Second-order radiometric ray tracing

This is the authors' abstract. We don't add key points for this paper.

Conventional ray-tracing methods fail for non-Lambertian sources. To address this deficiency, we introduce a radiometric ray-tracing (R2T) method, applicable to quasi-homogeneous sources of arbitrary spatial coherence. Based on Fourier optics, applied to physical radiometry in the radiance transfer function second-order approximation, the R2T method retains the standard ray-tracing codes but modifies them to include phase-space weighting factors attached to conventional geometric rays.