1 files changed, 73 insertions, 0 deletions
diff --git a/extern/mantaflow/preprocessed/fileio/iogrids.cpp b/extern/mantaflow/preprocessed/fileio/iogrids.cpp
index 2f6cdaa6209..2b8ee905f99 100644
--- a/extern/mantaflow/preprocessed/fileio/iogrids.cpp
+++ b/extern/mantaflow/preprocessed/fileio/iogrids.cpp
@@ -954,6 +954,79 @@ template<class T> void readGridVDB(const string &name, Grid<T> *grid)
          1);
 }
 
+template<> void writeGridVDB(const string &name, Grid<int> *grid)
+{
+  debMsg("Writing int grid " << grid->getName() << " to vdb file " << name, 1);
+
+  // Create an empty int32-point grid with background value 0.
+  openvdb::initialize();
+  openvdb::Int32Grid::Ptr gridVDB = openvdb::Int32Grid::create();
+  gridVDB->setTransform(
+      openvdb::math::Transform::createLinearTransform(1. / grid->getSizeX()));  // voxel size
+
+  // Get an accessor for coordinate-based access to voxels.
+  openvdb::Int32Grid::Accessor accessor = gridVDB->getAccessor();
+
+  gridVDB->setGridClass(openvdb::GRID_UNKNOWN);
+
+  // Name the grid "density".
+  gridVDB->setName(grid->getName());
+
+  openvdb::io::File file(name);
+
+  FOR_IJK(*grid)
+  {
+    openvdb::Coord xyz(i, j, k);
+    accessor.setValue(xyz, (*grid)(i, j, k));
+  }
+
+  // Add the grid pointer to a container.
+  openvdb::GridPtrVec gridsVDB;
+  gridsVDB.push_back(gridVDB);
+
+  // Write out the contents of the container.
+  file.write(gridsVDB);
+  file.close();
+}
+
+template<> void readGridVDB(const string &name, Grid<int> *grid)
+{
+  debMsg("Reading int grid " << grid->getName() << " from vdb file " << name, 1);
+
+  openvdb::initialize();
+  openvdb::io::File file(name);
+  file.open();
+
+  openvdb::GridBase::Ptr baseGrid;
+  for (openvdb::io::File::NameIterator nameIter = file.beginName(); nameIter != file.endName();
+       ++nameIter) {
+#  ifndef BLENDER
+    // Read in only the grid we are interested in.
+    if (nameIter.gridName() == grid->getName()) {
+      baseGrid = file.readGrid(nameIter.gridName());
+    }
+    else {
+      debMsg("skipping grid " << nameIter.gridName(), 1);
+    }
+#  else
+    // For Blender, skip name check and pick first grid from loop
+    baseGrid = file.readGrid(nameIter.gridName());
+    break;
+#  endif
+  }
+  file.close();
+  openvdb::Int32Grid::Ptr gridVDB = openvdb::gridPtrCast<openvdb::Int32Grid>(baseGrid);
+
+  openvdb::Int32Grid::Accessor accessor = gridVDB->getAccessor();
+
+  FOR_IJK(*grid)
+  {
+    openvdb::Coord xyz(i, j, k);
+    int v = accessor.getValue(xyz);
+    (*grid)(i, j, k) = v;
+  }
+}
+
 template<> void writeGridVDB(const string &name, Grid<Real> *grid)
 {
   debMsg("Writing real grid " << grid->getName() << " to vdb file " << name, 1);