I’m

still having some difficulty applying the nurbs library .net to our data. My

spline is defined as:

EDGE_821431:

Knot vector: 0, 0, 0, 0, 0.57351624087487, 0.57351624087487, 1, 1, 1, 1,

Start: 37.7678802732627 -122.405748663195 -27.1726756611392.

Internal Points:

37.7676243108484 -122.405549798135 -26.951927961973,

37.7674507412853 -122.405477146244 -26.494755251341,

37.7669002053626 -122.405412377091 -26.292554533398,

37.7666682800705 -122.405385499246 -25.9765675483037,

End: 37.7664396492698 -122.405323857491 -25.8969367061305.

Using some internal tools, I’ve

determined that the length of this curve should be around 166 meters.

My approach (naive) was to create

a polyline by “walking the curve” in 0.1 increments (parameter space) and

adding up each segment of the polyline. I get around 141m (off by about 15%).

Of course there will be a difference between the polyline approximation and the

“true” length of the curve, but I was hoping for a more accurate value. Do you

have any recommendations?