The only way I would know is to linearly search each nurb. But I'll ask some friends I have, see if they can offer any advice.

]]>As for finding the intersection, there isn't any formula you can use. That's because there is no formula for a cubic nurb, besides knowing where the control points are.

]]>A nurb is a straight line with control points. The control points work like gravity. The closer it is to the line, the more it pulls it. So placing a control point above a line will make it arc up, almost like -x^2. Placing one above and below the line gives you a cubic nurb, it looks like a cubic polynomial.

You can move the control points to where ever you want, and it thus makes it easy to draw specific curves. Very useful for modeling surfaces of things like cars.

]]>If the first one, there's a cubic formula that you can use. It's very ugly, but it's usable. It would probably be easier to factorise it though, if you can.

If the second one, you just take one of the curves away from the other one to get a problem similar to the first case.

]]>thanks..]]>