
Toric X surface
The Toric X surface is generated in two steps. First, in the x-z plane a curve is defined by a standard aspheric profile:

Second, this curve is revolved about a horizontal (x) axis that intersects the z axis at distance Rtoric from the curve. At its vertex, therefore, the surface has curvature c+2a2 in the x direction and 1/Rtoric in the y direction.
Setting Rtoric to infinity or zero allows the toric surface to be used as an acylinder whose axis is parallel to the y axis.
Parameters
- toricR
- Toric radius of curvature Rtoric
- a2, a4,..., a16
- Aspheric coefficients for surface sag
Changing a Toric X surface into a Toric Y surface on the surface data editor is a quick ray to rotate the toric by 90 degrees.