Rendering without a MeshRenderer

[toxic pecan]

I generate a mesh and apply a material to it with a shader written in HLSL.

The only purpose of this mesh is to be rendered. No physics, no scripts.

When generating this mesh, a lot of time is wasted waiting for the data to be sent from the GPU to the CPU, which I know is generally something you want to avoid.

computeShader.SetBuffer(vertexKernelID, "vertexBuffer", vertexBuffer);
computeShader.Dispatch(vertexKernelID, GetThreadGroups(vertexKernelID, vertices.Length), 1, 1);
vertexBuffer.GetData(vertices); <- Here

computeShader.SetBuffer(triangleKernelID, "triangleBuffer", triangleBuffer);
computeShader.Dispatch(triangleKernelID, GetThreadGroups(triangleKernelID, triangles.Length / 6), 1, 1);
triangleBuffer.GetData(triangles); <- And here

Is there a way to just render it without sending anything back to the CPU?

[foggy sparrow]

solution is probably to use a compute shader + DrawProcedural

[whole ermine]

DrawProcedural is a good way, especially if you want to avoid MeshRenderer entirely. You can also continue to use Mesh and MeshRenderer but avoid the readback from GPU, if you write directly into the GPU vertex and index buffers of a given Mesh.

Then the Mesh will be updated on the GPU side, but not on the CPU.
https://docs.unity3d.com/6000.2/Documentation/ScriptReference/Mesh.GetVertexBuffer.html

Writing to the mesh buffers in a compute shader is a little more complicated than writing to StructuredBuffers, but not too bad.

[toxic pecan]

Isn't DrawProcedrual outdated and replaced by Graphics.RenderPrimitives?

Also would keeping the MeshRenderer have an impact on performance?

[whole ermine]

They both do the same thing, RenderPrimitives just has a different API, but yes you should use the new one.