As Simple as Possible Tessellation for Interactive Applications

A tessellation operator increases the number of nodes in a mesh and can be understood as an upsampling method for polygonal surfaces.

Using real-time tessellation allows the application developer to specify a coarse mesh at the application level, but dynamically add vertices as needed at GPU level. This high resolution mesh may then be used to sample a (visually) smoother surface, eventually displaced using scalar or vector maps.