API Reference > geometry-core > CartesianGeometry > Ellipsoid > radiansToUnitNormalRay radiansToUnitNormalRay MethodStatic if ellipsoid is given, return its surface point and unit normal as a Ray3d. if not given, return surface point and unit normal for unit sphere. radiansToUnitNormalRay(ellipsoid: Ellipsoid | undefined, thetaRadians: number, phiRadians: number, result?: Ray3d): Ray3d | undefined Parameter Type Description ellipsoid Ellipsoid | undefined thetaRadians number phiRadians number result Ray3d Returns - Ray3d | undefined Defined in core/geometry/src/geometry3d/Ellipsoid.ts Line 670 Last Updated: 13 June, 2024