Rendering Compute shader generated mesh.

Hello.

To give some background, I am creating my own volumetric terrain engine, and working on adding grass and other plants. I am using a compute shader to generate the large grass patches based on the generated height map. I am aware I can extract this with getData() on the compute buffer in C# and set to the MeshFilter.mesh, however as extracting from GPU memory to CPU memory is slow, I am wonder if there is a way to render the mesh directly via the Compute Buffers native pointer (GetNativeBufferPtr()).

EDIT: I have found that there is a function GetNativeVertexBufferPtr() (as well as an index one) in the Mesh class. Unfortunately, there does not seem to be a way to set it from the Mesh class. From what I know of low level graphics APIs, these should be compatible as long as the compute buffer has the same stride. From what I can tell there is no technical reason Unity cannot do this. It's a manner of having the correct API for it exposed.

 

So yes & no. You can't use the data generated from a compute shader in a mesh filter, or with a

DrawMesh

call. Instead you'd want to use

DrawProcedural

or

DrawProceduralIndirect

and use a custom shader that uses

SV_VertexID

to index from buffer directly.