Cycles: support rendering new Volume object type

Voxels are loaded directly from the OpenVDB grid. Rendering still only supports
dense grid, so memory usage is not great for sparse volumes, this is to be
addressed in the future.

Ref T73201

1 files changed, 56 insertions, 0 deletions

diff --git a/intern/cycles/render/image_vdb.h b/intern/cycles/render/image_vdb.h
new file mode 100644
index 00000000000..7dec63b11e6
--- /dev/null
+++ b/intern/cycles/render/image_vdb.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2011-2020 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 __IMAGE_VDB__
+#define __IMAGE_VDB__
+
+#ifdef WITH_OPENVDB
+#  include <openvdb/openvdb.h>
+#endif
+
+#include "render/image.h"
+
+CCL_NAMESPACE_BEGIN
+
+class VDBImageLoader : public ImageLoader {
+ public:
+  VDBImageLoader(const string &grid_name);
+  ~VDBImageLoader();
+
+  virtual bool load_metadata(ImageMetaData &metadata) override;
+
+  virtual bool load_pixels(const ImageMetaData &metadata,
+                           void *pixels,
+                           const size_t pixels_size,
+                           const bool associate_alpha) override;
+
+  virtual string name() const override;
+
+  virtual bool equals(const ImageLoader &other) const override;
+
+  virtual void cleanup() override;
+
+ protected:
+  string grid_name;
+#ifdef WITH_OPENVDB
+  openvdb::GridBase::ConstPtr grid;
+  openvdb::CoordBBox bbox;
+#endif
+};
+
+CCL_NAMESPACE_END
+
+#endif /* __IMAGE_VDB__ */