Random Walk generates the following:
Random walks: a particle on a random walk moves in an entirely random direction at each step, until it hits the boundary of the grid.
Classic random walk patterns: particles start anywhere on the boundary, and randomly walk until they hit either the center of the grid, or another stopped particle.
Inwards random walk patterns: the reverse of the classic random walk pattern - particles start at the center of the grid and randomly walk until they hit the boundary or another stopped particle.