Various implementations of Jos Stam fluid sim paper, with performance comparison.
Based on Jos Stam papaer "Real-Time Fluid Dynamics for Games" https://pdfs.semanticscholar.org/847f/819a4ea14bd789aca8bc88e85e906cfc657c.pdf This is close to original implementation, with only changes to boundaries calculations
Use Unity Vector3 struct. Added support of colored dye. Suffers from weak performance due to many Vector3.ctor() calls during maths operations.
Has better performance than previous one, but still worse than Stam's original code
Due to implementation specifics the visual result is slightly different from Original Stam. It happens because deltaTime is significantly lower.
There is a chance of even more increase of performance by using Unity.Mathematics float3 struct (could be tested down the line)
There is noticable artifacts when deltaTime gets lower 10ms. Probably can be solved by algorithms parameters tweaking, but for the purpose of this comparison it's not important.
Note: Tested on IL2CPP standalone build, x86_64, i7-8750H, GTX1050 MaxQ
| Implementation | frame time (ms) |
|---|---|
| Original | 15ms |
| Struct | 34ms |
| Struct Optimized | 26ms |
| DOTS | 7.2ms |
| DOTS + Burst | 5.8ms |
| Compute Shaders | ~3ms |