API Reference > core-geometry > CartesianGeometry > Plane3dByOriginAndUnitNormal > altitude altitude Method Return the altitude of spacePoint above or below the plane. (Below is negative) altitude(spacePoint: Point3d): number Parameter Type Description spacePoint Point3d Returns - number Defined in geometry3d/Plane3dByOriginAndUnitNormal.ts Line 211 Last Updated: 20 June, 2023