit it on the surface and parts get submerged, I suspect you do not have enough geometry to perform this task. When placing two connected vertices on a surface, their edge is a straight line (mesh edges between two vertices are always straight), if the surface inbetween is curved you need more vertices to follow that shape. When you have a Bézier curve instead of a mesh, the connecting segment between control points is not necessarily straight (depending on your curve's resolution), but then you have to adjust the handles to make the curve fit the surface.

you could e.g. use a shrinkwrap modifier and a geometry nodes modifier like this:

The GN modifier converts the mesh to curve and and back to mesh with a circle profile.

the shrinkwrap modifiers moves your wire to your surface (i choose project here, of course this does not work, if you wanna wrap your wire all around your object), and the GN modifier gives your wire the thickness.

You should use an offset which "fits" to your radius of your curve circle node.

thanks, this worked! the geometry nodes really helped, its a solution I wouldn't have thought of but now in the future maybe I will

glad i could help


text:
How do I detect and fix overlapping geometry in 3d text
I'm creating a text object for use in a boolean modifier but I'm having trouble because the letters are overlapping, causing the modifier to fail:

Because the overlapping vertices are all exactly on the faces of the next letter "Select interior faces" doesn't find the issue
Is there any way to detect this happening and is there a way to programmatically merge the overlapping geometry together?


text:
Geo Nodes: Set object scale between spline points
Coming from 3ds max and Raiclone to create parametric models like houses I wonder how to change the scale of an object between 2 spline points on a multiple points spline:
I can get that to work between a simple curve using only 2 points already. I'd like to know if there is a way to get the information of distance/length between spline points to scale my instance mesh on a particular axis. Actually it's taking the whole spline length into account.
Also, would there be a way to select an instanced mesh from a collection from its length?
What I mean: Longer length between 2 points on a spline = select longer instanced mesh from the collection.
shorter length between 2 points on a spline = select shorter instanced mesh from the collection.
I hope everything is clear enough.

Hello and welcome 1k0, you can post your .blend here: https://blend-exchange.com/ So we don't have to rebuild your setup...

I would recommend to post this as a separate question : "Also, would there be a way to select an instanced mesh from a collection from its length?".

Thanks you two!

Hi, 1k0.. welcome to BSE. As Stef  suggests.. this does look like 2 questions? .You're welcome to ask them both.. in Stack Exchange's  format, that's the way to go, for clarity, and the searchable archive.

Here you are:

Basically i just take the 2 positions (index + 1, index) and store the midpoint (mix vector), the direction (vector subtract) and the distance to my "points" branch. Then i reposition the points on the midpoint (set position), rotate the instance along the direction (align euler to vector) and scale them by the distance (scale instances).

i instanced the icosphere just for demo purposes, so you know, where the point of the curves are.

Thanks a lot Chris! It's working great now :D

you are welcome


text:
Missing video file after motion tracking in VFX tab
"I motion tracked a video scene but when I re-open the file, the video file is missing (the tracking markers are still there though) How could I fix that or relink the file? Thanks"


text:
How to render an object inside (through) another object specifically
I have a character which consists of separate objects for the arms, legs, and one big piece for the head and torso. the character is basically pure white, with some principled bsdf mixed in for some shadows.The character has an object inside it's chest (literally inside the mesh), and I'd like that to be visible through the torso mesh but not through the arms. I tried flipping the normals and turning on backface culling, but because of the shadows it looks inconsistent. render layers don't seem to be an option because I'd like to rig several instances of this character and have them interact so the object inside the chest of one instance shouldn't be rendered over every other instances chest, just it's own. the effect looks okay if I make the character pure white with no shadows, but ideally I could keep the shadows and somehow make the torso transparent to just the internal object and nothing else or make the internal object always in front.
pictures:
current:

flipped normals and backface culling:

kind of what i'd like to achieve:

Hello, what shadow exactly makes it inconsistent?

@moonboots the since i've flipped the normals and turned off backface culling, the shadows are coming from the faces on the other side of my character's body. when the camera or character moves, the shadows make it obvious that they are being cast on the back side and not the front.

Could you please share your file? Remove the parts you don't want to share https://blend-exchange.com/


text:
Remove alpha from vertex color
I have some meshes that I baked the materials in to vertex color and it works fine. But when I export to FBX, all the vertex colors are RGBA while all the alpha values are 1.0. Is there a way to get rid of the alpha component of the vertex colors?

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


text:
Parenting and deformation
I've been working on a human for 2 days, but every time I parent the skeleton to the model, the legs bend the wrong way. I rotate the pole as I saw in an instructional vid, getting the skeleton to move correctly. However, when I then paint weights, the model deforms extremely -- as in, when I make it even slightly green, it deforms while I'm painting.
I then tried fixing the leg's pole angles before parenting, but even then, the weight painting always causes extreme deformities. It only seems to paint correctly when the pole angle is 0, but in most cases, having it at 0 doesn't allow for the leg to move correctly.
I saw an instructional video on this, and the artist was easily able to change the pole angle without affecting the weight painting.

Can you upload your blend? Would make it a lot easier for us to help you =)

Use this if you don't know how: http://www.pasteall.org/blend/

This sounds like you may have you have already 'Posed' your armature.
When an armature is already posed, parenting somthing to it will cause the child to take on the armatures pose. You need to only use 'edit mode' for choosing how the armature is set up. However this can be fixed:
Select the armature, go to pose mode, then Ax2 (or 1) just to select all bones. Then hit Alt+R, Alt+G, Alt+S, to clear all data on the bones.
When this is done your armature won't be where you wanted it, so go to edit mode to fix it back to the way you wanted.

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


text:
Array Modifier duplicating in wrong direction
I'm working on this tutorial and when I get to around 45:45 when he starts array modifying the floor with the desks, I got the floors to go up and line up correctly but when I try to array the desks they go down and they're on the X axis instead of the Z. Here's a picture of what's happening.  My median point dots are also all over the place and it makes them hard to follow, if there's any info on how to fix of prevent that I would greatly appreciate the help.

All you should have to do is apply the rotation. The hotkey to do this is CTRL + A -> Rotation.
An alternate method (that you probably shouldn't use if you want it duplicated on the x) is to put the value of one in some of the other value boxes (make the current on 0 first).

Also try messing with the directional factors on the left of the mod panel. Sometimes array gets stuck and needs a jiggle.

I ended up deleting all the duplicate desks and did your ctrl+a suggestion to the them. Then I added the array and duplicated and that seems to have fixed the problem, so thank you!

I'm glad I could help.


text:
Particle System does not stick to the mesh if the mesh is moving (global,local coordinate-system?)
I want to create something like a fire elemental, so I have to work a lot with the smoke simulation. In the flow objects I use FlowType: Fire. Now I've created a nice burning head, which is pretty easy, because the fire raises just straight to the top. And now I want burning arms too, but I have no idea how to give the fire the matching direction. I'm using a particle system to control the direction, but as soon as I rotate the mesh or something the particle system does not rotate with the mesh. I think the particle system is in the glocal coordinate system, but I would need it in the local coordinate system, so that it sticks with my mesh.
I hope I could clarify my question for you, thanks a lot for your answers.

It sounds like an issue you get when the modifiers are in the wrong order.

The modifiers are applied from the top down. In this example the particles are generated then the armature deforms the mesh which leaves the particles behind.
Check that the modifier for the particles or smoke is last in the list. Use the little up/down arrows to the right re-arrange the order.
You may want to alter the gravity settings for the particles to alter their direction. Particles usually fall down by default, you also only need a lifetime of one frame for them to generate smoke. Force fields can also be used to control the flow of particles and smoke.

I'm a bit troubled understanding your questions. For testing I just put a particle emitter on a cube and made that cube rotate. The particle system was animated with it and even the cube's rotation was added to the particle direction.
My guess would be that the cause of your problems lies more in the smoke / fire simulation. Have you tried animating the domain object with it (although that's probably tough regarding that you wanna animate a complete character)?
(Sorry but Stack Exchange gives me a 404 when trying to edit my last answer) I tried this a bit further, so my previous answer is partly incorrect. You don't have to animate the domain. - You have a mesh with a flow (fire) inside the domain - You have a particle system on that mesh and Flow Source set to that particle system - You animate the mesh, that way animate the particles and also the fire I admit that a particle system doesn't offer too much control over the exact particle vectors. Still those can be controlled by various settings like emitter object, emitter geometry, force fields etc. You cannot really set global / local vectors for some obvious reasons, the particles should be random, they should emit from faces (thus having an orientation from the face normal, otherwise the would just go up or to the side through the mesh)


text:
Technique to model a 3D button (Image attached)
I've got this image from a skeuomorphic calculator interface and want to model it in Blender.

I was able to create this within minutes, with the following technique : Subdividing a cube multiple times and pull the face in the middle upwards with proportional editing on. Then I lowered the circle for proportional editing and lowered the middle face again.

The outcome is not exactly what I want, since the topology is round and not squared with rounded borders and stuff like this. So I was wondering if someone knows a better technique to achieve this?

Add the loopcuts (Ctrl+R) and place them properly to crease the shape.

I'm not adding this as an answer, because Paul's comment above deserves to be the answer, and respectively he deserves the credit, however I'm adding a link to help you see what He's referring to. @PaulGonet, please add this as an anwer. Animation here: link

@Rick Riggs Feel free to add your answer (the solution presented in your .gif looks good). And I'll add mine. The more different answers the better :).

Here's the Text version of the Step-by-Step (please see Images below for visual reference of each step).

In Object Mode add a plane by hitting: Shift+A -> Plane.
Hit TAB to enter into Edit Mode.
Select all Vertices by hitting A. Hit Delete -> Only Faces.
Select all Vertices by hitting A. (**NOTE: Repeat the Next Steps 3 Times) Hit W -> S.
Add a circle mesh by hitting Shift+A -> Circle. Next scale it down by hitting S -> 0 -> . -> 5 -> Enter.

Ensure all Vertices are selected (A to toggle - you will probably have to hit this twice at this point), then hit W -> E, this will invoke the Bridge Edge Loops command to fill the gap between the rectangular mesh perimeter, and the inner circular mesh perimeter.

Hover your cursor over one of the newly created connection edges (eg. about the mid-point on an edge that spans from the perimeter plane to the perimeter circle) and hit Ctrl+R. Next move your mouse until you have the desired shape, then Left Mouse Click.

Refer to

for how to manipulate it afterwards.

Sometimes I feel, that the Blender stackexchange is on another level compared with the others.. These answers are always on point and great!

@cegaton I will circle back around and get this one covered, once I can get to something other than my phone.


text:
Balloon Air Physics
Is there any possible way to attach an inflated balloon to an object, in such way that the balloon will deflate through a path at a realistic rate and push the object?

Hi, Gamer ... I think since this will be at least partially a fake, we have to know what kind of pushing.. Along rails? Through the air?  preferably illustrate.. we like pictures, here :)


text:
Overridden delete operator does not work if object has been assigned to a variable
When I override the delete operator and then delete an object that has been assigned to a variable Blender does not use the overriding function. If I do not assign it, my function is being used.
Here is a minimal working example for the default scene with the cube being selected.
def delete_plot_object(obj):
    print("Using custom delete function.")
bpy.types.Object.__del__ = delete_plot_object

my_cube = bpy.context.selected_objects[0]
bpy.ops.object.delete()

However, without a variable assignment it works:
def delete_plot_object(obj):
    print("Using custom delete function.")
bpy.types.Object.__del__ = delete_plot_object

bpy.ops.object.delete()

I don't see any reason why a simple variable assignment would make such a difference.

Why do you want to do this? Why not just delete the objects in a way it's usually done? Actually, what is it exactly that you want to do here?

I am not entirely sure what is happening here, but I don't think you can call this overriding delete operator. I believe, delete operator might not be written in Python, you just call it from the Python API if I understand it correctly and you are changing "magic" method, not the operator... I don't think you should be doing this, whatever it is that you want to achieve.

see https://stackoverflow.com/a/1481512/10259287 and https://stackoverflow.com/a/8689983/10259287 so this works in Python, but you are not using only Python here, you are just using Python API to control Blender. You should provide more context and describe the actual goal and problem you want to solve. This is an XY problem.

i think this "del is called when the garbage collector happens to be collecting the objects, not when you lose the last reference to an object and not when you execute del object." is the most interesting statement of Martynas links regarding your question. So short: just don't do it.

I need to keep track of certain meshes in my scene. When they are deleted I need to perform some book keeping.
It is true that the delete operator is not entirely overwritten. However, I can use this to perform additional tasks when my objects are deleted.

The reason is simple, When you assign the Cube to my_cube and remove it from the scene, the object my_cube still here, so it not trigger __del__

Makes sense @XY. Looks like modifying the del function has been the wrong approach.


text:
Camera angle for 50% height hex grid
I have a scene containing a hexagonal grid, with an orthographic camera.
At what angle should I put the camera so a rendered hex would exactly half the height in pixels that it would normally be if rendered from a straight top-down view?
I tried a 45 degree angle, but the top face was squashed to about 2/3rds instead of 1/2. I guestimated based on what looked right and got 55 degrees, but I need it to be exact.

60°
Orthographic camera projects rays that are perpendicular to its plane. The length of a projected segment can be calculated using trigonometry.
In the first example of the figure below (left), a camera sees the segment from the top. The "projected" length of the segment is equal to its true length. The more the camera starts to face the horizon, the shorter the projection will be.

From the second example (right) we can easily figure out what is the general formula to get the length of the segment's projection upon the camera plane.
$$
P = R\cos{\theta}
$$
Where $P$ is the length of the projection, $R$ is the real length and $\theta$ is the angle.
In your case:
$$
P = \frac{R}{2}
$$
Then we can write the general equation as:
$$
\frac{R}{2} = R\cos{\theta}
$$
This holds when (one of the infinite possible solutions):
$$
\theta = \arccos{\frac{1}{2}} = 60
$$
In fact, the only combination of angles that makes a right-angled triangle whose one side length is half that of the hypotenuse is the 30-60 Triangle.

As the camera in its "angular resting" position is facing downward, the angle considered in the previous equations is the same angle you should put in the X rotation field.


text:
Export Blender Character animation to Cinema 4D Lite
I'm trying to export a character animation from Blender to Cinema 4D Lite. I've tried several exports, but I have been unable to have the animation come across. I'm afraid it has something to do with Cinema 4D Lite's lack of character animation tools (they're only available on the full, non-lite versions).
I'm new to Blender and tried some tutorials on baking the animation, but I'm not sure I'm doing it properly. I'm fine with not being able to edit the bones in Cinema, I just need the mesh to be animated.
Could someone lend a hand, or point me in the right direction?
Thanks!

I would use either COLLADA or FBX.
COLLADA
Copy these setting exactly. They can be found on the bottom left when you choose what to call the file.

Overview of settings

Apply modifiers:
Applies any modifiers like subsurf, generally a good thing since your mesh could end up different on the other side

Selection Only: If you have a hole bunch of other stuff in your scene, this can be useful to limit which objects you send.

Texture Options: Allow you to send textures.

Deform Bones Only: Removes all bones that don't influence a mesh

The rest of the setting are irrelevant
NOTE: You can only export Euler rotation, not Quaternion.
FBX
The default options work, just make sure you have Armature selected:

More Options:
Simply try each one of these the C4D Lite supports. Make sure to include animation + armatures in the setting in the bottom right hand corner (like mentioned above).

I really appreciate your response. I tried both methods listed above and neither seemed to work. The COLLADA file imports, but it doesn't seem to grab the animation, just the current frame. The FBX import give an error in C4D "Unable to read file". I've uploaded the file, if you want to take a look. Again, I fear this is a limitation of C4D Lite http://dwdigitaldesign.com/duderigged.blend1

Apparently I linked the wrong file. Proper link should be: http://dwdigitaldesign.com/duderigged.blend

@Dustin You will need to ask on a C4D Lite forum, I can't help with it since I don't own it. These exports have worked for other software... So it is probably an issue C4D light.


text:
Multiple smoke flows in one domain, with different colors
So I want to mix smoke with different colors in one domain object, I've found tutorials about that topic with Blender render engine, but not how to do that effect in cycles. I can define the smoke color in the node setup of the domain, but how can i seperate between my different flow objects?

You can use an Attribute node with color as a keyword to read color information from smoke (use colored flow objects).
Available keywords are:

color
density
flame
heat *
velocity *

They are now all defined in /addons/cycles/kernel/kernel_types.h though dunno if the last 2 are yet usable (maybe in some test builds) - edit - these attributes are usable from version 2.78 up - from left to right: smoke render, heat map, velocity vectors:

Smoke sim from benu:

Cool to see heat is now available!!!


text:
How to make car AI in my game?
I am making a racing game and I got a question. I want to make AI of simple street drivers(not opponents, but just simple pople). I want to know, how to make that AI that follows its path... Could you give me image or video tutorial?

You could try the Steering Actuator it has no official docs at the moment but there are some tutorials on the web.

But how do I make it follow to exact route?

Can you still make it for me?

Why do evryone vote down? Maybe I don't understand reason of this cause I am not perfect in English? Anyway, I just asked question- I want to make a caer that drives around my city independent of anything, but I dont know how to...:(

You can make AI drivers follow a path very easily. First, add an always sensor. Enable Positive triggering (pulse mode). connect that to an And controller. Then add a Steering actuator. (connect that to the And controller) change the Steering actuator's Behavior from Seek to Path Following. Then add a a plane, extrude it to whatever shape you want, then change the Physics type from Static to Navigation Mesh. Add an object to be used as the end destination. Your navigation mesh must connect from your AI driver's starting point to the ending point. Select your AI driver, and put the name of your Navigation Mesh in the input field entitled navigation mesh. then put your ending destination object's name in the input field for Target Object. if you did this correctly, your AI driver will follow the navigation mesh On The Shortest Route Possible to reach the end point. It is important to note two things. First, the navigation mesh is invisible and has no collision with anything else. Secondly, Because the AI driver will follow the path on the shortest route possible, the thinner the path, the better. Notice the path the object will take in the following pictures

From those two pictures, you can conclude that a wide path does not work as expected.
AI Driver's logic setup

OK! But I need that car to never stop... I need it to drive around forever trought streets of city...

Yes! I do it now, but i want to know, how to make it move when I crash into it...


text:
Why is my laptop lagging while using blender?
I'm trying to use Blender by following a youtube tutorial. The process is going pretty well, except my laptop is starting to lag and slowing down the process (while in the rendering part in the 3d viewport); making it hard for me to continue on. Is there a way that you or I can fix this please?
System Information
Operating system: Windows-10-10.0.22631-SP0 64 Bits
Graphics card: Intel(R) UHD Graphics Intel 4.6.0 - Build 31.0.101.4032
Blender Version
Broken: version: version: 4.1.1, branch: blender-v4.1-release

Hello, it may be because your file is too heavy, what it is exactly, how many faces does your objects have?

I'm not really sure. All I'm trying to do is add materials, textures to the object, and use geometry nodes. I'm not able to tell of which file is too heavy, or how many faces my objects have. ♀


text:
Place different objects on curve with exponential space between

Hello everyone, how can i place all these different(!) objects to the curve, with using empty as a space, rotation and location controller between them, but exponential increments or decrements.
As it does object offset function in array modifier.
Tried to make it in geometry node but have not enough knowledge

one way is using geometry nodes with this node tree:

so you resample the curve with the number of points of your collection of instances and then you reposition these points (set position) mathematically via the sample curve node, which spits out the position. The factor input is going from 0 to 1. If you give this not equidistant values, but e.g. powered values, you will get:

Hope it helps. Happy blending.


text:
Animate rotation
I've keyframed a cylindrical object to rotate, but, on playback, the rotation is different than desired.  The first keyframe shows the object at 0 degrees X and Z, 90 degrees at Y axis.  The desired, open ended rotation, which is reached by rotating on the red rotation axis (the same result as shown here being rotated on the white outside circle), then keyframed, is shown here:
However, after keyframing, the playback is showing something similar to this, which is not desired.
Have tried several transformation orientation settings, but can't figure it out.  Sure will appreciate the advise!

Actually I'm not sure what is going on with your model because it seems to be distorted by rotation. This could only mean you have some modifiers or other things which are varying dependent on the rotation - however you do not give any information on this in your question, so we cannot help you with the appearance without more details. You say the first keyframe shows the object at (0°, 90°, 0°), but the screenshot clearly shows the values (89.801°, 126.5°, 88.635°). And although the keyframe is not set to these values (see below), these are the ones currently used to show the object in the viewport.
But unless you did not change anything on your animation and the keyframes, what you show there is not what you will get if you playback the animation or render it:
You can see it in the colors of the keyframed values. The lower screenshot shows the rotation values in green, this means there are keyframes on those channels, but not on the frame you are currently on and the values are just interpolated inbetween. In your example, keyframes are on frame 1 and 40, but the current frame in the lower screenshot is 14, so the values are interpolated between the keyframes.

The orange color in the upper screenshot shows, these channels have animation keyframes, but the values which are shown have been changed and not yet been set as a keyframe - which means, moving the timeline or rendering etc. will reset them to the keyframed (or interpolated) values. The yellow color of the text in the top left where the frame number, collection and object name are shown also indicates that it has keyframes on the current frame.

When you are on a frame where you have keyframes and the values are the unaltered ones set in the keyframe, the color will be yellow.

Thanks, Gordon.  All of your points are correct.  I had initially made an mp4 showing each step along the way, but, as a newbie here, didn't know that mp4's weren't accepted format.  So I did struggle trying to pick frames which I hoped would make my point...but I now see that I picked a bunch of incorrect points.  Will do better on my next post.  Nevertheless, you've made several points that I'll explore in more depth.  Thanks!

@user187768 Hello and welcome. This site is not a regular forum, if some post helped you upvote it. If you feel it completely solved your issue consider marking it as accepted.

@DuarteFarrajotaRamos You have closed the question. Can answers be accepted when the question is closed? I have no idea because I have no closed questions with answers to try. I only know that you cannot write answers for closed questions.

@GordonBrinkmann That is a good question, I don't have one I can test with either, but I have no reason to believe they can't. According to this post yes, owners of closed questions can still mark an answer as accepted https://meta.stackexchange.com/questions/91827/can-an-answer-of-a-closed-question-be-accepted

I agree that this question should be deleted.  The link to the post https://blender.stackexchange.com/questions/129834/how-do-i-rotate-an-object-along-its-own-axis-windmill provided the answer to the question.  Thanks!

@user187768 And that's why we usually just close but do not delete duplicate questions here... someone with a similar problem might not use matching search words to find the other question, but maybe finds yours and then the link to the other answer.


text:
Animate color mix of yellow and blue to produce green
Very new to Blender, but lovin' it!  I have two objects, yellow and blue, which change transparency with animation.  When the items intersect while moving, I'd like to have the colors mix and produce green. (The objects intersect at frames 82 - 118 of the animation.)  I have separate nodes for the blue and the yellow objects. Will greatly appreciate advise on how to make this happen.  Thanks!

A blue transparent object will only let blue light go through. You won't get any green, no matter what's behind it.

Thanks for this input.  Can I use variables other than blue and yellow transparent objects that I can animate and create a green color when they intersect?

To explain in simple terms (AFAIK) : any blue object/light in Blender will only be one single wavelength. In reality, no lights or objects have this single wavelength, it's always about a range of wavelengths (lasers is a counter example). These ranges overlap between two objects and that overlapping enables behaviors such as subtractive colors as you know it. You can't reproduce that range of wavelength in Blender, you would have to cheat either by setting up a material emulating that, or through compositing.

Quick notes on colors
You can't have what you are asking for with Blender without cheating. Because of how colors are coded in Blender (3 channels for red, green, blue), all lights and colors are defined by a single value (or rather by a 3-tuple). In real life, almost all light is a range of colors that our eyes percieve as a single mean color. For example in the spectrum of the sun, green is the most powerful color yet we percieve it yellow because of other colors in the sun's light.
That's one reason why we can use RGB in digital content : our eyes are so bad and unable to separate light that we can represent almost all colors with only red green and blue.
Workaround
One way you can achieve this, is by using a greener shade of blue. The yellow light being coded as red and green, you'll get some green to pass through. In my example I've set the Color Managment to Standard.

The materials are simply Transparent BSDF
Animate transparency
You can use a Mix node. By setting the color to white, the material becomes fully transparent.

Alternatively, if you have a more complex shader, you can Mix Shader between the 2 shaders. It works the same as the previous Mix node.

Greatly appreciate, Lutzi.  Blender has been a great learning experience for me, and you've added a lot to my knowledge base.  Thanks again!

Making progress with your recommendations! (would send a screenshot, but not sure how to add it to this comment).

Great :) You can edit your initial question and add your progress if you want. No need for "EDIT: ..." just edit your question and add a section "Current progress" or something similar.

You could cheat with an Input > Light Path node that you plug into the factor input of a Mix Shader that mixes the yellow and the green shaders, in my case as the front object is made of glass I use the Is Transmission Ray output of the Light Path:

Thanks very much for the reply!

What proved to be an important factor was to use a lighter shade of blue.
I was able to use the Principled BSDF

By setting the Transmission to 1.0 for a transparent material, one of the main things that really helped was setting the IOR to 1.0.
Here's a screen shot of my nodes and the image in render view.
Much appreciate y'all's input!


text:
How to reduce graviation on single object?
I want to know how to make object's gravitation low(something like 1.0) or turn it off at all when actuator gives positive pulse. It should keep dynamics, evrything should stay as it is except it shouldn't go down so fast(note so it has also a control that makes it to move on Z axis using linear velocity).

OK! Again, I recieved answer and I can tell it myself:
Using constraint actuator with Damping bigger than 1(about 0.25), distance 1000 and -Z axis I achieved this result!:)


text:
How do I make settings in 1 scene affect other scene?
I am making a game and I wanted to find out, how to make a settings in 1 scene to affect (example, volume) other scene. Is it possible to import data from python and set it to other scene? I need to import a property from 1 scene and paste it in other scene.

So the thing is easy using globalDict:
def set():
    cont = bge.logic.getCurrentController()
    bge.logic.globalDict["item"] = cont.owner["item"]
def cell1get():
    cont = bge.logic.getCurrentController()
    item = bge.logic.globalDict.get("item")
    cont.owner["item"] = item

You can send a message to objects in other scenes.

You then use a message sensor to receive the message.

Will theese changes save when I switch between a lot of scenes? If not, how to make them save in that session?

Could you, please, upload a .blend example, if you have a free time?:)

I got question- what is subject?

I tested it- it does not save when I switch between scenes. When I switched to other scene, it did not copy property.


text:
Car Suspension - Getting Contact Depth and Speed From rayCast()
So I am making a vehicle physics wrapper for my game(aswell as one other game). I am doing kinda well with it, now I've gotten to suspension. And here I use simple method: I apply impulse downwards from each wheel equalient to it's load - that's the gravity. And I also apply impulse upwards from suspension.
I have found this link:
http://vehiclephysics.com/advanced/how-suspensions-work/
Where it's said that:
Fsuspension = Kspring * x + Fdamper * Vcontact
As you can notice already that springrate and damper force are constants. However, other 2 values are variables. I want to find out how to obtain contact depth(x) and contact speed(Vcontact) from a ray that I cast from wheel joint position downwards(in -Z axis relative to car). I already obtain the distance how far the ray reach, but I need to find out the compression using this distance. And also I need a way to determine the speed of contact.
Thanks already now! :D

Hm... Maybe this isn't the right place for this question?:D

OK! Here is the deal.
As I already told, I obtain the length of the contact ray already. I will not discuss it's obtanation here, it is just rayCast() method with some more math.
Now I do suspension_length - ray_distance.
This returns the contact depth or x value. To get the speed of it I make a property exdepth for my suspension and after the end of frame I store the depth(x) value into it. Than on start of frame I compare them like so: x - exdepth and than I get the contact speed value(Vcontact).
And that's it - issue solved;)


text:
Reduce width of a loop type model
I have a sort of loop type model(something like racing track) where there are 2 paralel curve-typed vertex loops. They're connected together like this
(simplified image):

Red lines - edges of outer loop
Yellow lines - edges of inner loop
Magenta lines - the connections between loops
Green dots - vertices
Blue dots - joint middle points(not actual model data, just imaginary thing for explanation)

What I want is to scale the magenta edges down(move green vertices which are joined with the magenta edges closer to each other) without changing the position of the blue points(the place where the magenta edges are or the place where the 2 connected vertices are). I could do it manually(select each 2 vertices and press S, .7, for example), but it would take a lot of time. Is there any automated way to do it?

You can ring select these edges and scale them done with 'individual origins' as pivot center.

This works, thanks. I'd reccomend you to create answer for this so that I can mark it as corrected and you gain reputation;)

Edge Slide
The idea is to pick one of the boundary loops and slide it by pressing GG in order to make it move next to the other other.

In order to use the middle point lines as a pivot, you should create a third loop in the middle with for example Ctrl+R....

...and then slide each loop by the same factor.

That is even a more beautiful workflow

@Dan Indeed! Carlo, this is nice!;)

I think the fastest is the one suggested (but sadly not yet written as an answer ) by @Yvain. This was proposed as a second alternative. Thanks for the appreciation anyway!

Set the Pivot Point to Median Point or Individual Origins:

Select the inner Edge Loop with Alt + RMB
Scale S it to your desired size

In Addition
The 'middle points' of your magenta edges will change. If you want the blue dots unaffected you will need to create an Edge Loop (Ctrl + R) between the inner and outer edge before you scale the inner edge:

Edit
If your shape is not circular you can try this:

Select the outer edge and extrude it E and confirm without translation, scaling or rotation
Switch to Edge Select and select all 'magenta' edges (e.g. Select > Edge Rings)
Pivot Point to Individual Origins
Scale S
Select and delete the unwanted Edge Loop X

This only works with circular shape. However, I have a shape that's more complex.

@AdriansNetlis Post edited. Maybe there is a better solution, but i hope it helps.


text:
Ubuntu and Alt keyboard shortcut
To do some stuff in Blender I need to use Alt key. It seems, however, that on Linux Ubuntu the left Alt can't be used for some actions(let's say, for example, Alt + RMB). However, when using right Alt key I than need to click the left Alt key, otherwise Blender goes to uneditable mode. I know that I could change Alt to something else, but I am used to it and I don't want to do so. So I rather wanna know how to prevent Blender from going into the werid mode(where I can't edit things).

This is because Ubuntu uses the alt key as a default-key.
This worked for me.
https://askubuntu.com/questions/521423/how-can-i-disable-altclick-window-dragging
regards

Thanks! This comes as a useful information, but now I got a question - can I somehow disable it only when Blender is running?

As far as I know you can only change the shortcut globally for the system/user.

I use Blender a lot, and in Ubuntu I can't use the alt button to select edge loops, because it is already bound as mentioned above.
As a software-specific work-around, I saved select edge loops as a quick favourite, and that gave me the usual result, with very little extra time.
I hope this helps someone!!


text:
Merge every two vertices in a loop
So I have a long loop of vertices. And I want to make each 2 vertices to blend into 1 like shown in image.

Currently I have a situation like on left(but much longer). However, I need to get situation as visile on right. Selecting every 2 vertices and merging them is long and exhausting process. I was wondering if there is a way to do it faster, in loop.

With the Edge Select mode enabled select the whole edge with Alt+RMB, then go to Select-->Checker Deselect. Set it up to select every second edge segment, then press X-->Edge Collapse.

Since 2.77-rc1 the same can be achieved via Select Shortes Path where you'd only have to select the first and last Edge and then use Mesh > Vertices Ctrl V > Merge Alt M, selecting Collapse as merge type. It might give some different or even faster results with more complex Topology as you can Use Topology Distance (Find the minimum number of steps, ignoring spatial distance).

May be also useful. I will try to see whether I can use the first method or this one:)


text:
How to grey out a modifier panel UI element?
I would like to achieve a greyed-out effect similar to this:

Except in the object modifiers menu:

The parameter can be accessed by bpy.data.objects["My Object"].modifiers["GeometryNodes"]["Input_23"]

Note in case of an operator it will be greyed out if the operator's poll method returns False in this context

How could this be implemented if I'm dealing with a geometry nodes modifier panel and not a custom made panel?

You cannot override this layout using the python API. You can create a whole new one however.

here is a small example:
import bpy

class SimplePanel(bpy.types.Panel):
    bl_label = "Simple Panel"
    bl_idname = "OBJECT_PT_simple_panel"
    bl_space_type = 'PROPERTIES'
    bl_region_type = 'WINDOW'
    bl_context = 'object'

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

        layout.prop(obj, "enabled_property")
        layout.enabled = obj.enabled_property
        layout.prop(obj, "my_property")

def register():
    bpy.types.Object.enabled_property = bpy.props.BoolProperty(name="Enable Field", description = "hi", default = True)
    bpy.types.Object.my_property = bpy.props.StringProperty(name="My Property")
    bpy.utils.register_class(SimplePanel)

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

if __name__ == "__main__":
    register()

so essentially you can use
layout.enabled = ...

to do that.


text:
How to modify the frame step using handlers?
I would like to modify the frame step right before and after the rendering process. This is what I tried:
import bpy

def step_change(scene):
    scene.frame_step = 5

def change_back(scene):
    scene.frame_step = 1

bpy.app.handlers.render_init.append(step_change)
bpy.app.handlers.render_complete.append(change_back)

Although I visibly see that the step gets changed to 5 during the rendering process, Blender still renders every frame. What am I missing?


text:
How to close the "View Animation" window using bpy?
I need to close the "View Animation" window using python. I found something like bpy.ops.render.view_cancel() but when I try to execute it, I get this:
Traceback (most recent call last):
  File "<blender_console>", line 1, in <module>
  File "/Applications/Blender 6.app/Contents/Resources/4.1/scripts/modules/bpy/ops.py", line 109, in __call__
    ret = _op_call(self.idname_py(), kw)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Operator bpy.ops.render.view_cancel.poll() failed, context is incorrect

Is there a way to fix this or any other method to close that window?

Close the top rendering window
import bpy

window = None

for w in bpy.context.window_manager.windows:
    screen = w.screen
    if screen.name == "temp":
        if len(screen.areas) == 1:
            area = screen.areas[0]
            if area.type == "IMAGE_EDITOR":
                window = w
                break

if window:
    with bpy.context.temp_override(window=window, area=window.screen.areas[0]):
        bpy.ops.render.view_cancel()

    print("success")

For the animation window, if we look at the source code of the operator bpy.ops.render.play_rendered_anim: https://projects.blender.org/blender/blender/src/branch/main/scripts/startup/bl_operators/screen_play_rendered_anim.py#L195
In line 195 it open it via subprocess.Popen(cmd),
So it is not part of Blender and is not stored in bpy.context.window_manager.windows.
To close external windows, maybe refer to:
https://stackoverflow.com/questions/49593533/how-to-close-a-window-in-python-by-name

This does a good job at closing the rendering window, but I would like to instead close the "view animation" window that appears when bpy.ops.render.play_rendered_anim() is called.

It seems can't ,can you close it via blender operator shortcut to close it?

Could you explain a bit further what you mean by that?

I mean bpy.ops.render.view_cancel is not used to close a View Animation window.  The window cannot be closed when I trigger the operator from a keyboard shortcut (render.view_cancel). The operator description is "Cancel show render view" and I think it is for cancel rendering window only.

Okay, that might be the case, yes. I managed to solve my problem by finding and terminating the right process using psutil.


text:
Problem with Texture Paint
I'm trying to texture paint an object. When I try to texture paint (with an image or even just a color) I get these lines that don't get painted. What's going on? I'm inexperienced and very new to blender so sorry for the question. Thank you!

Hello could you please pack the image (file > external data > pack resources) and share your file?

Hello and welcome. Please use a title that matches the content of the post. It should read like a question, be descriptive but succinct, unique and identifying, summarizing the problem so that anyone searching for similar issues is likely to find this. Remove anything superfluous, avoid using words like "this", "help with", "issue" or "question about", instead describe what "it" is. Remember, your title is the first thing visitors see, answers you get depend heavily on it. See What is the problem of asking “How do I do this?"

First thing to always remember is to check normals direction of your mesh - any faces pointed the wrong way will not paint except from the other side. Ctrl-N used to be the shortcut in edit mode to recalculate normals.


text:
blender4.1 gltf animation export settings problem
glb/gltf animation export settings are not as straight forward as previous versions. Anyone got tips for settings. The animation is a basic walk cycle from mixamo that needs to be a glb. new texture is attached. any help would be appreciated

Hello and welcome. This site is more geared towards direct questions about solving specific issues. Could you edit your question and rephrase it to illustrate a real use scenario and what specific issues you encountered or what your are unsatisfied with, so we can present an objective answer, rather than "general tips".

For me I would just set the [Animation mode: Active actions merged]
If it doesn't work also check the "Bake All Objects Animations"
I also uncheck "Shapekeys Animation" and "Sampling Animations"
Hope this helps !

perfect you did it man i love you


text:
How to make a sphere from many small spheres
I'm trying to make this (picture found on internet):

So I added 2 spheres. One big and one small.
For the big one I added : Particules > Emitter > Render > object > I selected the small sphere
And it gives me this :

Do you know why ?
(I tried to add "Rigid body" to the small sphere but it didn't change anything)
Thank you very much !

You want to instance your small sphere to each vertex on the large sphere. See the Blender Manual entry on instancing or instance on Points in Geometry nodes.

https://blender.stackexchange.com/questions/149877/sphere-with-curved-faces-or-sphere-of-spheres

add an icosphere, add a geometry nodes modifier, add this node tree:

adapt the radius of the uvsphere to your needs.


text:
Culling Objects Using a Culling Object
Today my question might be a bit complex, but I hope that Blender has an easy solution for this. So, let's say I have a scene with several objects in it and I have a background. The background is image/video which has some objects on it. Some of them are supposed to be closer to camera than my 3D models. I have a representative 3D model made for those objects, but texturing it would be real complex. Instead what I inted to do is to use it as a culler - wherever the object is, render the background(cull the other objects). Is this possible to do? Also, a solution for both - Blender Internal and Blender Cycles is needed.
Thanks! ;)

I guess it is something like object mask. Basically what I am trying to do is to use one object to cull others. Or, in other words, wherever that object is directly visible to camera, it must render the background instead of any objects).

UV Project modifier... maybe. But could you post some images to have a better understanding?

You might also want to have a look at this.  Instead of  fashioning a 3D model you just shape a 2D plane in the shape of the object that's in the bkd film.  Set it's transparency to .008.  That works in Blender's 3D window and using OpenGL rendering.  I'm not into Cycles but I imagine if a model can be used for a mask, a 2D plane could be also. (No transparency though)   The Question - drop to the bottom answer.  http://blender.stackexchange.com/questions/69832/realistic-rendering-of-mesh-together-with-image/69863#69863

Using Renderlayers
Position your masking objects on a separate layer. (In my case layer 2.)

Go to the Properties > Renderlayers Tab. Set the Mask Layer to the layer, which contains the mask objects. Note that you have to have the layers switched on in the scene for them to be included in the render.

Rendering this setup results in the following. The mask object renders as transparent.

If you do not wish the object to have a shadow, set it to a transparent material or turn off cast shadows.
Using the Material Setup
Cycles
Set the material to holdout.

Internal
Check Transparent, use Mask mode and set Alpha to 0.0. Disable Cast Shadows.


text:
Game Engine: Object with character physics shakes for some reason
I have recently started to make new racing game. I downloaded and imported smooth detailed car model(.obj). I added Character physics for it, so I can add W, A, S and D controllers to it. But, after I put my Character physics on it, it began to shake, when I pressed "p". I tried to check Physics only for 1 of all materials it had, but it did not help. I even unparented cameras and lights off it, but it still shakes. And I can not add controlers that can move it(they don't work). Who can help me?

The problem you are experiencing is due to the way blender calculates the collision for the quads on your ground plane. There are two ways to fix this, you can use a cube as ground instead (with collision bounds set to box), or you can set your plane's collision type to box, even though a plane is infinitely thin.
To help see the problem,
First turn on Physics Visualization.
This does not effect anything except what you see, so in the end it does not matter if it is on or off.

If your plane's collision bounds are not set to anything, blender automatically calculates it as if it were made up of two triangles.

However, if you set it to Box collision, This problem goes away.

If you use a thin cube instead for your ground, (with collision type set to box) this problem goes away entirely.

Another thing you can try is putting all of your logic bricks and python on a invisible low detail object, for a collision mesh, and having your detailed car as no-collision but parented to the collision mesh. Even if this alone does not remove the shaking, it will dramatically help performance.

It still shakes- does not work- I tried both of them...

OK! Here it is: https://www.dropbox.com/s/z7xeh4cucqnmd3j/6th_gear.blend?dl=0

I have no other way... Anyway, I solved it iwth using dynamic anyway... Now I got question- how do I make my car accelerate?

And, also, how do I make it look good when steering(my car currently keeps look the same when steering, but I want to make it so you can see side of car when you steer... And... If I make it accelerate, I need also inerce on it- how to make it inerce(continue its path after releasing gas)?


text:
How to export obj with texture coordinates and mapping applied to image textures?
I have an object with multiple image textures applied to different faces. In the shader editor, I added a mapping node and a texture coordinate node to change the scale/positions of the images on the object. When I try exporting it as a Wavefront obj., the changes I made don't stay. How can I apply the coordinates permanently? I am importing into MaxMSP.
I have already tried File>External Data>Pack Resources

Read through https://blender.stackexchange.com/questions/57531/fbx-export-why-there-are-no-materials-or-textures


text:
How to update the selecting state of the Mask Points in Image Editor and Movieclip Editor with Python?
I'm writing a new add-on for the masking. I tried hard to find how to update/redraw the Image Editor or Movieclip Editor, but I didn't find helpful information. I share my test code below. If you try the code, you might detect the selecting state (of the Mask Points) doesn't update or redraw.
If you find anything useful, please share with me. Thank you for your help.

NOTE::In the scripting workspace, switch the 3D viewport to the Image Editor or Movieclip in the Mask mode. You might need to change the index of areas[index] to make it work.

import bpy
area = bpy.context.screen.areas[5]
region = bpy.context.screen.areas[5].regions[5]
space = area.spaces.active
spline = space.mask.layers.active.splines.active
for id, p in enumerate(spline.points):
    p.select = True
space.mask.update_tag()

for area in bpy.context.screen.areas:
    if area.ui_type == "IMAGE_EDITOR":
        for region in area.regions:
            region.tag_redraw()

for area in bpy.context.window.screen.areas:
    if area.type == 'IMAGE_EDITOR':
        area.tag_redraw()

for area in bpy.context.screen.areas:
    if area.ui_type == "CLIP_EDITOR":
        for region in area.regions:
        region.tag_redraw()

for area in bpy.context.window.screen.areas:
    if area.type == 'CLIP_EDITOR':
        area.tag_redraw()


text:
Text in reflection
I'm new here in this blender world and I really need your help with a college project. I'm sorry if anything is written wrong as I'm using Google Translate. I am from Brazil
How to create a script in which I write the text I want and it creates an irregular surface that, when the light hits it at a certain angle, reflects the same text as the video.
How can I create something like this in Blender to simulate a real situation?
Video link

Hello, are you using Eevee or Cycles? In Cycles you can assign an image texture to a spot light. In Eevee I guess you'll need to cheat

In fact, I don't even know where to start, that's why I'm asking for your help.
The idea is to transform the text into a texture like in the video and photo and when reflecting the light it will show the text.

To simulate this in a physically accurate manner you would need to look into reflection Caustics, unfortunately Cycles doesn't excel at that, I'm not entirely sure it is actually even possible. You can fake it with a textured lamp https://blender.stackexchange.com/questions/57013/correct-vector-input-to-map-texture-light-in-cycles

https://blender.stackexchange.com/questions/154876/how-to-fake-reflective-caustics-in-cycles

Yup.. no way would surface normals / Cycles caustics be able to simulate this: https://www.youtube.com/watch?v=v2yV6IeL-Jw It would need a fake, IMO.

Thanks guys, all help is welcome. I see that this is really very difficult to do. The simulation in Blender has to be as close to a real situation as possible. Because the next step was to create the piece in some way.


text:
Combine different mixamo animations (first let the character their hand, then turn left and continue walking)
I am a beginner at Blender. I am trying to combine different mixamo animations together in Blender. First, I want my character to wave their hand at the camera then start walking and turn right, after turning right, the character continue to walk and then sit down (a series of action will happen after they sit down). This was what I did so far that it did not work.

First, I combined the series of actions that will happen after they turn right into one skin (by copy and paste the animation keyframes on the timeline).

Then, I created an "Empty" and put the character/skin that has the series of animations under this "Empty" (i.e. make the Empty the parent of the character).

then I rotated the "Empty" on the Z axis 90 degrees so its facing the same orientation with another skin I downloaded from mixamo (which is the one that walk and turn right - its called "Right Turn W_Briefcase" on mixamo).

4.Then I selected the armature of the combined action series (in step 1) and pressed Command+A => Apply "Location" to make sure the rotation I did with the Empty will be applied to the character/skin as well.

I selected the armature that is in the Empty (the one that I rotated) and opened "Nonlinear Animation".

I don't know what to do next. I don't know how to combine the skin that contains a series of action with the skin that turned right so that as soon as the skin finishes turning right, the skin will continue walking and sit down and complete a series of action in that same direction without return to its original position.
I hope what I described will make sense. Thank you so much in advance.

There are lots of YT videos online about combining Mixamo animations in Blender. A quick search shows this, this and this although some may not be for the very latest Blender versions. CGDive has done a series of tutorials here.

There is a great video which covers this topic comprehensively : Here: link on youtube