I’m trying to add some randomness to rotational fx, so that rotations don’t repeat so much.
I’ve got a Slit Scan that rotates, following a slow LFO. How would I make it not follow the same path over and over?
I’ve been experimenting with adding random LFOs, but they’re always too fast. Can’t figure it out, tried a bunch of things like adding a slow clock, smooth num fx and so on. Kinda stumped, anyone know a way?
Thanks!
One simple trick to fake randomness that comes to mind:
Have a second LFO modulate the speed of the first LFO. It usually has to be subtle. Set the low and high points so it shifts slightly between 10% of the “original speed” or so. That way it looks like it is sometimes slightly faster, sometimes slightly slower. By adjusting the exact settings you can make it “seem” un-repetitive.
You can either just use a sine wave as the modulator, or for slightly less obvious patterns, use waveform and build it with maybe 5-6 various highs, lows and distances between them. That way the speed-change will seem random.
(This trick of course won’t work if your animations are synced to music etc)
(I’m hopeful someone else has a better solution because this is a hack)
Thanks, made me take a step back to what I’m actually after. Random modulation probably won’t work at all, and made my question convoluted.
More simply put, what I’m after is a way to rotate fx. If there relative coordinates inside the fx, that would do the trick. So one LFO would rotate the slit scan’s angle, and another one would slowly rotate the entire slit scan fx (but not the layer).
Doh! Random is entirely wrong, I want a circle. A slit scan that does its thing and then another rotation applied to it, from outside. I’m still thinking there could be some way of achieving it by modulation, but maybe Math is the way rather than combining LFOs?
I can’t wrap my head around what you’re trying to achieve, but: Have you considered using Gemini or GPT to vibe code an ISF that does exactly what you want?
I’m having excellent results using Gemini to create all kinds of shaders and tools I need. Also to update existing effects that I’d like to improve/adapt. They understand ISF code instantly and generates new ones in 10-30 seconds. I don’t know anything about coding ISF but generally takes me between 5-10 iterations (conversational, discussing the effect, any issues and problems with early versions) before Gemini nails a perfectly functional ISF.
They might also actually understand what you’re trying to achieve faster and better than me 
Good tip, thanks!
But I’m already way past the point where I’m spending too much effort on a relatively minor thing. Might take it up again if I stumble on smth in the future, but giving up for now.
(Sry for the confusion I created btw. I realised after you replied that asking about ‘random’ was the wrong question in the first place. I’d created the ‘random-problems’ while trying to get rotation(s) to do what I wanted. Rabbit-hole thing, getting caught up in fixing that ‘solution’ instead of finding smth that’d work for my real issue)
Hey if you use shadertoy, search BHS, thats my user name, all my shaders are made from gemini as well
I don’t use shadertoy, sry. At least not yet…. I’m not very deep into technical aspects of building shaders and such, but always interested in anything that will do interesting visual things to my audio / other input!