Collision, sphere moving down a slope?

[detzel]

I want to be able to move a sphere down a slope...not the laws of physics are pretty simple but I can't see how the ball will know which way to move...should I just move it down and see if it's elevation is less then it was before? Any ideas will be appreciated.

[mmcoder]

Here's one way to look at it http://www.gamedev.net/reference/articles/article1026.asp

not a lot of code in there unfortunately