Sergey Sharybin
03013c2317
Previously, hair strands of zero length of too few control points would have been ignored. This is fine for a render without motion blur. But once motion blur is enabled it is becoming more tricky to match topology. Even more, it was causing access (and possibly writes) past the array boundaries in case when time step 0 ignored some strands and steps around it did not. If this is becoming problematic for BVH to do reliable intersections this is to be solved on the BVH builder side. The export from Blender to Cycles shouldn't really make decisions there.