[PD] GEM- simple img texturing into a circle

[Oded Ben-Tal]

> Hello all, I am trying to do something which should be fairly easy: I am
> trying to see a circle that let's through an image that is behind it. (As if
> through a telescope...)

Why not render the picture on a square/rectangle, and put a 'hole' in 
front of it (for instance a cylinder: make it very wide, thick, and 
short. rotate 90 degrees so we are looking 'throught' it). moving the 
picture & your 'hole' in coordinated fashion back and forth could create a
telescope like effect, no?