Most renderers carry RGB values through a path. HdRestir instead samples light at four wavelengths, preserves those samples through transport, and converts the resulting spectrum to display color only when the path reaches the image.

This opening chapter builds that representation from the ground up: wavelength packets, CIE color matching, XYZ integration, RGB reconstruction, and the practical decisions needed to keep the CPU and GPU implementations consistent.

A spectrally rendered material sweep showing colored reflections and illumination

Read the full spectral rendering article →