Cycles: Tweak to leaf creation criteria in all BVH types

Since leaf node gets split further into per-primitive type leaves old check
for number of curves became a bit ridiculous -- it might lead to two leaf nodes
each of which would contain only one curve primitive (one motion curve and one
regular curve).

This lead to quite dramatic slowdown for Victor model -- around 40%, which is
totally unacceptable.

This commit is aimed to prevent such situation and from quick render test it
seems victor is now back to normal render time. Further testing is needed tho.

There are also other ideas about splitting the node, will need to look into
them next.

1 files changed, 7 insertions, 2 deletions

diff --git a/intern/cycles/bvh/bvh_build.cpp b/intern/cycles/bvh/bvh_build.cpp
index da263c4945e..3f56be0c538 100644
--- a/intern/cycles/bvh/bvh_build.cpp
+++ b/intern/cycles/bvh/bvh_build.cpp
@@ -329,17 +329,22 @@ bool BVHBuild::range_within_max_leaf_size(const BVHRange& range)
 	
 	size_t num_triangles = 0;
 	size_t num_curves = 0;
+	size_t num_motion_curves = 0;
 
 	for(int i = 0; i < size; i++) {
 		BVHReference& ref = references[range.start() + i];
 
-		if(ref.prim_type() & PRIMITIVE_ALL_CURVE)
+		if(ref.prim_type() & PRIMITIVE_CURVE)
 			num_curves++;
+		if(ref.prim_type() & PRIMITIVE_MOTION_CURVE)
+			num_motion_curves++;
 		else if(ref.prim_type() & PRIMITIVE_ALL_TRIANGLE)
 			num_triangles++;
 	}
 
-	return (num_triangles < params.max_triangle_leaf_size) && (num_curves < params.max_curve_leaf_size);
+	return (num_triangles < params.max_triangle_leaf_size) &&
+	       (num_curves < params.max_curve_leaf_size);
+	       (num_motion_curves < params.max_curve_leaf_size);
 }
 
 /* multithreaded binning builder */