1 files changed, 91 insertions, 0 deletions
diff --git a/intern/cycles/hydra/volume.cpp b/intern/cycles/hydra/volume.cpp
new file mode 100644
index 00000000000..7b965c613ed
--- /dev/null
+++ b/intern/cycles/hydra/volume.cpp
@@ -0,0 +1,91 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright 2022 NVIDIA Corporation
+ * Copyright 2022 Blender Foundation */
+
+#include "hydra/volume.h"
+#include "hydra/field.h"
+#include "hydra/geometry.inl"
+#include "scene/volume.h"
+
+HDCYCLES_NAMESPACE_OPEN_SCOPE
+
+// clang-format off
+TF_DEFINE_PRIVATE_TOKENS(_tokens,
+   (openvdbAsset)
+);
+// clang-format on
+
+HdCyclesVolume::HdCyclesVolume(const SdfPath &rprimId
+#if PXR_VERSION < 2102
+                               ,
+                               const SdfPath &instancerId
+#endif
+                               )
+    : HdCyclesGeometry(rprimId
+#if PXR_VERSION < 2102
+                       ,
+                       instancerId
+#endif
+      )
+{
+}
+
+HdCyclesVolume::~HdCyclesVolume()
+{
+}
+
+HdDirtyBits HdCyclesVolume::GetInitialDirtyBitsMask() const
+{
+  HdDirtyBits bits = HdCyclesGeometry::GetInitialDirtyBitsMask();
+  bits |= HdChangeTracker::DirtyVolumeField;
+  return bits;
+}
+
+void HdCyclesVolume::Populate(HdSceneDelegate *sceneDelegate, HdDirtyBits dirtyBits, bool &rebuild)
+{
+  Scene *const scene = (Scene *)_geom->get_owner();
+
+  if (dirtyBits & HdChangeTracker::DirtyVolumeField) {
+    for (const HdVolumeFieldDescriptor &field :
+         sceneDelegate->GetVolumeFieldDescriptors(GetId())) {
+      if (const auto openvdbAsset = static_cast<HdCyclesField *>(
+              sceneDelegate->GetRenderIndex().GetBprim(_tokens->openvdbAsset, field.fieldId))) {
+        const ustring name(field.fieldName.GetString());
+
+        AttributeStandard std = ATTR_STD_NONE;
+        if (name == Attribute::standard_name(ATTR_STD_VOLUME_DENSITY)) {
+          std = ATTR_STD_VOLUME_DENSITY;
+        }
+        else if (name == Attribute::standard_name(ATTR_STD_VOLUME_COLOR)) {
+          std = ATTR_STD_VOLUME_COLOR;
+        }
+        else if (name == Attribute::standard_name(ATTR_STD_VOLUME_FLAME)) {
+          std = ATTR_STD_VOLUME_FLAME;
+        }
+        else if (name == Attribute::standard_name(ATTR_STD_VOLUME_HEAT)) {
+          std = ATTR_STD_VOLUME_HEAT;
+        }
+        else if (name == Attribute::standard_name(ATTR_STD_VOLUME_TEMPERATURE)) {
+          std = ATTR_STD_VOLUME_TEMPERATURE;
+        }
+        else if (name == Attribute::standard_name(ATTR_STD_VOLUME_VELOCITY)) {
+          std = ATTR_STD_VOLUME_VELOCITY;
+        }
+
+        // Skip attributes that are not needed
+        if ((std != ATTR_STD_NONE && _geom->need_attribute(scene, std)) ||
+            _geom->need_attribute(scene, name)) {
+          Attribute *const attr = (std != ATTR_STD_NONE) ?
+                                      _geom->attributes.add(std) :
+                                      _geom->attributes.add(
+                                          name, TypeDesc::TypeFloat, ATTR_ELEMENT_VOXEL);
+          attr->data_voxel() = openvdbAsset->GetImageHandle();
+        }
+      }
+    }
+
+    rebuild = true;
+  }
+}
+
+HDCYCLES_NAMESPACE_CLOSE_SCOPE