Ray intersect surface

What is an effective/fast way to find if the ray intresect
surafce.Does OpenGL provide this functionality?
I have lots of surfaces (each surface given by the vertexes,their ordering CW/CCW is not known)

Thanks in advance for the answers!

OpenGL does not provide this functionality, it just draws stuff. Google “Ray Polygon intersection” and you’ll find lots of resources out there. If you want a library that supplies this functionality, try CGAL (http://www.cgal.org/)

It depends on what you actually need the ray intersection for. If you need a fully functional ray intersection test for individual polygons–even the ones off screen and occluded by other polygons–you’ll need a library for that as Pziko suggested.

However, if you’re doing something simpler than that like “which primitive is under my mouse?” that can be done much easier.


This is a page that explains the limited selection support OpenGL provides. You can google other methods like OpenGL stencil selection. I would only use a separate ray intersection library if you really had a good use for it.