Noise Alpha Attenuation

Something else we can do is use diamond-square noise height maps (due to Lucky) to create an organic kind of randomness to the aurora. Not really sure how much mileage we get out of it though... The alpha channel becomes

Alpha = 255 * Noise(s, t) * EndpointInterp(s) * HeightInterp(t);

with all the noise and interpolation functions having a domain and range of [0, 1]. Here, s represents the parameter moving along the skeleton spline and t represents the value of the distance from the pixel to the skeleton spline divided by maxdist(s).

Here, you can see the difference between having noise and not having noise. I might try doing a brightness adjustment with the noise instead.