API Reference > geometry-core > CartesianGeometry > IndexedXYZCollectionPolygonOps > splitConvexPolygonInsideOutsidePlane splitConvexPolygonInsideOutsidePlane MethodStatic Split a (convex) polygon into 2 parts based on altitude evaluations. POSITIVE ALTITUDE IS IN splitConvexPolygonInsideOutsidePlane(plane: PlaneAltitudeEvaluator, xyz: IndexedReadWriteXYZCollection, xyzPositive: IndexedReadWriteXYZCollection, xyzNegative: IndexedReadWriteXYZCollection, altitudeRange: Range1d): void Parameter Type Description plane PlaneAltitudeEvaluator any PlaneAltitudeEvaluator object that can evaluate plane.altitude(xyz) for distance from the plane. xyz IndexedReadWriteXYZCollection original polygon xyzPositive IndexedReadWriteXYZCollection array to receive inside part (altitude > 0) xyzNegative IndexedReadWriteXYZCollection array to receive outside part altitudeRange Range1d min and max altitudes encountered. Returns - void Defined in geometry3d/PolygonOps.ts Line 694 Last Updated: 12 June, 2024