How to make particle effects in PolySpatial?

So I’m trying to create some missiles with a smoke trail and a “launch flame”.

Both particle systems and additive shaders are not working properly.
So what could be a good approach here? Any tips on shaders & particles?

For the PolySpatial Particle System Mode setting, are you using Replicate Properties or Bake to Mesh? Only the latter supports custom (shader graph) shaders; the former maps to RealityKit’s ParticleEmitterComponent. However, additive blending should be possible in either mode. In Bake to Mesh, you should be able to use a shader graph with Surface Type: Transparent and Blending Mode: Additive. With Replicate Properties, you should be able to use a Material with shader “Universal Render Pipeline/Particles/Unlit” and, again, Surface Type: Transparent and Blending Mode: Additive.

If you’re still unable to get additive blending to work, feel free to submit a bug report with a repro case and let us know the incident number (IN-#####). That will help us debug.

Thanks, will look further into that.
I did notice that VisionOS reads Texture sheet animations (in grid mode) different.
My test texture was a 6x6 atlas.
Compared to Unity, the texture has to be flipped vertically to play in the right order (which means it will break in Unity).

Ah, that’s interesting. @connorbell-u might have some more insight, but we do flip texture coordinates when we transfer meshes to RealityKit, so I suspect we’re missing a conversion somewhere. I can look into it.

2022.3.20f1, PolySpatial 1.1.6, URP using the "Universal Render Pipeline/Particles/Unlit” Surface Type: Transparent and Blending Mode: Additive I am seeing pink materials in my compiled builds.

I’m surprised that they’re pink, but we do have an issue where Additive/Premultiply blending wasn’t supported with URP/Particles/Unlit in bake-to-mesh particle mode. That will be fixed in the next release. You might be able to get around it by using a custom shader graph material.

When materials are solid pink, though, it can be an indication that something went wrong with the shader graph asset import. You can try reimporting the shader graph to fix this.

Thank you for the help. Creating a custom shadergraph did the trick and now my transparent/additive shader is rendering just fine.

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