Musgrave and Voronoi Nightmares

I know that Procedural textures aren’t used as much as image-based textures, but I’m sure they have several uses on their own. You’ve all probably heard of Musgrave and the ever so famous Voronoi procedural textures, but what are they? The Blender Wiki refers to these two textures as one of the most flexible and versatile forms of Procedural textures. The only problem is that there isn’t enough documentation on how one can use these two effectively. I would have taken my usual approach of experimenting with every button and slider but unfortunately I don’t enough time for that.:spin:

So please if anyone out there knows any links on where I could find in-depth tutorials on these two procedural textures please help me out.

…or…

If any one can define the following terms and what they mean in blender please comment below::smiley:

Musgrave

  • Hetero Terrain
  • fBm
  • Hybrid Multifractal
  • Ridged Multifractal
  • Multifractal
  • Lacunarity
  • Octaves
  • Offset and Gain
  • Nabla

Voronoi

  • Minkovsky
  • Chebychev
  • Distance Squared
  • Actual Distance
  • Feature weights
  • Worley Sliders
  • Nabla

And please do so in less Blender-wiki-ish language because its a bit hard to understand. Thanks in advance.:smiley:

Nabla

I am especially curious what this is. I have played with it many times and seen 0 change, even when using extremes.

Same here, especially the Nabla value, which is common to most Procedural textures, won’t budge. And the wiki was even more confusing.

About nabla see: http://www.tutorgig.info/ed/Skew_gradient

Nabla is simply the discrete “epsilon” to calculate a gradient. It’s used for bumpmapping.

e.g. GradientNoise(x) = (Noise(x+eps) - Noise(x-eps)) / eps

for a correct theoretical calculation, eps (that nabla) should be smaller than the expected variation of the noise. For a practical use a bigger eps can be useful to avoid antialiasing issues if the noise varies too fast. (fast variation = too many octaves)

For a rendering engine this translates to: choose an eps as small as possible (0.001) but if your noise varies too fast and you get antialiasing artifacts then increase it. Or better: don’t change it because it’s too difficult to be tuned since the result is almost the same. Or again better: don’t expose it to users because it’s too complicated and changing it does not change the image in 99% of all situations.

About the wiki: there are many users who are FOSS purists but almost noone of them donate 10 hours of their time to improve the wiki manuals.

Thanks Faxrender (cool name by the way), I didn’t know that Nabla had this much math in it. That was helpful though.