API Reference > geometry-core > CartesianGeometry > Ellipsoid > radiansToPointAndDerivatives radiansToPointAndDerivatives Method Evaluate a point and derivatives with respect to angle on the ellipsoid at angles give in radians. "u direction" vector of the returned plane is derivative with respect to longitude. "v direction" vector fo the returned plane is derivative with respect ot latitude. radiansToPointAndDerivatives(thetaRadians: number, phiRadians: number, applyCosPhiFactor: boolean = true, result?: Plane3dByOriginAndVectors): Plane3dByOriginAndVectors Parameter Type Description thetaRadians number longitude, in radians phiRadians number latitude, in radians applyCosPhiFactor boolean selector for handling of theta (around equator derivative) * if true, compute the properly scaled derivative, which goes to zero at the poles. * If false, omit he cos(phi) factor on the derivative wrt theta. This ensures it is always nonzero and can be safely used in cross product for surface normal. result Plane3dByOriginAndVectors optional plane result Returns - Plane3dByOriginAndVectors Defined in geometry3d/Ellipsoid.ts Line 552 Last Updated: 12 June, 2024