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, 188 insertions, 0 deletions

diff --git a/intern/cycles/render/image_vdb.cpp b/intern/cycles/render/image_vdb.cpp
new file mode 100644
index 00000000000..500131c2d84
--- /dev/null
+++ b/intern/cycles/render/image_vdb.cpp
@@ -0,0 +1,188 @@
+/*
+ * 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.
+ */
+
+#include "render/image_vdb.h"
+
+#ifdef WITH_OPENVDB
+#  include <openvdb/openvdb.h>
+#  include <openvdb/tools/Dense.h>
+#endif
+
+CCL_NAMESPACE_BEGIN
+
+VDBImageLoader::VDBImageLoader(const string &grid_name) : grid_name(grid_name)
+{
+}
+
+VDBImageLoader::~VDBImageLoader()
+{
+}
+
+bool VDBImageLoader::load_metadata(ImageMetaData &metadata)
+{
+#ifdef WITH_OPENVDB
+  if (!grid) {
+    return false;
+  }
+
+  bbox = grid->evalActiveVoxelBoundingBox();
+  if (bbox.empty()) {
+    return false;
+  }
+
+  /* Set dimensions. */
+  openvdb::Coord dim = bbox.dim();
+  openvdb::Coord min = bbox.min();
+  metadata.width = dim.x();
+  metadata.height = dim.y();
+  metadata.depth = dim.z();
+
+  /* Set data type. */
+  if (grid->isType<openvdb::FloatGrid>()) {
+    metadata.channels = 1;
+  }
+  else if (grid->isType<openvdb::Vec3fGrid>()) {
+    metadata.channels = 3;
+  }
+  else if (grid->isType<openvdb::BoolGrid>()) {
+    metadata.channels = 1;
+  }
+  else if (grid->isType<openvdb::DoubleGrid>()) {
+    metadata.channels = 1;
+  }
+  else if (grid->isType<openvdb::Int32Grid>()) {
+    metadata.channels = 1;
+  }
+  else if (grid->isType<openvdb::Int64Grid>()) {
+    metadata.channels = 1;
+  }
+  else if (grid->isType<openvdb::Vec3IGrid>()) {
+    metadata.channels = 3;
+  }
+  else if (grid->isType<openvdb::Vec3dGrid>()) {
+    metadata.channels = 3;
+  }
+  else if (grid->isType<openvdb::MaskGrid>()) {
+    metadata.channels = 1;
+  }
+  else {
+    return false;
+  }
+
+  if (metadata.channels == 1) {
+    metadata.type = IMAGE_DATA_TYPE_FLOAT;
+  }
+  else {
+    metadata.type = IMAGE_DATA_TYPE_FLOAT4;
+  }
+
+  /* Set transform from object space to voxel index. */
+  openvdb::math::Mat4f grid_matrix = grid->transform().baseMap()->getAffineMap()->getMat4();
+  Transform index_to_object;
+  for (int col = 0; col < 4; col++) {
+    for (int row = 0; row < 3; row++) {
+      index_to_object[row][col] = (float)grid_matrix[col][row];
+    }
+  }
+
+  Transform texture_to_index = transform_translate(min.x(), min.y(), min.z()) *
+                               transform_scale(dim.x(), dim.y(), dim.z());
+
+  metadata.transform_3d = transform_inverse(index_to_object * texture_to_index);
+  metadata.use_transform_3d = true;
+
+  return true;
+#else
+  (void)metadata;
+  return false;
+#endif
+}
+
+bool VDBImageLoader::load_pixels(const ImageMetaData &, void *pixels, const size_t, const bool)
+{
+#ifdef WITH_OPENVDB
+  if (grid->isType<openvdb::FloatGrid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::FloatGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::Vec3fGrid>()) {
+    openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
+        bbox, (openvdb::Vec3f *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3fGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::BoolGrid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::BoolGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::DoubleGrid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::DoubleGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::Int32Grid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Int32Grid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::Int64Grid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Int64Grid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::Vec3IGrid>()) {
+    openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
+        bbox, (openvdb::Vec3f *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3IGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::Vec3dGrid>()) {
+    openvdb::tools::Dense<openvdb::Vec3f, openvdb::tools::LayoutXYZ> dense(
+        bbox, (openvdb::Vec3f *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::Vec3dGrid>(grid), dense);
+  }
+  else if (grid->isType<openvdb::MaskGrid>()) {
+    openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
+    openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::MaskGrid>(grid), dense);
+  }
+
+  return true;
+#else
+  (void)pixels;
+  return false;
+#endif
+}
+
+string VDBImageLoader::name() const
+{
+  return grid_name;
+}
+
+bool VDBImageLoader::equals(const ImageLoader &other) const
+{
+#ifdef WITH_OPENVDB
+  const VDBImageLoader &other_loader = (const VDBImageLoader &)other;
+  return grid == other_loader.grid;
+#else
+  (void)other;
+  return true;
+#endif
+}
+
+void VDBImageLoader::cleanup()
+{
+#ifdef WITH_OPENVDB
+  /* Free OpenVDB grid memory as soon as we can. */
+  grid.reset();
+#endif
+}
+
+CCL_NAMESPACE_END