Here is @Stefan_Petrick 's code for an 8x8 matrix on an Adafruit 60 LED ring. Looks killer! I love it when you try random code on new rigs and you find a gem.
Cool!
I like to take 2-D code and run it on a ring or a strip, telling the XY mapping function to that the matrix is serpentine / boustrophedon layout, ie back and forth rather than just in row order. That makes the end-of-row bits reflect back and forth against each other, and makes for a smoother pattern.
I’m not making sense here I suspect, but try changing your XY mapping to serpentine and you’ll see what I mean. (Example XY matrix code with this setting available is in the Examples folder of FastLED 2.1…)
Often times, changing a mapping, e.g. running a 2D pattern on a 1D setup, or running a 1D pattern on a 2D or 3D setup, etc… creates some fantastic effects 
Cool, I didn’t recognise the concept in the pattern at the beginning! Being surprised by interations of the own code… feels awesome!