Hi there,

I was wondering whether someone can explain the difference between a
spotlight and a cylindrical spotlight to me. The POV-Ray docs state:

> Cylindrical light sources work pretty much like spotlights 
> except that the light rays are constrained by a cylinder 
> and not a cone. 
> .....
> You should keep in mind that the cylindrical light source 
> is still a point light source. The rays are emitted from
> one point and are only constraint by a cylinder. The 
> light rays are not parallel.

If the rays are not parallel and contrained by a cylinder, how is this
different from a spotlight constrained by a cone?
Does this mean that the area illuminated by the light is the same no
matter how far away the surface is? If so, then why do the docs say
that the rays are not parallel?

Confused,

- Lutz
  email : lut### [at] stmuccom
  Web   : http://www.stmuc.com/moray

Post a reply to this message