How to repeat noise in given time?

[tgrajewski]

It seems that all examples and tutorials use incrementing time uniform, which grows to infinity slowly.

Is there a way to wrap the time value, so that it the noise repeats itself seamlessly after N seconds?

[redblobgames]

I think many of the demos use time as the rotation parameter, so it's repeating automatically. But if you're not using time for rotation, I think one easy way would be to use sin(time) instead of time.

[stegu]

How to make the rotations repeat depends on how you use the 'time' parameter. You must find a common period for all rotations and wrap the uniform input value to that. If one component of noise uses 2*pi*time for the 'alpha' rotation, another 2*pi*time*0.1 and a third uses 2*pi*time/15.0, all expressions will attain an even multiple of 2*pi at time=30, thus you can send a uniform 'time' that wraps at 30 seconds to avoid the bad precision with large values for 'time'. If you use factors that have common primes, like time*2*pi/2^k, 0<=k<=N, all rotations will wrap at time=2^N. Noise is often used as a sum of components that scale by some power series, 2^k or sqrt(2)^k, both in terms of the spatial and the temporal scaling (size and speed).