Constrained Delaunay Triangulation (sweep-line)

zzzzrrr
Posts: 10
Joined: Mon Apr 16, 2007 7:11 pm
Location: Washington, DC

Constrained Delaunay Triangulation (sweep-line)

Post 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
Last edited by zzzzrrr on Sat Jan 23, 2010 4:44 pm, edited 1 time in total.
raigan2
Posts: 197
Joined: Sat Aug 19, 2006 11:52 pm

Re: Constrained Delaunay Triangulation (sweep-line)

Post 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.
obidobi
Posts: 1
Joined: Sun Jan 24, 2010 12:42 am

Re: Constrained Delaunay Triangulation (sweep-line)

Post 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.
raigan2
Posts: 197
Joined: Sat Aug 19, 2006 11:52 pm

Re: Constrained Delaunay Triangulation (sweep-line)

Post by raigan2 »

Thanks!