When I have a lot of particle systems using meshes, my the rendering of the particles starts flickering in and out (see the video). I’m not sure what’s going wrong or if this is just a limitation of Unity. I’m using Unity’s URP lit particle shader, the default sphere mesh and mostly default particle system settings.
If you want to recreate this problem you can do as follows:
Create a new URP project (Unity 2020.3). Add a new particle system (PS) to the sample scene. Change the PS Render Mode to mesh and set the mesh to the default sphere. Create a new material using the shader: Universal Render Pipeline/ Particles/Lit and set the PS material to this new material (the material will ask you to fix the Custom Vertex Streams by clicking the button). Make a lot of copies of the PS (~20 in my case) and run the scene. The PS rendering starts flickering.
This looks quite similar to an issue I am having. I’m using particle systems with multiple meshes, selected at random per particle. While they’re flickering, it looks as if the meshes of the particles are getting swapped (and maybe their size as well?). The flickering only happens in play mode, and only on some computers. I found that if I disable ‘GPU Instancing’ under the ‘Renderer’ module, the flickering goes away.
We still have a backport in progress for 2022.1 and 2021.3 for another issue that causes this flickering. So I am hopeful that will fix this. The bad news is that the issue i’m talking about isn’t public in our database, so there is no issue tracker link for it. i’ve no idea why that is
It looks like it’s on track for 2021.3.5f1 though, due for release sometime on or after the 22nd June. Sorry for the inconvenience. If it still happens in that version, I’d say we’ll need another bug report, unfortunately.
Any news on this topic? I have the same issue with meshes and billboard. It happens when I’m too close to them.
The particles have a shader with a depth check.
