exposed more sppm photon tracing parameters in appleseed.studio.
fixed incorrect BSDF evaluation in SPPM lighting engine.
updated sppm test scenes.
added the USE_EXTERNAL_ZLIB build option.
decreased the step size of SPPM's Initial Radius spin box from 1.0 to 0.1.
removed todo note, added reference.
added assertions.
added assertion in foundation::normalize(foundation::Vector).
the mesh object reader now detects, reports and corrects null normal vectors.
foundation::small_item_reorder() and foundation::large_item_reorder() are now templatized over the index type.
added assertions.
added foundation::safe_normalize(foundation::Vector).
normals passed to foundation::IMeshBuilder::push_vertex_normal() are no longer guaranteed to be unit-length.