When Random Numbers Are Too Random: Low Discrepancy Sequences
Random numbers can be useful in graphics and game development, but they have a pesky and sometimes undesirable habit of clumping together.
This is a problem in path tracing and monte carlo integration when you take N samples, but the samples aren’t well spread across the sampling range.
This can also be a problem for situations like when you are randomly placing objects in the world or generating treasure for a treasure chest. You don’t want your randomly placed trees to only be in one part of the forest, and you don’t want a player to get only trash items or only godly items when they open a treasure chest. Ideally you want to have some randomness, but you don’t want the random number generator to give you all of the same or similar random numbers.
The problem is that random numbers can be TOO random, like in the below where you can see clumps and large gaps between the 100 samples.
