Re: [brlcad-devel] A question about curve-curve intersections

[Clifford Y. <cli...@gm...>]

On Thu, Jun 27, 2013 at 9:42 AM, phoenix <284...@qq...> wrote:

> Hi,
>
> These days I'm working on computing NURBS curve-curve intersections, and
> have a problem:
>
> As one type of ON_X_EVENT is ccx_overlap, and we need to decide whether
> the intersection event is an overlap event or just an intersection point.
> Currently I use two Newton-Raphson iterations from two different starting
> points (two end-points of the sub-divided interval), and see whether they
> converge to the same point. If not, the sub-curve between them will be
> sampled and calculate the distance of the sampled points to the other
> curve, to see whether they overlap. But it's not a good solution because in
> some cases when they overlap but the two iterations also converge to the
> same point.
>

Hmm.  What literature have you already seen on the topic?  Do

http://cagd.cs.byu.edu/~tom/papers/bezclip.pdf

and/or

http://cagd.cs.byu.edu/~tom/papers/fatarcs.pdf

offer any useful insights?

CY