Cycles: add Optix device backend

This uses hardware-accelerated raytracing on NVIDIA RTX graphics cards.

It is still currently experimental. Most features are supported, but a few
are still missing like baking, branched path tracing and using CPU memory.
https://wiki.blender.org/wiki/Reference/Release_Notes/2.81/Cycles#NVIDIA_RTX

For building with Optix support, the Optix SDK must be installed. See here for
build instructions:
https://wiki.blender.org/wiki/Building_Blender/CUDA

Differential Revision: https://developer.blender.org/D5363

1 files changed, 53 insertions, 0 deletions

diff --git a/intern/cycles/bvh/bvh_optix.h b/intern/cycles/bvh/bvh_optix.h
new file mode 100644
index 00000000000..35033fe635f
--- /dev/null
+++ b/intern/cycles/bvh/bvh_optix.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2019, NVIDIA Corporation.
+ * Copyright 2019, Blender Foundation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef __BVH_OPTIX_H__
+#define __BVH_OPTIX_H__
+
+#ifdef WITH_OPTIX
+
+#  include "bvh/bvh.h"
+#  include "bvh/bvh_params.h"
+#  include "device/device_memory.h"
+
+CCL_NAMESPACE_BEGIN
+
+class BVHOptiX : public BVH {
+  friend class BVH;
+
+ public:
+  BVHOptiX(const BVHParams &params, const vector<Mesh *> &meshes, const vector<Object *> &objects);
+  virtual ~BVHOptiX();
+
+  virtual void build(Progress &progress, Stats *) override;
+  virtual void copy_to_device(Progress &progress, DeviceScene *dscene) override;
+
+ private:
+  void pack_blas();
+  void pack_tlas();
+
+  virtual void pack_nodes(const BVHNode *) override;
+  virtual void refit_nodes() override;
+
+  virtual BVHNode *widen_children_nodes(const BVHNode *) override;
+};
+
+CCL_NAMESPACE_END
+
+#endif /* WITH_OPTIX */
+
+#endif /* __BVH_OPTIX_H__ */