Try using exponentiated sine waves to perturb water surface normals

[depressed-pho]

The shader currently uses Gerstner wave function for both geometric and normal perturbance, but it might be better to use exponentiated (possibly squared?) sine waves for the latter. This is because the soft edges of Gerstner waves tends to create line-like artifacts of specular light for non-directional light sources.

But it means that I will have to get partial derivations of such a wave function and thus strains my math brain.