On 22 Feb at 20:19, Martin Wuerthner <lists@xxxxxxxxxxxxxxx> wrote: > In message <mpro.lh0q170001fc40p8e.tim@xxxxxxxxx> > Tim Powys-Lybbe <tim@xxxxxxxxx> wrote: > > > Time for something on ArtWorks. > > > I think I have at least got the hang of intersections and am > > delighted with this facility for making it easy to do complicated > > drawings. > > > However there is an odd extra point that keeps on creeping in. > > > [...] > > > The odd thing is the additional point of the Intersection on its > > curved section. There is no such point on the curvature of the > > original shield. The two curved parts of the shield are simple > > beziers. This additional point can be a slight nuisance when trying > > to make minor subsequent alterations to the intersected object. But > > if the point is deleted that segment reverts to a straight line. > > > Does this additional point have to be there? > > It does not have to be there but this is how the intersection > algorithm in ArtWorks works. Curves that are not cut through by the > clipping path remain untouched, only intersected curves are modified > to end in the intersection point, but in addition to that they usually > get another anchor point near the intersection. There is no easy way > to prevent this from happening. > > Xara Xtreme did exactly the same for a long time. Version 3.2 still > behaved as ArtWorks and added these extra points (not surprising since > the intersection routines were written by Gavin who also wrote those > used in ArtWorks). Xtreme 4.0 was the first version that used an > improved intersection algorithm producing the optimal result without > any extra points. Many thannks for that answer. I shall rabbit no more! -- Tim Powys-Lybbe tim@xxxxxxxxx for a miscellany of bygones: http://powys.org/ ------------------------------------------------------------ To change, suspend or cancel your subscription go to //www.freelists.org/list/artworks ------------------------------------------------------------