I have a NURBS line which is always composed of 3 points, 3 weights, the knot vector, and is of degree 2.
I need to calculate the length of this line, but I can't find any method online to do so.
It doesn't have to be 100% accurate, converting into a polyline and working out the combined length of the segments would be fine too. Does anyone have any suggestions?
Arc length of a parametric curve is computed typically via numeric integration, such as Runge Kutta method. If you can settle with approxmiation values, then you have at least two ways to get an approximation value. The first way is as you described, convert the curve into a polyline then compute the polyline's length, which will always be a lower bound of the actual arc length. The 2nd way is to compute the length of the control polygon. You can always refine the conreol polygon by knot insertion to get the approximated value closer to actual value.
