I'm trying to use Brownian motion to create a group of random moving particles.http://jsfiddle.net/J75Em/16/
So far I've got the particles moving randomly but I'm not sure how to set the forward direction to make it look more natural.
I've tried to use the change in x and y-axis to calculate rotation using atan, you can see this by uncommenting rotate but this doesn't seem to perform well.
Is this the right approach for this type of movement? thanks.