1 files changed, 57 insertions, 1 deletions

diff --git a/intern/cycles/render/image_vdb.cpp b/intern/cycles/render/image_vdb.cpp
index 3f7dd45ee88..5d0999d5623 100644
--- a/intern/cycles/render/image_vdb.cpp
+++ b/intern/cycles/render/image_vdb.cpp
@@ -20,6 +20,9 @@
 #  include <openvdb/openvdb.h>
 #  include <openvdb/tools/Dense.h>
 #endif
+#ifdef WITH_NANOVDB
+#  include <nanovdb/util/OpenToNanoVDB.h>
+#endif
 
 CCL_NAMESPACE_BEGIN
 
@@ -53,41 +56,84 @@ bool VDBImageLoader::load_metadata(ImageMetaData &metadata)
   /* Set data type. */
   if (grid->isType<openvdb::FloatGrid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(*openvdb::gridConstPtrCast<openvdb::FloatGrid>(grid));
+#  endif
   }
   else if (grid->isType<openvdb::Vec3fGrid>()) {
     metadata.channels = 3;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(*openvdb::gridConstPtrCast<openvdb::Vec3fGrid>(grid));
+#  endif
   }
   else if (grid->isType<openvdb::BoolGrid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::FloatGrid(*openvdb::gridConstPtrCast<openvdb::BoolGrid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::DoubleGrid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::FloatGrid(*openvdb::gridConstPtrCast<openvdb::DoubleGrid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::Int32Grid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::FloatGrid(*openvdb::gridConstPtrCast<openvdb::Int32Grid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::Int64Grid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::FloatGrid(*openvdb::gridConstPtrCast<openvdb::Int64Grid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::Vec3IGrid>()) {
     metadata.channels = 3;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::Vec3fGrid(*openvdb::gridConstPtrCast<openvdb::Vec3IGrid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::Vec3dGrid>()) {
     metadata.channels = 3;
+#  ifdef WITH_NANOVDB
+    nanogrid = nanovdb::openToNanoVDB(
+        openvdb::Vec3fGrid(*openvdb::gridConstPtrCast<openvdb::Vec3dGrid>(grid)));
+#  endif
   }
   else if (grid->isType<openvdb::MaskGrid>()) {
     metadata.channels = 1;
+#  ifdef WITH_NANOVDB
+    return false;  // Unsupported
+#  endif
   }
   else {
     return false;
   }
 
+#  ifdef WITH_NANOVDB
+  metadata.byte_size = nanogrid.size();
+  if (metadata.channels == 1) {
+    metadata.type = IMAGE_DATA_TYPE_NANOVDB_FLOAT;
+  }
+  else {
+    metadata.type = IMAGE_DATA_TYPE_NANOVDB_FLOAT3;
+  }
+#  else
   if (metadata.channels == 1) {
     metadata.type = IMAGE_DATA_TYPE_FLOAT;
   }
   else {
     metadata.type = IMAGE_DATA_TYPE_FLOAT4;
   }
+#  endif
 
   /* Set transform from object space to voxel index. */
   openvdb::math::Mat4f grid_matrix = grid->transform().baseMap()->getAffineMap()->getMat4();
@@ -98,8 +144,12 @@ bool VDBImageLoader::load_metadata(ImageMetaData &metadata)
     }
   }
 
+#  ifdef WITH_NANOVDB
+  Transform texture_to_index = transform_identity();
+#  else
   Transform texture_to_index = transform_translate(min.x(), min.y(), min.z()) *
                                transform_scale(dim.x(), dim.y(), dim.z());
+#  endif
 
   metadata.transform_3d = transform_inverse(index_to_object * texture_to_index);
   metadata.use_transform_3d = true;
@@ -114,6 +164,9 @@ bool VDBImageLoader::load_metadata(ImageMetaData &metadata)
 bool VDBImageLoader::load_pixels(const ImageMetaData &, void *pixels, const size_t, const bool)
 {
 #ifdef WITH_OPENVDB
+#  ifdef WITH_NANOVDB
+  memcpy(pixels, nanogrid.data(), nanogrid.size());
+#  else
   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);
@@ -153,7 +206,7 @@ bool VDBImageLoader::load_pixels(const ImageMetaData &, void *pixels, const size
     openvdb::tools::Dense<float, openvdb::tools::LayoutXYZ> dense(bbox, (float *)pixels);
     openvdb::tools::copyToDense(*openvdb::gridConstPtrCast<openvdb::MaskGrid>(grid), dense);
   }
-
+#  endif
   return true;
 #else
   (void)pixels;
@@ -183,6 +236,9 @@ void VDBImageLoader::cleanup()
   /* Free OpenVDB grid memory as soon as we can. */
   grid.reset();
 #endif
+#ifdef WITH_NANOVDB
+  nanogrid.reset();
+#endif
 }
 
 bool VDBImageLoader::is_vdb_loader() const