Fix IGI bias-compensation computation: was missing a cos theta term at the point the gather rays hit.
Fix IGI bias-compensation computation: was missing a cos theta term at the point the gather rays hit.
patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin