DisneyLayeredBRDF work.
Merge branch 'master' into est_disney_material
more work.
Fixed conflicts with master.
Working, but there's a HUGE threading bug.
More work
Working single threaded + bug fixes & small improvements.
Fixed error in last commit.
Merge branch 'master' into est_disney_material
Small fixes.
More work
Merge branch 'master' into est_disney_material
Improved error reporting.
Refactored error reporting.
Removed unused include
Merge branch 'master' into est_disney_material
added variants of Matrix::rotation_x/y/z() taking cosine and sine of rotation angle instead of angle.
reimplemented BezierCurveIntersector::make_projection_transform().
small optimizations.
code simplification and optimization.