Skip to content
Shows how to support rendering motion vectors within the standard particle system of Unity.
HLSL C# ShaderLab
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.

Files

Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
Assets
ProjectSettings project cleaning up Sep 21, 2017
.gitattributes
.gitignore Initial commit. Nov 11, 2016
.gitmodules Added submodules. Sep 13, 2017
README.md Updated README Sep 21, 2017

README.md

ParticleMotionVector

This is an example that shows how to support rendering motion vectors within the standard particle system of Unity.

Particles/Standard Opaque with Motion Vectors

inspector

This shader only supports rendering mesh particles without transparency. It may not sound very useful for particle effects in a general sense, but actually useful in some specific cases, like when rendering many small moving objects (asteroids, confetti, etc.) by using a particle system.

movec gif

When using this shader, "Simulation Space" in the main module and "Render Alignment" in the renderer module have to be set to "World". This is needed to calculate rotations correctly in the motion vector writer.

inspector

Also the custom vertex streams have to be set up in the following order:

  • UV (TEXCOORD0.xy)
  • Center (TEXCOORD0.zw|x)
  • Velocity (TEXCOORD1.yzw)
  • Rotation3D (TEXCOORD2.xyz)
  • RotationSpeed3D (TEXCOORD2.w|xy)

vertex streams

System requirements

  • Unity 2017.1 or later

Current limitations

In the current implementation, change of the particle size is ignored in the calculation of motion vectors. This may introduce artifacts when animating the particle size with using the "Size over Lifetime" module or the "Size by Speed" module.

How about transparency?

I haven't tried transparency with motion vectors because I think it works only if someone tweaks it very carefully (and I have no time to invest in it). I won't recommend it, but you can try it anyway.

License

Copyright (c) 2017 Unity Technologies

This repository is to be treated as an example content of Unity; you can use the code freely in your projects. Also see the FAQ about example contents.

You can’t perform that action at this time.