View Full Version : Rendering transparent "pie" area

08-25-2011, 05:12 PM
First I want to thank MaxH for helping me previously about rendering a triangle for my aircraft application.

I am still working on the application but now I need to render a circular region (spanning +- 110 degrees) from the nose of the aircraft.

Any help on how to accomplish this would be greatly appreciated!


08-26-2011, 01:42 AM
There are in general two ways to draw circles; Draw one polygon, and discard all fragments that are further from a given centre than a given radius. The other way is to draw several triangles sharing the same vertex in the centre of the circle, where the rest of the vertices are all positioned along the edges of the circle.

08-26-2011, 03:16 PM
You could write your own function which would be fairly easy,
or you could you use gluPartialDisk (). See the link below ...