API Reference > geometry-core > Curve > RegionOps > polygonXYAreaDifferenceLoopsToPolyface polygonXYAreaDifferenceLoopsToPolyface MethodStatic return a polyface containing the area difference of two XY regions. Within each region, in and out is determined by parity rules. Any face that is an odd number of crossings from the far outside is IN Any face that is an even number of crossings from the far outside is OUT polygonXYAreaDifferenceLoopsToPolyface(loopsA: MultiLineStringDataVariant, loopsB: MultiLineStringDataVariant, triangulate: boolean = false): Polyface | undefined Parameter Type Description loopsA MultiLineStringDataVariant first set of loops loopsB MultiLineStringDataVariant second set of loops triangulate boolean Returns - Polyface | undefined Defined in core/geometry/src/curve/RegionOps.ts Line 408 Last Updated: 13 June, 2024