Curl noise

[jasonwebb]

Similar to #43, this is significant enough of a topic to deserve a more detailed section. There aren't as many resources available, but it's so beautiful that I think it is worth the extra info.

• Good for approximating advection and vortices
• Original paper by Robert Bridson et al (PDF)
• https://petewerner.blogspot.com/2015/02/intro-to-curl-noise.html
• Bitanged noise by Ivan DeWolf may be computationally more efficient, but largely unknown.
• Code links:
  • Curl Noise VOP node in Houdini
  • Available in Unreal 5