Package: com.unity.demoteam.mesh-to-sdf
A real-time Signed Distance Field generator. Use a Mesh or a dynamically deforming SkinnedMesh as input to generate a 3D SDF texture every frame.
The SDF can be used by the VFX Graph, the Hair system, and other effects relying on SDFs.
The generator is real-time - to achieve better performance, it sacrifices robustness and the ability to handle large meshes. Typical resolutions would be a 5-8k triangle mesh in a 16^3-64^3 voxel volume. If your mesh is much larger or messy (holes, spiky shapes, etc.), it's best to use a cleaner low-res proxy mesh instead. Note that the SDF generator shipping with the VFX Graph has a more robust handling of larger or messy meshes, but it's slower.
The generator works by first splatting distances into voxels in a small area around each triangle, then using either a linear flood or jump flood to fill the rest of the volume.
Performance
Tested with a 32^3 voxel volume, 5k triangle mesh
- jump flood: RTX3090 0.22ms
- linear flood, 8 iterations: RTX3090 0.18ms, RTX2080Super 0.21ms
Requirements
- Unity 2021.2+ (mesh buffer access in compute shaders)
- Compute shaders supported on target platform
Installation
Use Add package from git URL (in the Package Manager):
https://github.com/Unity-Technologies/com.unity.demoteam.mesh-to-sdf.git
or
Declare the package as a git dependency in Packages/manifest.json:
"dependencies": {
"com.unity.demoteam.mesh-to-sdf": "https://github.com/Unity-Technologies/com.unity.demoteam.mesh-to-sdf.git",
...
}
Documentation
Examples
Samples included with the package show basic setup and are described in the doc above.
The mesh-to-sdf examples project is a vfx demo, with the dynamic SDFs driving VFX Graph effects and a raymarching shader:
mesh-to-sdf.mov
Acknowledgements
The core functionality of the generator (initial splatting of distances around mesh faces) uses the implementation from TressFX published by AMD under the MIT license. Thank you!