Because that's what I currently want to achieve, but I don't want to use rigidbodies because I need to have more control over physics. My character controller is on a down ramp but it's not sliding down. Is there a way to do that without using rigidbody?
I don't konw what the other guys who are commenting on your question are on about- you do NOT have to use rigid body simulations. In fact, unless you want your character to have physics applied all the time, it's pretty much a waste of time and processing power.
Adding slide velocity is just as easy as making a 'jump' work. All you have to do is apply downward velocity for gravity and forward velocity in the direction the slope would have you slide. It really is that simple... I'm not sure why so many things get overcomplicated.
For example- in super mario world, you could slide down hills. do you think they used physics simulations for that? I don't think so :)
answered Jul 25 '11 at 06:41 PM