B1sounours / UnityVoxelMeshGPU

GPU voxel mesh generation and drawing in Unity HDRP

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GPU voxel mesh generation and drawing in Unity HDRP

This is an experiment to generate a cubic voxel chunk mesh as efficiently as possible. This is insanely fast, meshing and drawing at around 650 FPS on my RTX 4090. The mesh generation itself is much faster than that, running at more than 1000 FPS with camera disabled. I did not measure it exactly by doing a build, but it's pretty quick.

This example uses a 3D noise library to generate voxel data. You can control frequency, amplitude and speed of the noise via inspector in Unity. This is also an example on how to use shader graph in conjunction with Graphics.DrawProceduralIndirect. This was made possible when Unity added VertexId node to shader graph.

movie_015.mp4

How it works

  • generate voxels compute -> voxel data (0/1) is generated using 3d noise
  • feedback compute -> iterates all voxels and calculates the count of vertices and indices which will be required for the mesh
  • voxelizer compute -> iterates all voxels and writes vertex and index data into the buffers
  • the mesh is drawn with Graphics.DrawProceduralIndirect using data from index and vertex buffers

The mesh is generated on the GPU and is never read back to the CPU to create a Mesh object, that would be very slow by comparison (5 FPS).

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GPU voxel mesh generation and drawing in Unity HDRP

License:Apache License 2.0


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