API Reference > geometry-core > CartesianGeometry > Ellipsoid > radiansToFrenetFrame radiansToFrenetFrame Method Evaluate a point and rigid local coordinate frame the ellipsoid at angles give in radians. The undefined return is only possible if the placement transform is singular (and even then only at critical angles) radiansToFrenetFrame(thetaRadians: number, phiRadians: number, result?: Transform): Transform | undefined Parameter Type Description thetaRadians number longitude, in radians phiRadians number latitude, in radians result Transform optional transform result Returns - Transform | undefined Defined in core/geometry/src/geometry3d/Ellipsoid.ts Line 618 Last Updated: 13 June, 2024