1 files changed, 114 insertions, 0 deletions
diff --git a/source/blender/io/usd/intern/usd_reader_volume.cc b/source/blender/io/usd/intern/usd_reader_volume.cc
new file mode 100644
index 00000000000..871f791c1dd
--- /dev/null
+++ b/source/blender/io/usd/intern/usd_reader_volume.cc
@@ -0,0 +1,114 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2021 Tangent Animation.
+ * All rights reserved.
+ */
+
+#include "usd_reader_volume.h"
+
+#include "BKE_object.h"
+#include "BKE_volume.h"
+
+#include "DNA_object_types.h"
+#include "DNA_volume_types.h"
+
+#include <pxr/usd/usdVol/openVDBAsset.h>
+#include <pxr/usd/usdVol/volume.h>
+
+#include <iostream>
+
+namespace usdtokens {
+
+static const pxr::TfToken density("density", pxr::TfToken::Immortal);
+
+}
+
+namespace blender::io::usd {
+
+void USDVolumeReader::create_object(Main *bmain, const double /* motionSampleTime */)
+{
+  Volume *volume = (Volume *)BKE_volume_add(bmain, name_.c_str());
+
+  object_ = BKE_object_add_only_object(bmain, OB_VOLUME, name_.c_str());
+  object_->data = volume;
+}
+
+void USDVolumeReader::read_object_data(Main *bmain, const double motionSampleTime)
+{
+  if (!volume_) {
+    return;
+  }
+
+  Volume *volume = static_cast<Volume *>(object_->data);
+
+  if (!volume) {
+    return;
+  }
+
+  pxr::UsdVolVolume::FieldMap fields = volume_.GetFieldPaths();
+
+  for (pxr::UsdVolVolume::FieldMap::const_iterator it = fields.begin(); it != fields.end(); ++it) {
+
+    pxr::UsdPrim fieldPrim = prim_.GetStage()->GetPrimAtPath(it->second);
+
+    if (!fieldPrim.IsA<pxr::UsdVolOpenVDBAsset>()) {
+      continue;
+    }
+
+    pxr::UsdVolOpenVDBAsset fieldBase(fieldPrim);
+
+    pxr::UsdAttribute fieldNameAttr = fieldBase.GetFieldNameAttr();
+
+    if (fieldNameAttr.IsAuthored()) {
+      pxr::TfToken fieldName;
+      fieldNameAttr.Get(&fieldName, motionSampleTime);
+
+      /* A Blender volume creates density by default. */
+      if (fieldName != usdtokens::density) {
+        BKE_volume_grid_add(volume, fieldName.GetString().c_str(), VOLUME_GRID_FLOAT);
+      }
+    }
+
+    pxr::UsdAttribute filepathAttr = fieldBase.GetFilePathAttr();
+
+    if (filepathAttr.IsAuthored()) {
+      pxr::SdfAssetPath fp;
+      filepathAttr.Get(&fp, motionSampleTime);
+
+      if (filepathAttr.ValueMightBeTimeVarying()) {
+        std::vector<double> filePathTimes;
+        filepathAttr.GetTimeSamples(&filePathTimes);
+
+        if (!filePathTimes.empty()) {
+          int start = static_cast<int>(filePathTimes.front());
+          int end = static_cast<int>(filePathTimes.back());
+
+          volume->is_sequence = static_cast<char>(true);
+          volume->frame_start = start;
+          volume->frame_duration = (end - start) + 1;
+        }
+      }
+
+      std::string filepath = fp.GetResolvedPath();
+
+      strcpy(volume->filepath, filepath.c_str());
+    }
+  }
+
+  USDXformReader::read_object_data(bmain, motionSampleTime);
+}
+
+}  // namespace blender::io::usd