The surface is a tire shape object. Rotate the circle or other secondary curve around the specified axis. Cartesian denotation in the surface of the surface can be remembered as the following form: ┌ ________________ ┐2 │ / x y │ z│r - / (-) 2 (-) 2 │ (-) 2 = 1 │ √ RX RY │ r └ ┘ ┘: r is a given offset value. The parameters of the annulus indicate similar to the ellipsoid surface, but the range of angles is extended to 360 °. By using longitude θ and latitude φ, the annulus to satisfy the following equations: x = rx (R Cosφ) cos θ -π ≤ φ ≤ πy = r (R COSφ) sin θ -π ≤ θ ≤ πz = rzsinφ
