static [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * DeleteTrianglesInPolygroup ( [UDynamicMesh](API\Runtime\GeometryFramework\UDynamicMesh) * TargetMesh, [FGeometryScriptGroupLayer](API\Plugins\GeometryScriptingCore\GeometryScript\FGeometryScriptGroupLayer) GroupLayer, int PolygroupID, int & NumDeleted, bool bDeferChangeNotifications, [UGeometryScriptDebug](API\Plugins\GeometryScriptingCore\GeometryScript\UGeometryScriptDebug) * Debug )