i would like to draw just the intersection of poligons

thank you in advance.
How can I draw jast the intersection of few polygons or spheres?

Hi !

If you mean the intersection “volume” of two spheres then you need to add boolean support to OpenGL, there are examples out there on how to do boolean operations in OpenGL, there are also libraries that takes two meshes and create a new one as a result of a boolean operation.

What you can do in openGL is to use clipping planes to cut away parts of an object, like slicing a sphere in two parts for example but that is all you have built into openGL.

If this is wwhat you need you can find lots of information if you try google.