A slight catch on the technical side, is that a curved path might crossover to unwalkable territory even if the linear spline did not. Since you've already padded/enlarged those regions with extra space anyway (Post# 05-30-2008 10:49 PM) , I think it'll be ok.

You might enjoy this link to deCasteljau's algorithm, it is a pretty elegant geometric-based algorithm for drawing bezier curves.

http://en.wikipedia.org/wiki/De_Casteljau's_algorithm#Geometric_interpretation

I'm guessing the path-smoothing algorithm takes place in screen space? One thing that has always bugged me is that (I think) the perspective transform of a bezier curve is not a bezier curve in screen space. However, (I think) a NURBS does map to another NURBS, when perspective transformed. This is only relevant if you're interested in decoupling pathfinding from camera positioning. (IE paths are all precomputed in world space, then projected to various screen spaces depending on which camera is active).

Cool work