Page 1 of 1

Constrained Delaunay Triangulation (sweep-line)

Posted: Sat Jan 23, 2010 3:43 am
by zzzzrrr
Poly2Tri, A constrained Delaunay triangulation library, is now available in C++ and Java:
http://code.google.com/p/poly2tri/

A few videos for your viewing pleasure:
http://www.youtube.com/watch?v=Bt1TYzzr2Rg
http://www.youtube.com/watch?v=Gdceq4fO ... re=related

Re: Constrained Delaunay Triangulation (sweep-line)

Posted: Sat Jan 23, 2010 4:07 pm
by raigan2
This is maybe OT, but at 1:05 in the first video there's a pretty cool effect where dense features are highlighted in pink, and as you zoom in (and they spread out) the highlighting diminishes. How was this done? Drawing an additive-blended nearly-transparent point at each vertex is my only guess..

It seems like a really effective method for showing where features are too dense to properly see at the current zoom level.

Re: Constrained Delaunay Triangulation (sweep-line)

Posted: Sun Jan 24, 2010 12:53 am
by obidobi
raigan2 wrote:This is maybe OT, but at 1:05 in the first video there's a pretty cool effect where dense features are highlighted in pink, and as you zoom in (and they spread out) the highlighting diminishes. How was this done? Drawing an additive-blended nearly-transparent point at each vertex is my only guess..

It seems like a really effective method for showing where features are too dense to properly see at the current zoom level.
Not really an effect more a feature :). Due to how those polygons are generated we get clusters of vertexes at certain areas. I just draw each vertex in the polygon as a red pixel.
The video size is reduced and compressed by YouTube so single pixel vertexes are barely seen, when they are grouped liked that not even YouTubes compression algorithm can remove them :). So when zooming in the vertex density gets smaller to a point where the compression makes them invisible again.

Re: Constrained Delaunay Triangulation (sweep-line)

Posted: Sun Jan 24, 2010 2:24 pm
by raigan2
Thanks!