Large volume components (#6364)

* Large Volume Components

* impl

Author: Grantim

source/MRMesh/MRMeshComponents.cpp

@@ -205,6 +205,29 @@ FaceBitSet getLargeByAreaComponents( const MeshPart& mp, float minArea, const Un
     return getLargeByAreaComponents( mp, unionFind, minArea );
 }
 
+FaceBitSet getLargeByVolumeComponents( const MeshPart& mp, float minVolume )
+{
+    if ( !mp.mesh.topology.isClosed( mp.region ) )
+    {
+        assert( !"getLargeByVolumeComponents: require closed mesh part" );
+        return {};
+    }
+    auto mapAndNum = MeshComponents::getAllComponentsMap( mp );
+    Vector<double, RegionId> volumes( mapAndNum.second, 0.0 );
+    auto region = mp.mesh.topology.getFaceIds( mp.region );
+    for ( auto f : region )
+    {
+        auto fp = mp.mesh.getTriPoints( f );
+        volumes[mapAndNum.first[f]] += mixed( Vector3d( fp[0] ), Vector3d( fp[1] ), Vector3d( fp[2] ) );
+    }
+    BitSetParallelFor( region, [&] ( FaceId f )
+    {
+        if ( std::abs( volumes[mapAndNum.first[f]] ) < minVolume )
+            region.reset( f );
+    } );
+    return region;
+}
+
 Expected<FaceBitSet> expandToComponents( const MeshPart& mp, const FaceBitSet& seeds, const ExpandToComponentsParams& params /*= {} */ )
 {
     if ( params.coverRatio > 1.0f )

source/MRMesh/MRMeshComponents.h

@@ -51,6 +51,10 @@ enum FaceIncidence
 /// returns the union of connected components, each having at least given area
 [[nodiscard]] MRMESH_API FaceBitSet getLargeByAreaComponents( const MeshPart& meshPart, float minArea, const UndirectedEdgeBitSet * isCompBd );
 
+/// returns the union of connected components, each having at least given volume
+/// note that function require closed mesh part
+[[nodiscard]] MRMESH_API FaceBitSet getLargeByVolumeComponents( const MeshPart& meshPart, float minVolume );
+
 /// given prepared union-find structure returns the union of connected components, each having at least given area
 [[nodiscard]] MRMESH_API FaceBitSet getLargeByAreaComponents( const MeshPart& meshPart, BaseUnionFind<FaceId> & unionFind, float minArea,
     UndirectedEdgeBitSet * outBdEdgesBetweenLargeComps = nullptr );