How do I generate Animations on the fly in local scripts?

I was wondering if there is a way in roblox to make keyframes and generate animations with those keyframes via localscripts, I would like to do this so I can develop a system in which the player's feet plant themselves on things like hills using IK.

Sorry, I don't have any code to show you because I have no idea how to go about doing this, if you could show me a snippet of code that generates an animation using keyframes i would appreciate it.

The way I know it there's absolutely no way to generate animations on the fly but there are alternatives.