Fluid: Updated Mantaflow source files

This update introduces two improvements from the Mantaflow repository:

(1) Improved particle sampling:
- Liquid and secondary particles are sampled more predictably. With all parameters being equal, baked particles will be computed at the exact same position during every bake.
- Before, this was not guaranteed.

(2) Sparse grid caching:
- While saving grid data to disk, grids will from now on be saved in a sparse structure whenever possible (e.g. density, flame but not levelsets).
- With the sparse optimization grid cells with a value under the 'Empty Space' value (already present in domain settings) will not be cached.
- The main benefits of this optimization are: Smaller cache sizes and faster playback of simulation data in the viewport.
- This optimization works 'out-of-the-box'. There is no option in the UI to enable it.
- For now, only smoke simulation grids will take advantage of this optimization.

1 files changed, 16 insertions, 4 deletions

diff --git a/extern/mantaflow/preprocessed/fileio/mantaio.cpp b/extern/mantaflow/preprocessed/fileio/mantaio.cpp
index 3048572261a..fe29890ec11 100644
--- a/extern/mantaflow/preprocessed/fileio/mantaio.cpp
+++ b/extern/mantaflow/preprocessed/fileio/mantaio.cpp
@@ -83,7 +83,9 @@ int save(const string &name,
          bool skipDeletedParts = false,
          int compression = COMPRESSION_ZIP,
          bool precisionHalf = true,
-         int precision = PRECISION_HALF)
+         int precision = PRECISION_HALF,
+         float clip = 1e-4,
+         const Grid<Real> *clipGrid = nullptr)
 {
 
   if (!precisionHalf) {
@@ -102,7 +104,8 @@ int save(const string &name,
   else if (ext == ".vol")
     return writeGridsVol(name, &objects);
   if (ext == ".vdb")
-    return writeObjectsVDB(name, &objects, worldSize, skipDeletedParts, compression, precision);
+    return writeObjectsVDB(
+        name, &objects, worldSize, skipDeletedParts, compression, precision, clip, clipGrid);
   else if (ext == ".npz")
     return writeGridsNumpy(name, &objects);
   else if (ext == ".txt")
@@ -129,8 +132,17 @@ static PyObject *_W_1(PyObject *_self, PyObject *_linargs, PyObject *_kwds)
       int compression = _args.getOpt<int>("compression", 4, COMPRESSION_ZIP, &_lock);
       bool precisionHalf = _args.getOpt<bool>("precisionHalf", 5, true, &_lock);
       int precision = _args.getOpt<int>("precision", 6, PRECISION_HALF, &_lock);
-      _retval = toPy(
-          save(name, objects, worldSize, skipDeletedParts, compression, precisionHalf, precision));
+      float clip = _args.getOpt<float>("clip", 7, 1e-4, &_lock);
+      const Grid<Real> *clipGrid = _args.getPtrOpt<Grid<Real>>("clipGrid", 8, nullptr, &_lock);
+      _retval = toPy(save(name,
+                          objects,
+                          worldSize,
+                          skipDeletedParts,
+                          compression,
+                          precisionHalf,
+                          precision,
+                          clip,
+                          clipGrid));
       _args.check();
     }
     pbFinalizePlugin(parent, "save", !noTiming);