Fix #147680: Crash when voxel size is too small

These grid creation functions can return a grid without data when
certain parameters are invalid. The "set_output" function of the
geometry node execution parameters asserts that the data is
not null, so I assume this is invalid and causes crashes later on.

Pull Request: https://projects.blender.org/blender/blender/pulls/147741

source/blender/nodes/geometry/nodes/node_geo_mesh_to_density_grid.cc

@@ -50,6 +50,10 @@ static void node_geo_exec(GeoNodeExecParams params)
       params.extract_input<float>("Voxel Size"),
       params.extract_input<float>("Gradient Width"),
       params.extract_input<float>("Density"));
+  if (!grid) {
+    params.set_default_remaining_outputs();
+    return;
+  }
   params.set_output("Density Grid", std::move(grid));
 #else
   node_geo_exec_with_missing_openvdb(params);

source/blender/nodes/geometry/nodes/node_geo_mesh_to_sdf_grid.cc

@@ -45,6 +45,10 @@ static void node_geo_exec(GeoNodeExecParams params)
       mesh->corner_tris(),
       params.extract_input<float>("Voxel Size"),
       std::max(1, params.extract_input<int>("Band Width")));
+  if (!grid) {
+    params.set_default_remaining_outputs();
+    return;
+  }
   params.set_output("SDF Grid", std::move(grid));
 #else
   node_geo_exec_with_missing_openvdb(params);