HdRestir 6 — Spectral Path Tracing on the GPU
With the scene resident on the GPU, the spectral path tracer can move from a CPU loop to a persistent compute pipeline. The difficult part is preserving estimator behavior while execution order, random streams, memory lifetime, and debugging tools all change.
This chapter follows the complete GPU path: pass lifetime, frame parameters, dispatch, ray and hit state, spectral transport, accumulation, and the parity tests used to separate expected floating-point differences from real implementation errors.
