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best way to approach a coverage analysis
I have a script that places an object and moves a camera around this object following a predetermined trajectory.
What would be the best way to compute what percentage of the overall object's surface is being observed throughout the trajectory? Since there is a light source, seeing a part of the object would require some light being reflected off the object and into the camera - if I point the camera at a dark part of the object this should not count as "seen" surface.
I'm primarily wondering if there is an easy (script-based) way of approaching this.
Thanks!


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Computing scene luminance
I have a scene with materials and a light source with known luminous emittance. (for example, an interior scene, and clear day sunlight). I am looking to compute a physically accurate value for scene luminance (such as in this image from wikipedia).

Does anyone know how to set the scene, camera, and lighting up in such a way that the rendered pixel value is correlated to a real luminance value? The image can be processed in software outside of blender, but I must ensure that the pixel values make sense as they are being rendered.
Thanks!

I think what you want is "linear light" and a linear colour model.
Setting either "Displace Device" to "None" or "View Transform" to "Raw" under "Color Management" in "Render Properties" seems to do the trick:

Also pay attention to "Save As Render" in the image save dialog box.
A render with four concentric and equally spaced rings with maximum roughness and zero specularity around a point light source produces peak colour values of around [1.0, 0.29, 0.14, 0.09]— Mostly what you'd expect from physically correct inverse-square behaviour, with some margin from clipping and sampling noise:

I saved the result as a 16-bit PNG, which should give you plenty of bit depth to play with. You may also want to try EXR or RGBE, depending on your use case— My image viewer for those formats seemed to apply an sRGB transform by default on display, but the data itself seems to be intact.

Notes on interpreting the data:
As the output data is in the form of dimensionless RGB values, if you want physical units then you'll have to calculate a conversion ratio based off of a known lamp power output, surface albedo, and distance.
In my example file, the innermost ring has an RGB peak of 1.0 with an albedo of 0.8 at a distance of 1m from a point light source with 50W of power output.
The 50W of radiation at a distance of 1m will be spread across a spherical shell of 4π(1m)²=12.57m², so incoming irradiance at that distance should be 50W/(12.57m²)=3.98W/m². Outgoing surface radiosity accounting for the 0.8 albedo should then be 3.98W/m²*0.8=3.18W/m². So that means RGB(1.0)=3.18W/m², which in turn means that the radiosity at the other rings can be figured out by RGB(0.29)=(0.29/1.0)*3.18W/m²=0.92W/m², etc.
It may be more sensible to establish a conversion ratio using a Sun lamp shining perpendicularly on a full-albedo, full-roughness, zero-fresnel dielectric (non-metallic) surface than a point lamp. The tooltip says that "Strength" maps directly to W/m².
You can probably also put that ratios or its multiple and/or reciprocal into the "Exposure" setting under Colour Management in order to havea 1:1 ratio between the RGB values and your physical unit of choice. Note that if RGB goes above 1.0, then you'll probably want to use either EXR or RGBE as your output file format.
Always sample parts of your data by hand and check your numbers manually to see whether they make any sense, both based on your scene and relative to each other. Digital colour management is frankly a mess, and there's a lot that can go wrong at pretty much any stage of the pipeline when you're trying to pull physical measurements out of artistic software.
Further caveats:
Note that this also still technically isn't the luminance, as it's just the radiosity. Luminance is a measure of perceived light as detected by human retinal cells, so you'd need to apply a luminosity function to calculate it. You'll also need to make sure your render engine, file format, image viewer, etc aren't already accounting for the effects of the luminosity function.
From the fact that RGB(1,1,1) is white, we can also reason that even if interpreted as radiosity, the data is scaled against sunlight's spectrum rather than having a spectrally uniform power distribution.
Also note that Cycles and EEVEE run entirely in RGB, AFAIK, and not with continuous spectra. So if the spectra of your light sources and albedoes have a lot of spikes or valleys, the result will end up being further from physical accuracy.

Thanks that was super useful! Just another question to interpret the data coming from your scene: You used a 50 W white point light, and the first concentric ring's value color value is [1.0]. What does this tell me of the luminance from that point?

@gugiek Oh, good question! I suppose that doesn't actually tell you anything about the absolute luminance at that point, but you can figure out the absolute irradiance from 50W and the 1m distance, get the radiosity from that and the 0.8 albedo, then use that as your conversion ratio between RGB and SI units or whatever. Put that in the "Exposure" setting for a 1:1 mapping from RGB if you want. I added a lengthy section to my answer with an example, plus further caveats.

source: Stack Exchange

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

sort: votes


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Blender 3.3 Character Fbx Export - Error Uploading to Mixamo
Hello im using blender and Mixamo for character rigging and animation almost 2 years. But with last blender update's (3.3 - 3.3.1) Mixamo can't recognise models and rigged characters exported from blender. Not just solid meshes for Mixamo auto rig also previously rigged with mixamo characters don't recognise from mixamo.
macOS monterey 12.5 - Blender 3.3 - 3.3.1 Apple Silicon

I don't think your question is blender related. it's a problem in mixamo.

its perfectly works with blender 3.2 or earlier versions. but not 3.3

maybe try to ask Mixamo customer support why it doesn't work.

I have same problem, did you find any solution? Obj export works fine but not enough for me. When import fbx in 3ds max and again export as a fbx, mixamo is accepting that. Something wrong with Blender 3.3 fbx export, I couldnt figure it out.

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


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align the lines
I would like to align the lines. Is there any way to do this?

You could use project from view in UV editing, if that's what you mean.

have you tried to move the vertex of the UV in the UV Editor to correct it? Or unwrap again


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How do I fix this sharp edge?
I'm trying to use a loop tools bridge to connect the soles and the toes. But for some reason, there will be an edge than can't apply a subdivision modifier, how can I fix it?

hello could you please share your file? (at least this part of your object) https://blend-exchange.com/

Hi! thanks for your question. It looks like it could be an issue caused by irregular face normals, but any extra information you can give could help other users answer your question.

Looks like flipped normals. Have you checked the face orientation?

Well...check it, you guys are right. Face normals problem, already fixed. Thank you.


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Can I use Nvidia Cuda cores and NVLINK for EEVEE?
This question mainly pertains to Nvidias development within Blender. I currently have a 2080 and I know that Cycles ustilizes CUDA cores for rendering. However I plan on purchasing 2 3090's whenever they pop into the market and NVLINK'ing them for development reasons. My question is can CUDA cores and NVLINK be utilized for EEVEE's rendering AND viewport?


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how do I get the data panel?
Am using a more modern version of a tutorial I am following but the layout is different in it but I am trying to find the data panel which the mouse cursor is on from the older blender version tutorial: http://www.imagebam.com/image/16a7611354972651
this is my current part of that screen: http://www.imagebam.com/image/9d1aad1354972723
how can I find it please.

You first need to select an object if you want to see the Object Data tab

How to upload an image to a post


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how to get up the 'grid floor' options
Pls help me out with something I am trying to do with a character from Daz studio I've imported into Blender.
In the tutorial the person hits the 'N' button and this comes up (pictured here) http://www.imagebam.com/image/94216c1354935377 I do the same and I get the image in the second pic come up here: http://www.imagebam.com/image/97fe9d1354935425 in the same place because likely its a newer version.
What I'm tryin to do is change the grid floor selection to that in the first pic but cannot seem to find the appropriate screen for it when I hit 'N'. How can I do this please.

You can press the little down arrow for Overlays menu. This is in the up-right corner of your 3D-viewport.


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Eevee way much slower than Cycles
I've got a scene where Eevee viewport is so much slower that even makes my whole computer impossible to work with but when I change to Cycles it gets smooth like butter again.
Can anyone tell me what I'm doing wrong?
Thank you

A screenshot with default Eeevee settings is not really signifiant.. how is your scene?

My Scene has 6 characters exported from Daz3D as .obj
Some has hair, other doesn't just to make the scene a bit lighter.
And around 90 rocks not Instanced (will need to instance soon to get all work more smoothly).
it's..9,000,000 faces right now. I'm a noob with blender and didn't care about it till it started getting slow.
But my point is that, I thought eevee was quicker than cycles.
And now, while I can continue working with cycles, when I switch to Eevee it's impossible to even move the camera around.

Daz if often very high poly... that can be that (it depends on the concrete models you've imported).

Is it normal that eevee gets slower than cycles just because there are too many polys?

I have the same scene without the rocks, which is 3M faces only with the characters and it still too laggy to work with Eevee viewport. There must be something causing this.

I think it's more than likely your materials rather than your scene itself. I have had issues where using multiple Noise textures and other texture nodes within a material can really hurt performance on Eevee (I presume it pre-renders some surfaces to optimise the actual render - and this seems to cause a performance hit whenever the scene or materials are changed). Try removing your materials one at a time and see which (if any) is causing the lag.

This one makes much more sense to me. I've tried to slowly not removing but hiding the Eye on each materials. And I can see some makes it slower in just a second but once it starts to get slow ,even if I hide that texture again it's hard to get it back to smooth again and to try to find another texture that is could be ALSO responsible for the lag.

It’s likely that it’s your materials rather than your scene itself that’s causing the lag.
I have had issues in the past where using multiple Noise textures and other texture nodes within a material can really hurt performance on Eevee. This seems to be due to Eevee pre-rendering some surface textures to optimise the actual render - and this seems to cause a performance hit whenever the scene or materials are changed. Try removing your materials one at a time and see which (if any) is causing the lag. You may be able to simplify any materials that are proven to be causing the issue.

Update: I've recently made some more progress on this and tracked down slow Eevee performance to multi-dimensional Texture nodes in particular. For example, using a 3D texture (such as the default for Noise) where perhaps a 2D texture (Noise set to '2D') would do - for example, when using a UV map, the Noise (or other texture) should be set to '2D' to drastically improve performance.
Note that Eevee appears to pre-sample such textures and so reducing the Dimensions to the bare minimum for that case will drastically reduce the overhead (eg, it only needs to pre-sample a plane for a 2D texture instead of a volume for a 3D texture - the extra dimension is wasted processing time if that dimension is never actually going to be used).
Note that in extreme cases I have had Blender crash due to this - when I swapped from Cycles render view (which worked fine) to Material Preview mode (which uses Eevee regardless of your render settings). Reducing the dimensions often resolves the crash - as well as making the interface much more responsive.

What can I say? You are a 7uckng genius and lifesaver!


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Blender to maya
Recently I work for a client who works on maya. He likes my work, done in blender he want the project file in .mb . Is there any way I can transfer my project all the shading texturing export to maya without losing the quality? Yes I can covert the file with fbx or obj formate but when I do that the texture is not appear only white shading please help me with that. I research all day could not find any solution, For single model exporting to obj works fine but in my case I have multiple object with hair particle and cant export the texture and shading and this drive me nuts please help me!!!

https://blender.stackexchange.com/questions/18395/ https://blender.stackexchange.com/questions/57531

glTF may actually be a better option than fbx. In general the material nodes aren't portable to other software though and all exporters support at most a basic PBR setup with a single Principled BSDF and image textures.


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How to unhinge 2 objects?
I created a Thorus after a Plane.

Now somehow if i move the Thorus, the plane moves with it. I just guess it's because the Thorus shares the Plane's cursor/pivot point/3d cursor.
Why did this happen and how can i 'unhinge/unmerge' the objects?
It seems to me that the Thorus parented itself to the Plane. But that doesn't show in the Outliner Panel?
I would have made a small demo video demonstrating this, but i don't know how. I hope the screenshot snippet will suffice!
Thanks for reading!

It must be because you've enabled the Proportional Editing (blue sphere icon on the top)

Yes! Thank you! That was it!:-)


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How to retopology the model with out losing the detail?
I'm a beginner at blender and I try to retopology my sculpted model by using QuadRemesh. But the retopology model loses a lot of detail. I try to use shrinkwrap and multiresolution but it will make my model have a ton of triangles. It makes it hard to do texturing and rigging. Does any way can lower the triangles but keep as many as possible details?

You can first try a Ctrl E > Un-Subdivide, and check the values in the Operator box, you'll probably need to make some corrections though, if this doesn't work you'll probably need to retopologize manually, that's why you should always keep a low-poly version (if you began with a low-poly version of course)

The QuadRemesh is a good addon. It should have an adaptive remesh option so it adds more details where it is needed and less where it is not needed. But if this character is your main character and not a background character or one in a crowd then I would do a manual retopology to get proper edge loops. They are important for facial expressions. Blender Studio offers stylized base meshes for free.

Helpful videos about retopology: https://youtube.com/playlist?list=PLn3ukorJv4vs8PQj8z_PMbZAVLFEhQF5L and https://youtube.com/playlist?list=PLL3OEv6vd5VA4owAPOI0QdCcEmvl1f3BT. Blender Studio also has live streams about the creation of their character "Snow": https://www.youtube.com/watch?v=sXhIz-5g3Gc. Snow you can get here: https://studio.blender.org/characters/

If I gonna make an animation and two main characters in it. What is the limit of polygons/triangles for each character?

The limit is how many polygons your computer can handle ;-) Your goal is to have as few polygons as possible and to get the shape and details you want at the same time. A full-character model often has 20k to 30k vertices. You can bake normal maps for skin and cloth details. If you add a subdivision modifier with (1-2 levels) the model can have 100k or more vertices. But while you create the animation you can turn off the modifier to get the best performance in the viewport. This way you don't have to worry about the polycount. Keep in mind the environment also requires polys & they can sum up


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Proplems of generate rig
I'm trying to generate a rig for my character. But for some reason, the generated rig doesn't fit my setup metarig. Can anyone help me to fix it?

Both model and Metarig should have all transform applied (Ctrl A) before generating. Check if your metarig has coordinates 000, 000, 111.
Check Delta transforms also.


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How to Unwarp UV to a complex model
I'm a beginner at blender and I try to make a female character, but when I try to add some texture paint and adding hair for my character. It said missing UV, but I don't know how to Unwarp this character. Do I need to redo some parts of the process or missing some processes?

hello, it has nothing to do with your question but are you sure that you need such a dense mesh?

Select the mesh
Go into Edit Mode
Press  U
Press Smart UV Unwrap

This should uv unwrap the mesh for you.

Thank a lot. It help me so much.

Hello and welcome. This site is not a regular forum, the answer section is reserved exclusively for answering the OP question, to post comments or replies please use the comments section instead. Please don't reply "Thanks" as an answer or comment, instead upvote the post that helped you. If you feel it completely solved your issue consider marking it as accepted.


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About Eyes & Hair rigging problems
I'd try to do rigging for my character. But how to handle the eyes and hair? Should I join them to the main body and then do rig or what?

Let the eyes as a separated meshes.
You can create a main rig for your body, and on the bone you will set for the head, you can parent the eyes (so they will follow head moves). Once this is done, you will be able to create separated bones to control each of your eyes.
Here is a useful tutorial on how to set the eyes bones with an existing body rig.
https://www.youtube.com/watch?v=xSsav9wlDwI

Another solution than B.Pader's is to join the eyes and hair to the character object (CtrlJ), create 2 bones for the eyes, parent them to the head bone, and assign the eye meshes to 2 vertex groups that have the same name as the eye bones. For the hair, assign it to the vertex group that has the name of the bone that controls the head.


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How to make the stone pillar have a better light behaviour?
I'd try to make a scene with some stone pillars in it, but for some reason, it looks a bit different between the original file and the scene file.

the single pillar with sunlight and point light

The whole scene with a sky texture, sunlight, and compositing glare high/low and sunbeam
Should I add a Fill Light, rim light, or other things?

Hello and welcome.  What is your desired outcome?  What exactly displeases you about what you currently have?

I expect the outcome as the first picture, to look more realistic. The second one is kinda fake and looks like some paper.


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Why does a ball appear when I select a bone in pose mode
When I use plugin Mr Mannequins Tools, I find that when I click some bones in pose mode, a ball like a gizmo will appear like this

You can hide it by turning off Relationship Lines in Viewport Overlays, but I want to know what it is and how to add and delete it.
Thank you :)

"Mr Mannequins Tools" must be a third-party addon and questions about it are off topic here. Try asking on the web site that hosts it.

So this ball is unique to this plugin, and does it not exist in ordinary Blender?

Yes it is. Presumably the addon is accessing the code to draw it using python.

See Custom Shapes in the Blender manual.

OK, I try to reset the coustom shape, but only the bone have changed back, the ball is still there, maybe as you said, it was drawn with python. But anyway, thank you for your help

It looks like a limit rotation overlay ...
Limit set to full range ...

Limit set to 90°

wow, is this! thank you for your answer. It's very helpful to me


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How would I turn this 2D drawing into 3D in Blender?
I'm not super familiar with Blender, but I imagine that creating a 3D room based on this 2D sketch wouldn't be super difficult. Any suggestions?
Thanks
Lars

Use your image as reference image in top view, create a plane, merge at center to get one unique vertex, extrude on X, Y or diagonally in order to draw the shape:

Extrude on Z:

Create some edge loops where you're supposed to have doors or niches:

Then extrude and remove the useless faces:

Cut off the doos:

Give your object a Solidify modifier with the Even Thickness option enabled:


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Is it possible to use blender to create a curved surface based on an original formula instead of the one used to create NURBS?
The way curved surfaces are created by computers is, for each conceivable point on a rectilinear surface, a formula is applied which evaluates the position of control vertices to determine where in space that location on the surface should be. What I'm wondering is, if it's possible to use a unique formula to evaluate the vertices, there in producing a new form which could be drastically different than would be the NURBS surface produced by those same control vertices?

With geometry nodes maybe.

see this and that

Here's another one https://blender.stackexchange.com/questions/271833/how-to-render-y-x-1-y-x12-4y-1-2-2-in-blender


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Can Blender create a curved surface from vertices and a custom formula?
Is it possible to use blender to create a curved surface based on an original formula instead of the one used to create NURBS?
The way curved surfaces are created by computers is, for each conceivable point on a rectilinear surface, a formula is applied which evaluates the position of control vertices to determine where in space that location on the surface should be. What I'm wondering is, if it's possible to use a unique formula to evaluate the vertices, there in producing a new form which could be drastically different than would be the NURBS surface produced by those same control vertices?

Hello and welcome. Please don't post the same question more than once. If your previous question was put on hold, address the raised issues by editing it so it can be reopened rather than post a new one, otherwise see What should I do if no one answers my question?

see this and that

Here's another one https://blender.stackexchange.com/questions/271833/how-to-render-y-x-1-y-x12-4y-1-2-2-in-blender


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Modifying the Emission Strength of a material in Python
Linked to my previous question about the colour, I would like to modify the strength of the emission. I did something similar with the colour, but it's not working:
led = bpy.data.objects["LED"]
led.animation_data_clear()

led_mat = bpy.data.materials['LED_mat']
led_mat.use_nodes = True

tree = led_mat.node_tree
nodes = tree.nodes
led_emit = nodes.new("ShaderNodeEmission")
led_emit.inputs["Color"].default_value = (1.0, 1.0, 0, 1)
led_emit.inputs["Color"].keyframe_insert("default_value", frame=1)
led_emit.inputs["Strength"].default_value = 10
led_emit.inputs["Strength"].keyframe_insert("default_value", frame=1)
new_link = tree.links.new(nodes['Material Output'].inputs['Surface'], nodes['Emission'].outputs['Emission'])

The colour is modified, but the strength stays at 1.
Is there an additional parameter regarding the strength?

Several emission nodes, probably, replace the last line by "new_link = tree.links.new(nodes['Material Output'].inputs['Surface'], led_emit.outputs['Emission'])"

Thanks it worked! Another question: when I put the strength to 0 the material becomes black instead of not emitting light, is it normal?

Your script works but each time you run it, it creates a new emission node.
And as you are using nodes['Emission'].outputs['Emission'] to create the link, you always connect the first that have been created.
I suggest to define a function that will retreive the node if it already exists or create a new one if not. As in the code below.
import bpy

def get_or_create_node(nodes, type, class_name):
    # Find a previous node of type
    for node in nodes:
        if node.type == type:
            return node

    # if it does not exist create it
    return nodes.new(class_name)

led = bpy.data.objects["LED"]
led.animation_data_clear()

led_mat = bpy.data.materials['LED_mat']
led_mat.use_nodes = True

tree = led_mat.node_tree
nodes = tree.nodes

led_emit = get_or_create_node(nodes, "EMISSION", "ShaderNodeEmission")
output_material = get_or_create_node(nodes, "OUTPUT_MATERIAL", "ShaderNodeOutputMaterial")

led_emit.inputs["Color"].default_value = (1.0, 1.0, 0, 1)
led_emit.inputs["Color"].keyframe_insert("default_value", frame=1)
led_emit.inputs["Strength"].default_value = 2
led_emit.inputs["Strength"].keyframe_insert("default_value", frame=1)
new_link = tree.links.new(led_emit.outputs['Emission'], output_material.inputs['Surface'])

Concerning your second question (in the comments), yes this is normal for an emission node. When emission strength is set to 0, no strength, no light, so the objet is black.
If you want an object that keeps its color when not emitting light, use a principled bsdf node instead.
The code could be the following.
import bpy

def get_or_create_node(nodes, type, class_name):
    # Find a previous node of type
    for node in nodes:
        if node.type == type:
            return node

    # if it does not exist create it
    return nodes.new(class_name)

led = bpy.data.objects["LED"]
led.animation_data_clear()

led_mat = bpy.data.materials['LED_mat']
led_mat.use_nodes = True

tree = led_mat.node_tree
nodes = tree.nodes

led_emit = get_or_create_node(nodes, "BSDF_PRINCIPLED", "ShaderNodeBsdfPrincipled")
output_material = get_or_create_node(nodes, "OUTPUT_MATERIAL", "ShaderNodeOutputMaterial")

led_emit.inputs["Base Color"].default_value = (1.0, 1.0, 0, 1)
led_emit.inputs["Emission"].default_value = (1.0, 1.0, 0, 1)
led_emit.inputs["Emission Strength"].default_value = 0
new_link = tree.links.new(led_emit.outputs['BSDF'], output_material.inputs['Surface'])

Thank you, I used the last solution. The strength is changing (as well as the base colour), but the emission colour is keeping the same, should I address the colour node differently?

it depends on the result you want, you can effectively lower the emission color as well as the strength.

I mean, the colour is not changing, it is keeping green (the colour set manually before), even if I set another colour (at the initialisation like in my post that should be yellow, or later with a for loop)

@DarkPatate, what is your code, exactly?

for simplicity, please upload here a blend file showing the issue.

here is the link to the project: https://drive.google.com/file/d/11TqiizZ7_tFB3Qy0xbuV3tYahwbHKyVB/view?usp=sharing

The color does not change because a Color node is linked to the principled. This situation is not handled by the Python code : https://i.sstatic.net/08phw.png


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bisect mirror doesn't work
im trying to mirror bisect a mesh.
I used ctrl - and got a cutout I wanted in the first shape.
the applied mirror in the first ( cutted) shape.
the cutout doesn't happen on the other side.
if I toggle bisect on Y, it shows the mirror on the other side in wireframe , but not in viewport shading.
what is weird is that I have another project that I followed one tutorial in, and in that project , all works fine when I follow the same procedure..

thanks a lot in advance..

maybe your object is not correctly oriented, what does it give if you apply the rotation (Ctrl A)? If this is not the problem, please share your file


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Create a wire roll fall animation
I want to create a animation of a rolled wire falling form a 3 meter distance and be able to see how the wire falls and becomes tangled.
Sorry for my bad english
It would be a wire like in the next image

I would appreciate a lot your help since I didn't find any information

Hello and welcome. Please tell us what you have tried and where you got stuck

and a sample animation or a link to yt how it should look like would help as well. Animations can have a lot of variations and it is not clear how yours should look lke.

Are we to understand you want the wire to unroll, as it falls, or hold together, reasonably well?

If it's possible I want it to unroll but the important thing is once it bounces it will get tangled. 2. I couldn't find a video but what I'm trying to simulate is a bad packaging from a bongard, when they use the auto accumulate the rolled wire falls and gets tangled but if it's not enabled the wire rolls from the base of the container (https://youtu.be/rOwPAookusA) 3. I tried to generate a spiral and increase its depth but I can't use the rigid body to make it fall. To be honest I just started with Blender.


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Path following via API
Apologies if this question has been answered already, but I can't seem to get this thing working.
What I am trying to do is have a cube follow a curve interpolated out of coordinates. Manually this would be done selecting both curve and cube and selecting "follow path" constraint in the Ctrl + P menu.
I have have put together a short script, but when I run it, the curve has the cube as a child, and there is a follow curve constraint. But the cube is not centered on the curve, and pressing play will not do anything.
I believe that I might be missing something conceptual, but can't really figure out what that is.
Thanks!
import bpy

# Clearing scene
for item in bpy.data.objects:
    bpy.data.objects.remove(item)

# Simulation Parameters
coords = [[0,0,0],[0,5,0],[0,0,15],[15,0,15], [0,0,20]]

bpy.ops.mesh.primitive_cube_add()

# making curve
crv = bpy.data.curves.new('crv', 'CURVE')
crv.dimensions = '3D'

# initialize spline
spline = crv.splines.new(type='NURBS')

# a spline for each point
spline.points.add(len(coords)-1) # 1 point by default

# assign the point coordinates to the spline points
for p, new_co in zip(spline.points, coords):
    p.co = (new_co + [1.0]) # (add nurbs weight)

# make a new object with the curve
obj = bpy.data.objects.new('object_name', crv)
bpy.context.scene.collection.objects.link(obj)
obj.name = "Path"

# Constraining Space craft to orbit
cube = bpy.context.scene.objects['Cube']

#cube.parent = bpy.context.scene.objects['Path']
bpy.ops.object.parent_set(type='FOLLOW')

cube.constraints.new('FOLLOW_PATH')  #Constraining cubesat to follow the path
cube.constraints['Follow Path'].target=bpy.data.objects['Path']
cube.constraints["Follow Path"].forward_axis = 'FORWARD_X'
cube.constraints["Follow Path"].use_curve_follow = True
```

Some tweaks.
Took out the remove all objects, not a fan.
Use object references. After using an operator to add the cube
cube = context.object

after creating the curve obj it is known by reference as obj, no need to look it up as "Path".
When parenting via the operator, the selected objects are parented to the active. Have set the curve as active
context.view_layer.objects.active = obj

and selected the cube
cube.select_set(True)

before parenting via the operator.
Animate by setting an path duration (start to finish)  in frames on the curve object, and keyframing or driving the evaluation time.
See Creating path curve using python script  re using the end points of a nurbs curve
import bpy
context = bpy.context

# Clearing scene
# IMO never add this to a question script.
'''
for item in bpy.data.objects:
    bpy.data.objects.remove(item)
'''
# Simulation Parameters
coords = [[0,0,0],[ 0,5,0], [0,0,15],[15,0,15], [0,0,20]]

bpy.ops.mesh.primitive_cube_add(location=coords[0])
cube = context.object
# making curve
crv = bpy.data.curves.new('crv', 'CURVE')
crv.dimensions = '3D'

# Animate the eval time (keyframes)
crv.path_duration = 250
crv.eval_time = 0
crv.keyframe_insert("eval_time", frame=1)
crv.eval_time = 10
crv.keyframe_insert("eval_time", frame=100)
crv.eval_time = 250
crv.keyframe_insert("eval_time", frame=250)
# initialize spline
spline = crv.splines.new(type='NURBS')
spline.use_endpoint_u = True
spline.use_endpoint_v = True
# a spline for each point
spline.points.add(len(coords)-1) # 1 point by default

# assign the point coordinates to the spline points
for p, new_co in zip(spline.points, coords):
    p.co = (new_co + [1.0]) # (add nurbs weight)

# make a new object with the curve
obj = bpy.data.objects.new('Path', crv)
context.scene.collection.objects.link(obj)
obj.select_set(True)
context.view_layer.objects.active = obj
cube.select_set(True)
#cube.parent = bpy.context.scene.objects['Path']
bpy.ops.object.parent_set(type='FOLLOW')

'''
cube.constraints.new('FOLLOW_PATH')  #Constraining cubesat to follow the path
cube.constraints['Follow Path'].target = obj
cube.constraints["Follow Path"].forward_axis = 'FORWARD_X'
cube.constraints["Follow Path"].use_curve_follow = True
'''

Fixed Position.
Generally a user of fixed position and no follow path parenting. As shown in answer here https://blender.stackexchange.com/a/169719/15543  With fixed position can keyframe or drive the offset, such that 0 is start of curve, and 1 is other end.

Thank you very much! And sorry for leaving the delete all objects line.


text:
Can you control intensity of AO baking effect on specific material for object A, while baking AO map for Object B which is influenced by A?
You have object B on which you bake AO map, object A should influence it, but I would like some surfaces of object A to have less/more impact than others.
I know I can separete surfaces to different object and set that object to be ignored for baking, but that would make them completly be ignored, which is not what I would like to achieve.
Or maybe alternatively is there a way to control how much AO effect can object A have while baking AO map on object B?

If you're prepared to use OSL (and therefore CPU), this is a first shot at variable AO-influence.
It's a hack of François Gastaldo's AO shader, found among Sambler's collection.
Having declared matIdx earlier, it makes the following change, which multiplies the factor of the mix between background color and AO color, according to the Pass Index of the material struck by the AO probe ray.

In the following illustration, the white box is directly shaded by the script.The red cubes have materials with indices 0,32,64,128, and 200:

There are a couple of simpler AO scripts in the collection that could serve instead, and you might want to refine the exact effect. But this could be a starting-point.

nice! exactly what I was hoping exists, thank you

I have been experimenting with that and I can get material to behave how I like for render, but how do I use that for baking AO map, no matter what I do baked results is always the same and ignores any custom osl scripts in materials

Hi, @robert  ! .. fine, at my end. Are you by any chance baking AO? That would be the internal AO, not ours.  Here, the tree is plugged straight into the Material Output, as in the upload, and the Emission is baked.

Oh thank you, that makes sense.


text:
Particles stop emitting too early (bug?)
I am pretty new to Blender.
I have a cube that is suppose to emit particles over a course of ~1000 frames. But the whole number over particles gets emitted in the first frame. This happens without the influence of turbulence fields, since I turned them Off for my cube via field weight settings/effector collection.
I have two Bevel modifiers chained before my particle system but it doesn't seem to make a difference for the emitting problem (other than turning on use modifier stack).
The reason I think it might be a bug is that sometimes when I switch settings - for example switching emit source from faces to vertices - I get the normal result of slowly emitting particles. However even then the cube stops emitting after ~200 frames instead of 1000.

before emitting start frame 700

after emitting start frame 733 (cube is moving downwards)

Hello could you please share your file? https://blend-exchange.com/

did u ever delete your cache?

I have tried this and it seems to work for me.  I don't see any bevel results in your screencap.  Perhaps these setting are too fine?
Here from my experiment frame 1:

and frame 14, as the particles stop emitting from the system.  I see that all faces of the bevel'd object are being used.

for comparison:

In the end I implemented a workaround, using a seperate object as an emitter for the particles and placing it inside my cube.


text:
Automatic Weight fails totally
I have this model here and it is symmetrical.
I removed doubles, I recalculated the normals, I fixed non-manifolds, I removed existing vertex groups. But still, when I try to parent my mesh to the rig it fails. What could be the issue here?
My .blend file

Hello, please [edit] your question and add images. Your question should not rely on downloading a file. In the future, please use Blend-Exchange to upload blend files. Thanks :)

It looks like parenting high-poly meshes fails, I don't know why, but if you merge by distance with a value of 0.0005 it won't be noticeable and it will parent correctly (and anyway you should work with a much less polygon version)

The issue is around/in eyes and mouth. Don't know why either. In these parts: https://i.sstatic.net/Nv7xT.png

Thank you moonboots, it is working well now!

It looks like parenting high-poly meshes fails, I don't know why, but if you merge by distance with a value of 0.0005 it won't be noticeable and it will parent correctly (and anyway you should work with a much less polygon version)


text:
Corner of the room is a little bit lighter and shinier
I am making my first scene in blender and I can’t figure out the render setting of EEVEE.
The main issue I can see in my render is in the corner of the room, where the corner gets little bit lighter and shinier. How can I fix that? Any other tips on improving my render would be very much appreciated.
Picture of my render settings and wall material.

Geometry issue, maybe. Can you add a wireframe screenshot?

Yes! I added the wireframe i the question.

In your shader setup the Image Texture nodes for the Normal Map and the Bump Map should have the Colorspace set to Non-Color, not to Filmic Log.
The Eevee settings look good. Maybe activate Contact Shadow in the settings of the light if you haven't yet.
To make the scene more "real" play with the lights. Where comes the light from? Is there a window? Is it dark outside and there is a table lamp? Try an HDRI for the world background.
Make the car metallic and reduce the Roughness value. If the table and books have no Roughness maps then you can add a Noise Texture node with high scaling to the Roughness. This will make them look less "clean" and "flat" (It's hard to tell from the screenshots if you have already done this)

I have contact shadows on in all the lights. It is meant to be a basement and a dark room without windows. None of that solves my problem of lighter corners but the noise texture made the table look little bit better thanks!


text:
Realistic deep water shader
How would you go about creating a realistic deep water shader to depict a scene such as this one from blue planet II? I tried with a volume scatterer but had mixed results. Ideally it would be amazing to tie the shader to the water's depth, thus simulating everything from shallow waters, twilight zone, and the deep.

Hello :). This is practically just dense volumetrics. Principled Volume is all you need. Unfortunately, Cycles isn't very good at rendering volumetrics, so you'll get a lot of noise.

Thanks! Any advice on how to increase the rendering's quality?

Hey :). High samples with a Denoiser, there's no magic button. Last time I rendered such a scene I used 15 000+ samples.

Or you could use Eevee, but you'll need to render at double resolution to get it pixel perfect. Unfortunately, Eevee is also more finicky than Cycles.

All you need is the Principled Volume shader.

Create a volumetric cube
Give the volume a very light color, and use Density to control it
Use real units for light intensity (lumens). Related answer: Simulating a 40W Light Bulb.

Lights: 10 million lumens (a really strong searchlight), Density: 0.1, Samples: 2000 + Denoiser

Adding a tiny bit of displacement in comp might help as well.


text:
Getting NURBS in and out of Blender
Is there a working way to get NURBS curves into and out of Blender?
FBX supports this, but when I import an FBX with NURBS, the curve is not created.  I've tried with several versions.  FBXes exported with blender do not contain correct curve data.
OBJ export appears to work, but when I re-import them, the curve paramaterisation does not match what was exported.
IGES support doesn't appear to be available in the list of plugins, either.

I tried with OBJ. I managed to export a curve as NURBS (although knots seem way off), but surfaces are just transformed into meshes before exporting. Import adds just a bunch of vertices without any surface. Tried both legacy and new Wavefront importer/exporter with the same result.

For export, this is the best I found: https://www.digital-sculptors.com/cms/index.php/software/blender-plugins/63-export-iges.html
SubD will be exported as patches in an IGES file that can be made into a solid if the subdivision surface mesh was manifold.
For import I do not know a good way, please upvote this features request and comment on it: https://blender.community/c/rightclickselect/v8g8/


text:
Particles fail when using Animation Nodes?
I have the goal of trying to instantiate objects that emit particles, and have the new objects follow points on other objects.
My approach has been to attempt to use Animation Nodes. However, the add-on seems broken? I am following a few tutorials such as this one: https://www.youtube.com/watch?v=S3uschDguJk
As you can see, the basic idea is to instance an object with a particle emitter onto vertices of an animated object (or several). The instancing part works, but in Blender 2.8 and 2.9, the particles do not emit properly once the Object Output Transforms is used to actually move the instance objects onto the vertices. They do not move at all, and lose all interaction with physics or fields.

As you can see, the original emits particles with physics interaction, but the instanced objects (while generating particles) have them remaining stationary on the surface (and following along with the object animation).
In the above youtube video the behaviour is different.
I have also attempted setting location with the attribute node, but (once again) the actual placement of the objects work, but the particles lose any physics
Any advice regarding how to fix this - or alternatives? Many thanks in advance!

a blind file would help...

You can bake object transformation into keyframes using Set Keyframes node. It should work.
If you don't want to bake animation then try this method:
Step 1: Create empty objects using Object Instancer and do whatever animations you want to those empty objects.
Step 2: Create instances of actual object having particles using Object Instancer. Then unlink it from node. You can do that by pressing Unlink Instances From Node. which can be found on advanced settings of Object Instancer node. Then move those objects into another collection.

Step 3. Get objects from collection using Collection Info node. Then set empties as parent for these objects using Attribute Output node.

Thanks! That works well.
However, why are these extra steps needed? The old way was much more elegant where the object transform would be set and particles still behaved independently?

I'm not sure why it don't work may be because AN is updating object data on every execution. Between my answer need a correction, you need to put objects into a new collection after unlinking from node.

Another workaround is to union the result(s) to a fixed object. My AN-generated rockets weren't emitting exhaust right (particles reset on every frame and hugged the rockets).
I added a boolean to an empty mesh, assigned it to read the whole collection that AN outputted, and then the particles behaved more as expected. (Still no subframe particle emission positions, though)


text:
How can I get this mesh to stop distorting on import?
I have a robot character with armature and animation, and it displays correctly in Noesis:

The armature is shown in red, and I've selected a specific bone named Dummy010, shown in red/blue/yellow at the bottom left of the image.  Everything seems to be working just fine until I import the character into Blender:

The same bone, Dummy010, is highlighted at the left edge of that image, but as you can see, the same thing is happening to all four legs.  I'm using an add-on called Better FBX Importer/Exporter, but the same thing happens with the regular FBX importer.
Here's my .blend file:
robot .blend file
How can I get this distortion to stop happening?

Check if the bones are at their zero pose position in both cases.

Could you check where is the origin of the armature compared to the origin of the mesh BEFORE export ? It seems that the mesh is shifted in Blender, the main bone not being right under the legs platform, as in Neosis.

It's easy to fix:

Select the armature and switch to Pose Mode
Press A to select all bones
Pose > Clear Transform > All

Please stop rolling back changes when we are applying the proper formatting on this site.


text:
How can I procedurally modify this texture to make it look right?
I have a texture extracted from an online source.  It's the face texture for a human character, with hair and beard included.  For clarity's sake, the hair portion is in the lower right, the beard portion is in the upper left, and the upper right portion is for hair planes.  This image is a PNG, and so a lot of the white space you see is actually transparency.  I'm using this texture, and the model to which it belongs, in Blender.
I can get the transparency for this character to work, but the basic color is off.  This character should have dark brown hair, but as you can see in the image, it is initially colored blue and green.  I can usually fiddle with it enough for it to approximate the correct hair color, but I've got a lot of these type of files and I'm hoping there is some procedural fix that I could apply to every texture I extract so I won't have to make my best guess.  I've tried fiddling with image adjustments in Photoshop, but I can't seem to figure it out.
Is there a single-click, or few-clicks, solution that would translate the colors in this texture into the correct colors?

The hair looks like a normal map

I agree, but there are separate normal maps, and this seems to be the only base texture map.

I think the way the color varies it'd be hard to apply one transformation to it to get the result you want.

What do the areas to be corrected have in common? Are they all the same color-range, in the same place, or whatever?

That's partly what I'm trying to figure out.  All the figures I get from this source have the same problem; the hair sections are discolored.  All other body parts are textured just fine, in both the diffuse and normal texture maps.  It's just the hair sections that are discolored.


text:
How do I get Blender to save Specular and other settings when exporting FBXes?
I have been working on a set of models that I want to export as FBX.  The default Specular setting seems to be 0.5, which gives a fake, plastic look to the models.  Normally I set the specular to 0.1, but when I export the FBX, Blender always resets the setting to 0.5.  How do I get Blender to retain my settings when I export?

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

Does this answer your question? .fbx export why there are no materials or textures?

Not quite.  The diffuse and normal textures stay attached, but the texture that's plugged into the alpha channel doesn't, and it resets Metallic, Specular, and Roughness.  I've tested this by exporting an FBX and re-importing it back into Blender.  Not sure why Blender won't save the figure exactly as it is.


text:
How do I separate joined meshes for texturing
I'm going to try to describe my problem, but I may have some of the terminology wrong.  I have a figure in FBX format that is made up of four separate meshes joined together to create a combined figure.  Parts A, B, C, and D should have texture sets A, B, C, and D, respectively, but when I load the FBX in Blender, texture set D is applied to all parts.
In object mode, the figure is animated, and all four parts are separated, which makes it easy to figure out which vertex groups belong to each mesh.  The problem is that when I go into Edit mode, all four parts are joined together, which makes it difficult to separate them so I can apply the correct textures.  What is an efficient way to deal with this, so I'm not selecting individual faces one by one?

I don't think they should be together in edit mode if they're separate in Object mode. Are you sure you don't have them all selected before going into edit mode?

As Agnivesh says, use L to select each separate mesh, and assign a different material to each mesh so that you'll be able to give them a different texture

Hover your mouse over a single mesh part and L that should select a loose/detached mesh.

That works if you know which body parts belong to which mesh.  In Object mode, the various meshes come together to form one figure or separate, depending on where they are in the animation.  It's easy to see which vertex groups belong to which of the four meshes when they're separated like that, but you can't select their vertices when they're in Object mode, or so it seems.  When I switch to Edit mode, the skeleton reverts to Rest Position, and all four parts are intertwined with each other.


text:
Keyframes are not moving
I have downloaded a walking animation, I want the animation to start after some frames like after 10 frames because I want the cloth simulation to be stabilized before the walking animation starts. I tried to drag the keyframes forward to play after frame 10 but the animation still starts from frame 1. The default animation length is 120 frames no matter how much I drag the keyframes it still starts from frame 1 and ends at frame 120. I opened the summary in the timeline, and the animation data added more keyframes in between when I moved the keyframes but after frame 120 the keyframes seemed to be empty.

May be because your end frame is only set to 120 frames. Try adjusting it to a higher number.

I've already tried that still doesn't works.

So you are unable to move the keyframes even if your end frame extends beyond 120 frames?

Yes the animation still starts from frame 0 even if I extends the end frame beyond 120 frames I guess there is something locked in the animation data.

That's really weird. So you can't move the keyframes at all away from the beginning of the timeline?

No, I can't able to drag those frames.

Is there any chance the keyframes are locked? I know the screenshot doesn't show that, but what about sub-categories inside the character layers?


text:
Objects seperating in 3d print
I have created an object in blender, copied it, mirrored it and put them together to create one object.
The random thing is that when 3D printing the Stl file, it's seperating the 'original' half into its initial sections (objects) it was created from. Yet the copied half prints fine.
Totally confused, and help is appreciated.

Could it be that you have to merge nodes to make a single object of all the "initial sections"? Joining two objects does not merge vertices, edges and faces.

Can you upload your .blend through Blender Exchange?


text:
What is the fastest way to texture all of these keys?
For an school project I have to make 5 products full textured and detailed.
Since it doesn't have to be game optimized I choose for individual keys on the laptop.
Having to texture them all 1 by 1 will take very very long.

So my question is: "What would be a faster way to do this?"
Edit: (Forgot img)

Hello, do you need one texture per key, or all have the same texture, and do you need to put the letter on each key?

@moonboots All keys different letter. same texture.

Possibly related (at least, for the letter-keys) https://blender.stackexchange.com/a/287715/35559

You could unwrap all the top faces apart from the rest (with the Project from View mode, once done invert the selection, unwrap and put the rest of the UVs over a transparent part of your image), and place the UVs on a picture with all the letters on a transparent background, mix the Image Texture with a background color in a Color > Mix Color node, and maybe add a bit of bump?


text:
Trying to get neighboring vertices
Here is my current approach. I am probably misusing the "Edges of vertex" node.
Anyway I don't really know how to solve this problem.
My current solution works if the vertex Id is a constant number that has been inputted by the user, but for my use I need it to be able to use an id that has been acquired by any mean that is similar to the approach I chosen or really any approach.
Yes I am aware I could skip the first few nodes and just plug the vertex Id in, but that wouldn't be actually usable for anything beyond that.
From my observations it doesn't work, because the vertex id(vertex in the repeat zone) is using the index node and when used in the selection it basically only works for the vertex id (64), I was trying to find a way around it, but I was unsuccessful.
If there is a way to get neighboring vertices then I will appreciate it if you would be so kind to share this method.
Thanks for reading all of this, I am not good at explaining stuff.

Does this help
https://blender.stackexchange.com/questions/269127/geometry-nodes-get-the-neighboring-vertices-of-endpoint-vertices

Can you say how you want to use  your neighbouring vertices? That would clarify the overall problem a lot.

what are you trying to get? the index of the neighbors? if so you are not outputs any index, you are just keeping the vertex index and and iteration ID. you are storing a boolean temp value; What is what? what are you checking for and what are you trying to get?

your setup doesn’t really maks sense (at least for what your question is)


text:
How to get realtime reflections from motion tracked video?
I wanted to know if there is a way to get realtime reflections from a video, like if I have a motion tracked shot of a balloon festival; Naturally this will have a lot of moving colors so it isn't as simple as having a static HDRI.
Say I have a glossy reflective ball centered on my motion tracked shot set to a video of many people releasing colorful balloons, will it reflect the video or do I need some sort of dynamic HDRI? Is that even possible?
Or do I have to project the video onto a plane and have the sphere reflect that?
Is there any way to do these types of reflections? Thanks

What did you mean realtime? Is rendering things from a filmed video clip count toward it? It will be a big difference between static clip and live streaming video input.

Yes a static clip, nothing streamed. How to get the reflections from the video onto a reflective object on my scene but taking into account the fact that the object is motion tracked onto the video scene. Is something like that even possible?


text:
How to enable freestyle edges on top of freestyle faces?
Using blender render and freestyle lines I used "control- e" to set some freestyle edges to render, they render fine and all, however the mesh is animated and moves so it sometimes also renders freestyle lines set by the "edge types" under "freestyle line set" in "render layers".
I dont want these automatic lines in some spots so that is where "control-f" freestyle faces come in so that no lines render on those faces. The problem is that it also cancels out the freestyle edges I set with "control-e" and they dont render.
Is there a way to set freestyle faces and freestyle edges so that the edges I set render, while the freestyle face blocks the automatic lines at the same time?

I'm not sure to get it perfectly, but you can set freestyle to only render edges specified as "freestyle edge", like this

if you use face marks (here in blue)

you can use it to (eg) exclude some parts of the previously marked edges (also blue to make them more visible):

Right I get that part, but the problem is I want to enable silhoutte, border, contour, etc. and then block out specific areas where I dont want to enable that. For example if I have two blocks and on one of them, everything is enabled but for the other only edge marks are enabled. Which is why I tried to do edge marks on top of face marks (to disable the other options and only leave edge marks to render).

It's too complicated to understand just with words, I fear:try to create a small test case, easy to understand and share it here through http://blend-exchange.giantcowfilms.com/, then insert the provided link editing your question, and also add an image of what is wrong when you try the setup as in the file...

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


text:
Why does Mesh Deform modifier stop animating after a number of frames?
Im animating a jump cycle on a character and in order to circumvent cloth physics on a high poly mesh (for things like hair), im using cloth physics on a low poly mesh and then using a Mesh Deform modifier to bind that to the parts I want to obey physics. It works beautifully but only up to about 200 frames, after those frames, those low poly meshes with the cloth physics stop following the armature, they stop wherever they are in the world space and then because they are bound to the mesh create these stretched out meshes as the character moves.
They are properly parented to the armature, bound to the mesh, and it works fine up until those frames. Is this a hardware limitation on my end, or is there some setting I can change?

I expect the clothe cache end frame needs to be increased.

wow, beautiful, such a simple resolve to the huge problem I was having, Thanks again!

user sambler answered my question -
"I expect the clothe cache end frame needs to be increased"

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


text:
Getting mouse position relative to movie clip
In the clip editor, I need to find out the position of the mouse relative to the current movie clip. I know I can get the mouse position with event.mouse_x and event.mouse_y in my modal operator. I can also use context.region.view2d.region_to_view to get the mouse position relative to the view.
However, none of these tell me where the mouse is relative to the movie clip. Ideally (0,0) would be one corner of the movie clip and (1,1) the opposite corner. How can I find out the mouse position?

If you run this script in Blender's text editor, you can press L with your mouse in the preview window to get the position of the mouse in pixels relative to the bottom left corner of the video clip.
import bpy

bl_info = {"name": "Mouse Pos", "category": "Sequencer"}

class GetMousePos(bpy.types.Operator):
    bl_idname = "mouse_pos.get_mouse_pos"
    bl_label = "Get Mouse Pos"

    def invoke(self, context, event):
        # Size of the preview region
        width = context.region.width
        height = context.region.height

        fac = 1.0

        prs = bpy.context.space_data.proxy_render_size
        res_perc = bpy.context.scene.render.resolution_percentage

        if prs == 'SCENE':
            fac = res_perc / 100

        rv1 = context.region.view2d.region_to_view(0, 0)
        rv2 = context.region.view2d.region_to_view(width, height)

        preview_zoom = (width / (rv2[0] - rv1[0]))

        # Resolution of the scene
        res_x = context.scene.render.resolution_x
        res_y = context.scene.render.resolution_y

        # Distance of video preview from bottom left corner
        offset_x = -int((rv1[0] + ((res_x * fac) / 2)) * preview_zoom)
        offset_y = -int((rv1[1] + ((res_y * fac) / 2)) * preview_zoom)

        print(event.mouse_region_x - offset_x, event.mouse_region_y - offset_y)

        return {'FINISHED'}

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

    keyconfig = bpy.context.window_manager.keyconfigs['Blender Addon']
    km = keyconfig.keymaps["SequencerPreview"]

    kmi = km.keymap_items.new("mouse_pos.get_mouse_pos", 'L', 'PRESS')

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

    keyconfig = bpy.context.window_manager.keyconfigs['Blender Addon']
    km = keyconfig.keymaps["SequencerPreview"]
    for kmi in km.keymap_items:
        if kmi.idname == "mouse_pos.get_mouse_pos":
            km.keymap_items.remove(kmi)

    bpy.utils.unregister_module(__name__)

register()


text:
Start blender in video editing mode & script setup
I am using powershell to install blender on an EC2 instance.  I would like it to default to video editing and configure the properties for the project via automation (powershell if possible).  I would like to set video output to 720p, fps to 30, etc.
Is there a way to automate the configuration?

I would simply prepare a startup.blend set as you want and replace the default one after installation/deploy

I have noticed that the path ...\Blender\2.79\config does not exist unless you have saved a user preference file.   This requires me to find the version of blender and create the directory with that specific version.  Is this the only way to get it to load this startup file for a first run of blender?

related: https://blender.stackexchange.com/questions/78121/can-i-change-default-folder-to-save-startup-file-startup-blend-and-userpref-ble


text:
Why on surface appeared line after using extrude
After I used extrude as you can see the surface appeared this lines, how can I solve this problem?
Thank you

Hello maybe a simple Auto Smooth will fix the problem, or could you please the object with the problem? https://blend-exchange.com/


text:
Create Seamless Fractures off a mesh
I require a quick workflow to create Seamless fractures. The Default Cell-Fracture addon doesn't seem to allow for that...

Steps to Reproduce

Create new Scene in blender
if not already enable Cell Fracture addon
select Cube -> F3 -> Cell Fracture
in settings set margin to 0 and apply
Go into Material Preview and seach for visible seams between the fractures

Geometry Nodes: Mesh Boolean / Mesh Splitting Repeat Loop

The problem isn't just with CF (although it has a problem as well, it's getting some precision problems and not handling them well.)  The main problem is with the Eevee renderer, used for material view, which seems to have an issue with seeing around edges when it comes to world lighting.

Eevee ain't the problem because with the solution proposed form Markus, can do seamless fractures which are not visible in Eevee, thanks Markus!


text:
Can someone explain how to cut a circle out of this circle?
I have this circle:

And i'm trying to cut another circle out of the center of it, roughly in a shape like this:

I've looked all over the internet, but I couldn't find anything. The only tutorial I could find about this was made in 2013, so it was a much earlier version of Blender that I couldn't follow along with. I started using Blender yesterday. Any help is greatly appreciated, thank you!

https://blender.stackexchange.com/questions/46342/is-there-a-way-to-fill-the-area-between-two-circles/46351#46351

you can inset your selection (i), scale on the X axis to make the inner circle oval, then select the oval face and press X > Delete Only Face

@moonboots Got it! Thanks you so much!

didnt you try to select the top side vertices of the cylinder while in edit mode then do copy and then scale it to the size you want using the S Key

Select the object that will be the "hole" in the 2nd object,

Shift + select the target object.

Tab to enter edit mode

Numpad 7 to go to top view (the cut will be projected so the view is important).

Enter edit mode with both selected, go to mesh, knife project.

Then just remove the resulting face.


text:
How can I separate or split a single mesh into two meshes?
How can I separate or split a single mesh into two meshes? Once I have two separate meshes would it be possible to make one be “shade smooth” and the other “shade flat”?
I am modeling a vehicle in blender using one mesh to make the shape of the car as a whole, however I find that the back of the car looks better when shaded flat as opposed to the front which looks better shaded smooth. Therefore I want to have the back as shaded flat and the front shaded smooth. My idea was to split the mesh in two and adjust each mesh in the way I wanted. If so how would I do this, and if this isn’t the way then how could I achieve the end goal I have in mind. Two parts of the single mesh shaded differently (flat and smooth).

Enter edit.  Select the faces that you want to separate.  'p' (separate) -> selection.  It's an okay thing to do, but better would be to use sharp edge markings (select edges of bits you want flat shaded, "mark sharp" operation.)

Hey :). Shading is set per face so simply select the faces and go Face > Shade Flat. No need to separate anything.

How can I select single faces in object mode then? Or am I meant to do this in edit mode, and therefore should I select all the faces of the part I want shaded flat.

@MateoL Yes, I meant in Edit mode :).

@Jachym Michal so I select the faces and then do go Face > shade flat, I am puzzled as I cannot seem to find where to do this. : (


text:
Why do parts of my model look really bad when I shade smooth? And how can I fix this?
Why do parts of my model look really bad when I shade smooth? And how can I fix this?
When I shade smooth parts of my model look pretty good and others look quite bad (I don't mean the shape I mean the texture). It can be seen in my model below where the part highlighted looks good and the one highlighted in red doesn't, how could I make the red part look and have the same texture as the green part.

Correct shading in blender is heavily topology dependent - blender favors quad based topology and often gives shading artifacts when attempting to smooth shade tri's and n-gon's. Make sure your mesh is made mostly (if not all) of quads (especially near curved edges), and that sections have the necessary supporting geometry.

Do you have Auto Smooth turned on in Object Data Properties?

I'm not sure, I think I just did shade smooth in object mode for the whole mesh.


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Model has a hole in it due to weird geometry in wireframe mode?
I'm fairly new to blender and have encountered a problem with wireframe mode. The screenshots show a hole that is visible in object mode but not in edit mode. I turned on wireframe mode to see the geometry and as you can see from the images it looks strange in this area. Any ideas how to get my mesh looking normal?
Screenshots-

Blend file-
Apologies if the answer is obvious, i've been trying to figure it out myself but have got nowhere. I've tried:
-Deleting loose vertices
-Merging by distance (removing double vertices)
-seeing if any ngons or tris in the area (there are none)
-Moving the vertices in the area around (nothing changes)
-Googling wireframe mode to learn about this mode and how geometry is generated because If I knew how it generated the geometry maybe i could fix it (couldn't really find much relevant info)

You've created a shapekey and it is selected, so whenever you try to bring some corrections in Edit mode it changes this shapekey, not the base shapekey, and as soon as you come back to Object mode, you don't see what you've done on this second shapekey, as its value is at 0, you only see the base shapekey, which remains unchanged. So you need to select the base shapekey and work on it, you can even delete this second shapekey if it's not useful.

Thank you, I was following a tutorial and didn't realise this problem was anything to do with the shape keys-thanks again

This has happened to me, but I'm not able to reproduce it right now.
These vertices are not perfectly on the axis, so the mirroring is duplicating them over very close to the axis.
An interaction with subdivision surface is creating this pinch.
You should be able to select the problem verts and use the N panel to set their positions exactly to the axis and eliminate this extra geometry.  You may then have to run a merge operation depending on what exactly is happening.


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Change the style of the "Attribute Text" shown by Viewer node
Sometimes I find it hard to read the text shown in the 3D Viewport by the Viewer geometry node (based on enabling the Attribute Text setting in the Viewport Overlay menu).

How can I change the color of this text, the color of the outline, the size of the text?

This isn't an answer, but I notice the contrast is a bit better so it's more readable sometimes if I uncheck Viewport Overlays -> Viewer Node -> Color Opacity (or set it to a low value), and maybe Viewport Shading > Lighting > MatCap > check_normal+y.exr (the colorful one).  https://i.sstatic.net/2UrD8QM6.png This is almost always necessary iwhen viewing an Index attribute, for which almost all values are >=1 (white), but sometimes it's not necessary for other attributes which have values between 0 and 1, for which the Viewer's coloring sometimes has good contrast with the text by luck.

Text attributes are controlled by the following theme settings:

Fill Color: view_3d.space.text_hi; in Preferences as:
Themes ▸ 3D Viewport ▸ Theme Space ▸ Text Highlight
Outline Color: view_3d.space.gradients.high_gradient; in Preferences as:
Themes ▸ 3D Viewport ▸ Theme Space ▸ Gradient Colors ▸ Gradient High/Off
Font Size: (cannot find API for this); in Preferences as:
Themes ▸ Text Style ▸ Widget Label ▸ Points

Note that you probably only want to adjust the fill color of the text; the outline color is shared with the 3D Viewport's background, and the font size is shared with various other UI elements throughout the interface:

To change the fill color with script, you can do:
bpy.context.preferences.themes[0].view_3d.space.text_hi[:] = (1, 0, 1) # magenta

This answer current as of Blender 4.2.1

Are you sure this is current?  In 4.2.3 (the same as 4.2.1, I would hope), I am trying changing the value of "Themes ▸ Text Style ▸ Widget Label ▸ Points" as you suggest; it is changing the size of various text (including the text in the very preferences panel in which I'm interacting-- fun!)  but unfortunately it is not changing the Viewer Attribute Text size which is what I want to make bigger.


text:
Creating a texture with random overlapping circles of different colors
I want to procedurally create a texture like the following, made of randomly-placed circles, all the same radius, with random grayscale colors applied. Ideally repeating (this one isn't). Ideally, NOT anti-aliased. Is it possible?

The little experimentation I've done is to create a white texture with circular alpha (setting alpha to Channel Packed, so the RGB channels aren't tainted), and mix that white color down to black based on a factor. I can modify the UV coords for a single image to scale it down and place it. And I can composite two RGBA images in a layered fashion.

What I'm missing is:

How to calculate multiple random numbers in a shader
How to make n copies of an image in a shader, and layer their results

https://blender.stackexchange.com/questions/102692/randomly-populating-procedural-shape-or-image-texture-in-cycles

@DuarteFarrajotaRamos Thank you for that. Seems at first like a slam-dunk duplicate. Unfortunately, the accepted answer no longer works (and has a 404 link to background info, and relies on an abandoned add-on), and the second answer appears—and I'm only a few minutes into looking into it—to produce black/white only (a single mask). But, the concepts of generating random numbers via noise are spot on, and hopefully more will be applicable, too.


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Union/merge overlapping coplanar mesh faces
After converting a beveled curve to a mesh, I have many instances of coplanar faces that overlap each other. How can I perform the equivalent of a Union in Illustrator, simplifying the geometry so no faces overlap?

This answer works some of the time, but requires manual intervention:

Select the mesh with the overlapping coplanar faces.

Enter Edit mode (tab).

Select all vertices (a).

In the top right of the viewport, enable "Auto Merge Vertices", enable "Split Edges & Faces" in the Options dropdown, and set the Threshold to the highest value you can accept.

Nudge the selection without actually moving it (g y 0 Enter).

This will merge most of the faces...

...but in some cases it may leave either overlapping faces or (worse) holes in your surface.

Where this happens you can manually select the problematic region and use Mesh > Clean Up > Merge By Distance and play with the value until you get a good planar result:

Not a good answer, but: you can

Convert the curve to Grease Pencil
Export as SVG
Open in Adobe Illustrator
Stroke to desired width
Outline stroke to create new paths
Save as SVG
Re-import to Blender as Grease Pencil
Convert Grease Pencil to Poly Curve (Bezier curves have fill problems with certain hole configurations)
Set curve to 2D (after rotating to XY plane), and enable fill:both
Manually select inside and outside loops and press F to fix the inside/outside fills

Now you have a curve that's the same shape, without overlapping pieces, and you can convert this to a Mesh if you desire. (Or, if you're using it for a knife project as I was, you can use the curve directly.)
I won't accept this as the answer as it requires an outside tool like Adobe Illustrator.


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Knife project of overlapping curve does not select all faces
I have a curve that has an Object bevel applied to it. When I knife-project this curve onto a mesh, areas where the curve self-intersects--through overlap, or tight corners--faces do not end up selected in the underlying mesh. (Or, perhaps they are selected and then deselected again.)
Any way to work around this, other than manually selecting the faces after the knife?

Yeah, it's "working" but since you have parts of your cutter mesh overlapping it's gonna have issues selecting everything that you want.

@Jakemoyo If you're confident that there is no workaround (in Blender 4.1), feel free to post that as an answer and I'll accept it.

The closest I've come to making this automated is the following workaround. (I'll not be accepting this answer, as it requires roundtripping the curve through Adobe Illustrator.)

Do not bevel the curve in Blender. Convert the curve to Grease Pencil, and then output that Grease Pencil as SVG.
Open the SVG in Adobe Illustrator, stroke the path at the width you want (which is hard, because now you've switched from world units in Blender to arbitrary point units in Illustrator), and then use Object > Path > Outline Stroke to create a new vector object that has inside and outside curves.

If the exact stroke width is important, the best workaround I've found is to take a close-up screenshot of the curve beveled in Blender to the exact desired width, bring that image into Illustrator, scale it so that its points match the points of the imported path, and then adjust the stroke to match the screenshot.
Optional: if your grease pencil has many points compared to your original curve, you may want to use Object > Path > Simplify... before outlining, to reduce the geometry.

If there are multiple discrete paths that overlap each other, use the Pathfinder palette in Illustrator and use the Unite Shape Mode to remove any overlapping regions.
Save this object as SVG from Illustrator, and import the SVG as Grease Pencil into Blender.

Convert the Grease Pencil into a Bezier or Poly Curve. (Bezier curves have problems with inside/outside fill, but that's not relevant here.) Inside "faces" may not be filled, but that's OK.
Now, you can knife project this new curve with non-overlapping polys and get the desired result!

Per the answer to this question, zoom in/out of the viewport before applying Knife Project to get the desired precision.


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How to replace material on multiple objects?
My task is to import the same car into the scene several times and make them differ in color. But the fact is that a car consists of many parts that are different objects. Some machine parts have several material slots at once.
When I do it manually, I select the part, duplicate the material, change the color in it. Next, I select the next part, change the material to the one just created by duplication. And so on until I sort out all the details of this car.
Is there a way to make it faster? I need to change colors in this way for 20 cars.

Why import the car several times? Why not import only once set up materials, save it,  then modify only the colors that changed?

@DuarteFarrajotaRamos, I meant import not from obj, fbx or other third party formats. I meant append or link. Or, for example, as an asset from the asset browser.

Let's say I imported the model into the scene once. How do I make multiple duplicates of this car but with different colors?


text:
Extruding a circle along a curve resulting in a flat end at one end
So I extruded the circle along the line but every time it ends up with a flat end. The start is fine but I can't get it to stay circular.

maybe make sure that the vertices radius of your curve are at 1, or please share your file

https://drive.google.com/file/d/1pWS2gsO0Dq1NLQh-ysXwmNbRMeBWmUhz/view?usp=sharing

Open your N panel and see the Transform values, your curve is scaled at 0.045 on X, so you need to apply the scale (CtrlA), also once applied, switch to Edit mode, select all the vertices and right click >  Set Curve Radius > 1 and Enter


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dont see material propeties when i have render engine selected to Cycles
Hi everyone I have a question, I just started using blender and I'm watching a video of making a donut to learn the basics, on the video they recommend changing the render engine type to cycles and I do that and it makes the 3d donut look better, after changing the engine he goes to material properties and keeps making changes like the color or the roughness, but when I go there I don't get those options the only way for me to change the material properties is to change the render engine back to eevee do any change necessary then switch it back to cycles
The first picture shows the material properties I get for Eevee render engine

The 2nd image is the material properties options that I get when I have the render engine to Cycles

Is this normal or how do I fix this problem I'm having

That is strange - they should be there. I'm guessing you're using 2.91? Are you using an alpha build? It shouldn't matter because I tested on 2.91 alpha and I cannot recreate your problem, but I assume the alpha version is more prone to variable behavior on different systems. Maybe try a different version? (anything 2.83+ is solid)

thanks for the quick reply
I downloaded a older version (2.83) and open the same project and had the same issue.
Since that didn't work I tried something different and  open the last version (2.91), but created a new general project and change the rendering to cycles, then I went to the material properties of the square that shows up when you first create a new project and I did see the options there, so I ended up using the append option to import the objects from the old project to the new one and I was able to see the material properties of those object too

Damn, that was going to be my other suggestion - copy and paste into a new file.  Sometimes (not often) things get either messed up with the file, or the project settings, and getting your scene into a new file helps for some unexplained reason. Anyway, glad you got a working solution.


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SVG Import Scale
I created SVG file by laser slicer addon at 96dpi as default. I then for certain reason, imported back into blender,  the dimensions are not correct. and is always around 6.7% more. By calculation, the importer may have used 90dpi for calculation. Is there any way to correct this scale problem without scale the imported object, or export 2nd time at 90dpi?
This is similar to other import svg problem, but most answers solve by scaling before export.

https://blender.stackexchange.com/questions/44520/why-are-my-svg-imports-so-small

This tells me that blender handles svg without unit as pixel. I also googled SVGUnits, and a page tells me that SVG specification's default is 90dpi. This still does not solve my problem.


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Duplicated vertices created by bmesh.ops.bisect_plane
I want to get a mesh's bisected surface's vertices and edges. I tried to bisect a sphere using bmesh.ops.bisect_plane.
import bpy
from  bpy import context
import bmesh

bpy.ops.mesh.primitive_uv_sphere_add(radius=0.05)
ob = context.object
me = ob.data
bm = bmesh.new()
bm.from_mesh(me)

origin = (0,0,0)
axis = [(1, 0, 0), (0, 1, 0), (0, 0, 1)]
dir = 1

geo = bmesh.ops.bisect_plane(bm, geom = bm.edges[:] + bm.faces[:], dist = 0, plane_co = origin, plane_no = axis[dir], clear_outer = False, clear_inner = False)['geom_cut']
print('geo len:',len(geo))

verts = [v for v in geo if isinstance(v, bmesh.types.BMVert)]
edges = [e for e in geo if isinstance(e, bmesh.types.BMEdge)]

print('newverts len:',len(verts))
print('newedges len:',len(edges))

for v in verts:
    print(v.co[0],',',v.co[1],',',v.co[2])

Everything seems ok. But, when I bisect using XZ or YZ plane, the number of vertices and edges created are different. Besides, there are many very close vertices created. For example,
-3.91155481338501e-08 , 0.0 , -0.04999999701976776
-5.314408468848342e-08 , 0.0 , 0.04999999701976776
-2.421438694000244e-08 , 0.0 , -0.04999999701976776
-3.757856248398639e-08 , 0.0 , 0.04999999701976776
-1.6298145055770874e-08 , 0.0 , -0.04999999701976776
-2.71779967420116e-08 , 0.0 , 0.04999999701976776
-1.0710209608078003e-08 , 0.0 , -0.04999999701976776
-1.9217743840727053e-08 , 0.0 , 0.04999999701976776
-6.51925802230835e-09 , 0.0 , -0.05000000074505806
-1.2469362431488662e-08 , 0.0 , 0.04999999701976776
-3.14321368932724e-09 , 0.0 , -0.05000000074505806

After removed all these "duplicated" vertices, the number of vertices created is then same when bisecting on both planes.
Is there anything wrong in the code? Or is this normal?

The issue occurs at the "north and south pole" vertices. where, for default sphere each have 32 linked edges.   Added to this the default sphere already has edges exactly where you are bisecting (for each axis)  Would say what you are seeing is "normal" and within the precision of blender, and as noted can be cleared by removing doubles.   For a UV sphere could instead choose edges where both verts are x~=0 for ZY plane, etc.

Thanks for let me know. This happens on Ico Sphere too.

NP. Would make for an interesting routine to instead select all verts lying on cut plane pick one and walk edges until get back to it.   Which may require cutting across a face if two verts selected without an edge between them akin to this  etc. However prob much easier to bisect and remove doubles.


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Using python to scale/resize a selected groups of faces with individual origin
question based on this topic Using python and bmesh to scale/resize a face in place where each face was scaled separately.
So actually the question in the title. I'm newbie to python. I tried to find connected faces based on the same vertex indexes, then calculate the average mean of the vertices positions included this faces(like a origin point).
But it works only for single group faces, how to make it for multiple group faces?

import bpy
import bmesh
import numpy as np
from mathutils import Vector as vec

#EDIT mode#
me = bpy.context.edit_object.data
bm = bmesh.from_edit_mesh(me)
scale_factor = 0.5

seleted_vert_group = []
verts_co_x = []
verts_co_y = []
verts_co_z = []

#checking for matches
for face1 in bm.select_history:
    passwither = 0 #pass double matched face
    for face2 in bm.select_history:
        if face1 == face2:
            continue
        for vert1 in face1.verts:
            for vert2 in face2.verts:
                if passwither == 1:
                    continue
                if vert1.index == vert2.index:
                    passwither = 1
                    print(f'face index: {face1.index}')
                    for vert in face1.verts:
                        seleted_vert_group.append(vert)
                        verts_co_x.append(vert.co.x)
                        verts_co_y.append(vert.co.y)
                        verts_co_z.append(vert.co.z)

co_x = np.sum(verts_co_x)/len(verts_co_x)
co_y = np.sum(verts_co_y)/len(verts_co_y)
co_z = np.sum(verts_co_z)/len(verts_co_z)
origin_point = vec((co_x,co_y,co_z))

for vert in set(seleted_vert_group):
    vert.co = origin_point + scale_factor * (vert.co - origin_point)

bmesh.update_edit_mesh(me)

Find connected islands

Tag all selected faces as false
Pop one selected face tag as true
Yield recursively to find all selected and connected faces (an island)
Scale the verts of the island based on average vert loc. (Could use face centers instead)
Remove the island from selected set

See image on how this may not work as expected for faces touching at vertex corners.
import bpy
import bmesh
from mathutils import Vector, Matrix

#EDIT mode#
me = bpy.context.edit_object.data
bm = bmesh.from_edit_mesh(me)
scale_factor = 0.5

faces = set(f for f in bm.faces if f.select)

def walk_island(face):
    face.tag = True
    yield face
    faces = [f for e in face.edges for f in e.link_faces if not f.tag and f.select]
    for f in faces:
        yield from walk_island(f)

def scale(island):
    verts = set(v for f in island for v in f.verts)
    bmesh.ops.scale(
        bm,
        verts=list(verts),
        vec=(scale_factor,) * 3,
        space=Matrix.Translation(
            sum((-v.co for v in verts), Vector()) / len(verts)
            ))

for f in faces:
    f.tag = False

while faces:
    f = faces.pop()
    island = set(walk_island(f))
    scale(island)
    faces -= island

bmesh.update_edit_mesh(me)

Hi you should move back them into first position.
I answered based on this question

import bpy
import bmesh

context = bpy.context

ob = context.edit_object
me = ob.data
bm = bmesh.from_edit_mesh(me)
scale_factor = 0.5

for face in bm.select_history:
        center = face.calc_center_median()
        for v in face.verts:
            v.co = center + scale_factor * (v.co - center)

bmesh.update_edit_mesh(me)

The problem this method is that the connected edges will have a double scale


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Need to change pivot points during animation
First of all sorry for my english.
I create an animation of duplicating triangles that are ultimately to create a shape. Triangles are created by rotating around a vertex or edge. The problem arises when the first group of triangles appears (dark gray in the picture) and I would like the shape to grow. To achieve this, it is necessary to change the pivot point.
How can this be done?

If what you want to do is a series of rotations for your triangle, what you could do is use Child Of constraints with some empties:

Create an empty at the first pivot point of the triangle, give your triangle a Child Of constraint with the empty as Target, press the Set Inverse button, keyframe the empty:

Rotate the empty, keyframe the rotation, put the 3D cursor on the second pivot point, create an empty, give your triangle a second Child Of constraint with this second empty as Target and Set Inverse, keyframe this empty:

Rotate this second empty, keyframe.


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Black background on Alpha

Do you guys know how I can render it in alpha?
I checked the transparent check box under the Film.
But it still renders with a black background. I'm rendering it in Eevee btw. Thanks!

The problem here is Lens Distortion Filter you added in the Compositor. Because these distortions are calculated on color values (especially dispersion), the transparent area is taken as RGB 0/0/0 i.e. black.
To get back the transparency, you could plug the Alpha output of the Render Layers node into the Alpha input of the Composite and Viewer nodes.
Of course in this case, all distortion / dispersion that extends the alpha of the original image will not be visible because it becomes transparent.
You could take the original Alpha and mix in a copy of the Lens Distortion node before plugging it into the Composite/Viewer alpha, this helps but dispersion doesn't look the same as on black background.
See the attached image for comparison:

If you use the original alpha, the silhouette of the cube isn't distorted, the dispersion is almost invisible except for some skewed looking edges.
The alpha with dispersion takes the distortion/dispersion into account and makes the distorted part going from opaque to transparent according to its brightness.
This is how the dispersion normally looks on a black background and how it's calculated on a transparent background.
If you take the result from 2. and alpha over it on a black background it comes close to the real dispersion of number 3. However, it's not as colorful because of the transparency.
Here comes the problem: since real dispersion is splitting up the colors into spectral colors, on a white background it looks quite multicolored.
But if you just take the dispersion from the transparent image and alpha it over a white background, the multicolor is gone since the dispersion only worked on the blue of the cube and not the background.

how do I fix it??

To answer that I need to know what you actually wanted to achieve with the Ellipse Mask.  In many cases the background is transparent to put one layer above another layer, so that the underlying layer can be seen in the transparent area of the upper layer. For this you would take an Alpha Over node. But for that you wouldn't need an Ellipse Mask - so what was it supposed to do?

By the way, the Denoise Node you've put in there is for raytracing renderers, so it's not really helping when rendering in Eevee.

I'm sorry, I was wrong. I'll edit my answer.

Hope my answer is better now.


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broken script to bake keyframes from driver controlled shape keys
I found a script on the web that is supposed to set key frames for driver driven shape keys. however its giving me an error. I need this so i can remove the drivers for the render farm I use wont allow scripts. Here is the script.
Import bpy

context = bpy.context
scene = context.scene
object = context.object

frame = scene.frame_start

while frame <= scene.frame_end:
scene.frame_set(frame)
for fcurve in object.data.shape_keys.animation_data.drivers.valu es():
object.data.shape_keys.keyframe_insert(fcurve.data _path)
frame = frame + 1

The error I get when ran is below

What was this workaround you found?

Just some syntactic errors (missing indents, etc.). Should work like this:
import bpy

context = bpy.context
scene = context.scene
object = context.object

frame = scene.frame_start

while frame <= scene.frame_end:
    scene.frame_set(frame)
    for fcurve in object.data.shape_keys.animation_data.drivers.values():
        object.data.shape_keys.keyframe_insert(fcurve.data_path)
    frame = frame + 1

# You also need to remove the drivers for the keyframes to take effect:

drivers = object.data.shape_keys.animation_data.drivers
drivers_to_remove = list()
for fcurve in object.data.shape_keys.animation_data.drivers.values():
    data_path = fcurve.data_path
    sk_name = data_path.split('key_blocks["')[1].rsplit('"].value')[0]
    drivers_to_remove.append(fcurve)

for driver in drivers_to_remove:
    print(f'removing driver {driver}')
    drivers.remove(driver)

This worked perfectly, however I now need to use this script to set key frames for shape keys on all frames of this animation. Do i just remove" _data. driver.drivers.values" from line 11?

Tried altering the script to get it to set keyframes for the shapekeys for all frames but the result did not get me what i wanted. here is what i tried. 'code' import bpy
context = bpy.context
scene = context.scene
object = context.object
frame = scene.frame_start
while frame <= scene.frame_end:
scene.frame_set(frame)
object.data.shape_keys.keyframe_insert
frame = frame + 1

Sorry, but can you please specify your problem? The script sets all keyframes for the current object for all applied drivers, between the scene's start frame and its endframe. So it works for all frames. Or do you want it to make it for all objects?

All is well, figured a work around. You have been awesome. Thanks my man.

You also need to remove drivers for the keyframes to take effect - https://pastebin.com/EvQ05uYX


text:
How do I get a driver variable to taper down to 0 once the variable is doubled?
I have a driver that is expressed as "var if var<=0.26666 else needsomethinghere". when var reaches 0.26666 in the local space x axis, I would like for else to taper my variable down to 0 once my object reaches .57 on the x axis. If i need to add another variable im fine with it. Just want my object to follow until .26666 and then .26667 all the way up to .57 brings my object back to 0.0 on the xaxis. currently ive placed 0 for else, which jumps it down to 0.0 past .26666. changing i the direction of my driver in the negative x past .26666 is the desired result.

This question may be a duplicate of this other question.

In order to get the value moving back down towards zero once the bound has been reached you simply need to specify an expression that gives the desired result. The key is to think about the boundary cases - in this case, what happens at 0.26666
So, up to 0.26666 you want the output to be var
Above 0.26666 you want it to move back towards 0 - so you need to subtract var ie, -var, BUT, at 0.26666 you want it to equal 0.26666... ie, you want it to be (0.26666*2) - var
This would result in the expression var if var < 0.26666 else 0.53332 - var.
You can actually link multiple of these conditionals together so you may want it to stay at zero once it reaches zero. ie,

below 0.26666 : var

0.26666 -> 0.53332 : 0.53332 - var

over 0.53332 : 0

This could be produced with :
var if var < 0.26666 else 0.53332 - var if var < 0.53332 else 0

Nest the ternary expressions
The needsomethingelsehere bit is
 a * (a - x) / (b - a) + a if x <= b else 0

which is the linear equation created from two points  (a, a) and (b, 0)  up to b else 0.
equivalently, could use
 max(0, a + a * (a - x) / (b - a))

which will set to zero for any x > b , if b > a > 0
Edit just noticed that you stipulated doubled, which would be a matter of substituting 2 * a for b in equation above, which will reduce it down to.
max(0, 2 * a - x)

Test run in python console for var in one tenth increments from 0 to 1. a, b = 0.2666, 0.57
>>> for i in range(10):
...     x = i / 10
...     print("%3.1f" % x, x if x < 0.2666 else max(0, 0.2666 + 0.2666 * (0.2666 - x) / (0.57 - 0.2666)))
...
0.0 0.0
0.1 0.1
0.2 0.2
0.3 0.237251153592617
0.4 0.1493803559657218
0.5 0.0615095583388266
0.6 0
0.7 0
0.8 0
0.9 0

Suggest using a custom property on some object for a and b and using as vars in driver expressions, makes it easier to change the ranges down the line.


text:
Dos window opens along with Blender application. Is it safe?
I have recently installed blender. Whenever I try to open the blender, a DOS window opens. It closes when I close the blender application. Is it safe?

That is the console window, it is normal and expected

Yes, it is safe. It appears to everybody that uses Blender.

it can be useful to see some system messages, you can use the menu "Toggle Window Fullscreen (Alt-F11)" to hide it . Except on linux, where this is not available (to see those messages you have to start blender from a terminal).

The console window is the main part of Blender. If you are lucky, try closing the dos window before it loads the Blender UI, you will see that Blender automatically closes.