Fast PBR Particles is a cinematic physically based particle system that is very cheap on CPU and can run even on old Graphics API.Fast PBR Particles is a mesh-based particle system that generates its geometry once and then evaluates all particle behaviour entirely in the shader, enabling cinematic effects with minimal CPU cost and excellent platform coverage.Core principlesMinimal CPU workload: particle meshes are built once; there is no per-frame CPU simulation, all temporal evolution is evaluated on the GPU with single-draw-call rendering.Broad graphics API support: despite the simulation happening on GPU, it doesn’t require any advanced features targeting nearly all mainstream graphics APIs including OpenGL(ES) 2.0, DirectX 9.0, and all modern API. while preserving the same feature set.Physically based imaging: motion blur, depth of field, inter-frame temporal control, and exposure are derived from physical optical phenomenons with strict energy conservation.FeaturesPhysically based motion blur from shutter interval by stretching the particle footprint (no post-process required).Physically based depth of field: bokeh radius derived from physical camera paremeters or volumes.Energy conservation: fixed per-particle energy over the shutter interval.Temporal controls: between frames blending, closed shutter interval, turbulence.Lit and emissive particle shaders.Deterministic playback and time reversal.Acurate trajectory integrals accout for gravity, drag and wind.Static lights mode: bokeh + camera motion blur for non-moving light points.Made to be extended. Using Unity Burst, Jobs, Unity.Mathematics. Contains 8 test covered unsafe functions. 3 uber shaders are configured with shader_feature, so only the variants that are used are compiled.
