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

View-Dependent Tessellation

Most of the examples in this chapter have set the tessellation level factors to constant values (either in the shader or through uniform variables). One key feature of tessellation is being able to compute tessellation levels dynamically in the tessellation control shader, and in particular, basing the amount of tessellation on view-dependent parameters.

For example, you might implement a level-of-detail scheme based on the distance of the patch from the eye’s location in the scene. In Example 9.11, we use the average of all the input-patch vertices to specify a single representative point for the patch, and derive all the tessellation level factors from the distance of that point to the eye point.

Example 9.11. Computing ...