A straightforward way to leverage shaders for animation is to simply transform the vertices within the vertex shader based on some time-dependent function. The OpenGL application supplies static geometry, and the vertex shader modifies the geometry using the current time (supplied as a uniform variable). This moves the computation of the vertex position from the CPU to the GPU, and leverages whatever parallelism the graphics driver makes available.
In this example, we'll create a waving surface by transforming the vertices of a tessellated quad based on a sine wave. We'll send down the pipeline a set of triangles that make up a flat surface in the x-z plane. In the vertex shader, we'll transform ...
