I basically use a scalar to dampen the particle. This didnt work to well on say a sphere surface.also air friction I use velocity2 which I then dampen and use to subtract from velocity. It works well though I found that i also have to scale the friction by the length of the inverse of the spring length. This is fine as its effectively a constant. It also means I have to normalize the velocity derived from the verlet (ouch). This was because I move from a non-verlet method where changing velocity was pretty straightforward
I'm just looking for suggestions ? I would not mind removing the normalize for airfriction, and be a bit more efficent
andi