OpenGL Programming Guide: The Official Guide to Learning OpenGL, Version 4.3, Eighth Edition

Tessellation Shading

After the vertex shader has processed each vertex’s associated data, the tessellation shader stage will continue processing those data, if it’s been activated. As we’ll see in Chapter 9, tessellation uses patchs to describe an object’s shape, and allows relatively simple collections of patch geometry to be tessellated to increase the number of geometric primitives providing better-looking models. The tessellation shading stage can potentially use two shaders to manipulate the patch data and generate the final shape.