# Curl Noise, Demystified

tutorial

In my recent post on mapping Perlin noise to angles, I was put on to the subject of Curl noise, which I thought I understood, but did not. I figured out what Curl noise really was in a subsequent post and then posted my earlier incorrect (but still interesting and perhaps useful) concept of Curl noise in yet another post. Although I kind of understood what Curl noise was at that point, I wanted to give myself a more complete understanding, which I usually do by digging into the code, making sure I understand every line 100% and seeing what else I can do with it, trying to make multiple visualizations with it to test my understanding, etc.

# Curl Noise

experiments

My last post on Perlin noise wound up on hitting Hacker News, which generated an enormous amount of views, and a fair number of comments – here, on Twitter, and on HN itself. Of course, there was the usual eye-rolling, condescending, “why doesn’t he just do ….? that would be the obvious approach” kind of comments there, but a fair amount of actual helpful ideas, explanations, and links. One thing that came up over and over was the idea of using curl noise. So, when I got a chance, I went ahead and used curl noise.

# Mapping Perlin Noise to Angles

tutorial

A common use case for Perlin Noise is to create some kind of flow field, and a common way to do that is to map the noise value at a particular location to an angle from 0 to PI * 2 radians (0-360 degrees). Above you can see an example of this. But there’s a problem with this logic. Can you see it in the above image?

# Pillar of Noise

I could not be happier about the way this turned out. I could play with this for hours. Which is to say, I’ve been playing with this for hours.

# 7 Days of Code : July ’21 : 07. Divide

https://7daysofcode.art/

I spent WAAAAAAAY too long on this last weekend. I was possessed. It was fun. The code is hideous. Microcomps? Too bad they don’t do anything. Would be fun to build this out a bit. Clean up the code and modularize things, get them animated and maybe some bit of interactivity. But I doubt I’ll be doing that any time soon.

# Canvas Filters and Particles

experiments

I have to admit, after yesterday’s excitement over discovering Canvas filters, and after digging into them a bit to write the last couple of posts about them, I was somewhat underwhelmed. They didn’t seem as exciting as I initially thought they would be. But had another go with them today, and now I am a believer.