Add check in EWA filtering case for zero-length minor ellipse axis: avoid NaNs in that case.
Add check in EWA filtering case for zero-length minor ellipse axis: avoid NaNs in that case.
patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin,patwonder/pbrt-v2-skin