The 2D OpenSimplex noise is using the new normalized-expanded-vertex-figure gradient set, but the 3D noise is still using the old skewed-expanded-hypercube gradient set. Updating the gradient set should improve isotropy throughout all three dimensions.

I will add this in, and compute the new normalization factor for it.

Sounds interesting... I'm assuming this won't have any effect on anything existing because RTG isn't using 3D noise yet. Is that right?

RTG is using 3D noise to generate the block arrangement patterns on the surface, so that steep slopes don't "stretch" the patterns.

So, fewer predictable patterns and direction biases in the surface patterns?

Any progress to report @KdotJPG ?

Going to include this with the new biome system once that's finally ready.

EDIT: Since that'll require some additions to the noise generator anyway.

Added in 2db7827