Support fresnel lens

[zumpchke]

Can you support fresnel lens?

[CodeFHD]

Do you require any specific kind of features?
Like spherical lenses only or aspheric too? Circular outline or also square?
Import from an optics design file like the currently supported .zmx? (In that case I need example files of course)

Or do you just want to generate "any" Fresnel lens for now without specific requriements?

Asking because I have yet to consider how to offer the settings in the UI.