There are any number of examples on the web. Have you done a search? Try Google with "B-spline" and dig in. (You've got about 6.5 million hits to work with.) Ditto with NURBS curve. Here's a couple of results: http://mathworld.wolfram.com/B-Spline.html http://web.mit.edu/hyperbook/Patrikalakis-Maekawa-Cho/node17.html