  We present GLSL implementations of Perlin noise and Perlin simplex noise that
run fast enough for practical consideration on current generation GPU hardware.
The key benefits are that the functions are purely computational, i.e. they use
neither textures nor lookup tables, and that they are implemented in GLSL
version 1.20, which means they are compatible with all current GLSL-capable
platforms, including OpenGL ES 2.0 and WebGL 1.0. Their performance is on par
with previously presented GPU implementations of noise, they are very
convenient to use, and they scale well with increasing parallelism in present
and upcoming GPU architectures.
