Algorithm of OpenGL tessellator

Hi all,

I need to write a paper about tessellation at my university and as chapter 1 I need to describe/explain how the “standard” tessellation works. Since OpenGL is open source, I suppose also the algorithm/maths behind it are also free. Maybe it is written somewhere but I didn’t find it.

Thx for any help

OpenGL is not open-source. OpenGL is API specification open to anybody.
Currently tesselation in OpenGL is available only as vendor specific extension AMD_vertex_shader_tesselator.

Wow, thats new information :slight_smile:

Do you happen to know where can I find additional information on this theme? Basically I have to describe how video cards (GPUs) display primitives (spheres,etc) using triangulation. What algorithms are used, etc. First I’ve thought the answer is in the Catmull-Clark subdivision surfaces, but I was pointed out that that algorithm is used for mesh refining, not for approximations with lower polycount meshes.

Hardware GPUs only display triangles.
Any other primitive must be described with triangles by the CPU program.

Maybe you had something else in mind, like GLU tesselation ?

There is an open source implementation of GLU in Mesa3D: