I used to have this book called "Optical Designs in Motion with Moiré Overlays", thick pages with transparent pattern overlays you'd slide around to watch the interference. My brother said "you should make a web app out of -that-," so here it is.

Click/tap to drag the top layer around. Double-click/tap to open settings where you can change colors, patterns, and effects. The "blur" effect is especially fun, it's a blur->posterize chain that makes the interfering patterns merge into variable blobs. That's the "emergent field" part. Hit "export preset" to copy your settings into a shareable link.

here's another fun one: https://mcbgl.vercel.app/?p=eyJ2ZXJzaW9uIjoyLCJzZXR0aW5ncyI6...