the permutation texture is simply a 256x256px image, with random 0>1 values for each of the RGBA channels in each pixel.

Like the example in this post.

https://machinesdontcare.wordpress.com/2009/06/23/

You should be able to just download it and use it as-is.

Hope that helps.

a|x

]]>Your code uses this 2D permutation texture:

uniform sampler2D permTexture; // Permutation texture

Can you give us a hint on where to obtain a texture for this? I looked at Gustavson’s noise implementation that you referred to as a source; it gives a 1D pre-initialized array, and then computes the 2D array from that. But you seem to have the 2D texture precomputed. Can I download it?

Thanks,

Lars