Cycles: add support for BVH refit in OptiX

This avoids recomputing the BVH for geometries that do not have changes in topology but whose vertices are modified (like a simple character animation), and gives up to 40% speedup for BVH building.

This is only available for viewport renders at the moment.

Reviewed By: pmoursnv, brecht

Differential Revision: https://developer.blender.org/D9353

2 files changed, 8 insertions, 2 deletions

diff --git a/intern/cycles/bvh/bvh_optix.cpp b/intern/cycles/bvh/bvh_optix.cpp
index 0527c0eeda8..f2666688123 100644
--- a/intern/cycles/bvh/bvh_optix.cpp
+++ b/intern/cycles/bvh/bvh_optix.cpp
@@ -37,6 +37,9 @@ BVHOptiX::BVHOptiX(const BVHParams &params_,
                    const vector<Object *> &objects_)
     : BVH(params_, geometry_, objects_)
 {
+  optix_handle = 0;
+  optix_data_handle = 0;
+  do_refit = false;
 }
 
 BVHOptiX::~BVHOptiX()
@@ -216,8 +219,7 @@ void BVHOptiX::pack_nodes(const BVHNode *)
 
 void BVHOptiX::refit_nodes()
 {
-  // TODO(pmours): Implement?
-  VLOG(1) << "Refit is not yet implemented for OptiX BVH.";
+  do_refit = true;
 }
 
 BVHNode *BVHOptiX::widen_children_nodes(const BVHNode *)
diff --git a/intern/cycles/bvh/bvh_optix.h b/intern/cycles/bvh/bvh_optix.h
index e4745b093b5..663cba67260 100644
--- a/intern/cycles/bvh/bvh_optix.h
+++ b/intern/cycles/bvh/bvh_optix.h
@@ -33,6 +33,10 @@ class BVHOptiX : public BVH {
   friend class BVH;
 
  public:
+  uint64_t optix_handle;
+  uint64_t optix_data_handle;
+  bool do_refit;
+
   BVHOptiX(const BVHParams &params,
            const vector<Geometry *> &geometry,
            const vector<Object *> &objects);