Nurbs and control points

OpenGL OpenGL: Advanced Coding
1

Hello,

This is my problem: I have a set of vertices which are basically waypoints, similar to waypoints in a flight sim or space game. Instead of drawing a line between each pair I want a nice smooth curve which interpolates each point. (from the start point through each point to the end point)

Ive tried using the GluNurb code, and unless I dont understand it correctly, I can only get the spline to interpolate each point by duplicating control points, and I also only seem to be able to have a maximum of 8 control points. I dont really understand the knots but what I do with them is to set the first half to 0 and the second half to 1 so that the spline always starts at the start and ends at the end.

So basically my problem is this… I only seem to be able to use 8 control points (a line is not drawn if more are used) and I dont know how to get the spline to interpolate each point properly.

Hope someone can help

David

2

You haven’t to understand knots to make them work ;-).Their sence is somwhere deep in math(b-spline interpolation). All you need is to create array like this
(0,0,0,1,2,3,4,5,6,7,8,9,9,9)
for 9 knots. Note that first 3 and last 3 are same.
i dont uderstand thier meaning too, but i marked, that if you’ll multiply all that knots or increase/decrease them curve will not change.