AnalyticalGraphicsInc/cesium — pull request #2035 by mramato (2014-08-07 02:06:31+00:00)
Title: Use PolylineCollection for time-dynamic polylines

In order to keep feature parity between static and time-dynamic polylines, PolylineGeometryUpdater was using PolylineGeometry to render lines that were changing every frame. Obviously this generated a lot of garbage and would kill performance when using a lot of time-dynamic lines (like the d3 demo does). In order to improve performance, I've updated the dynamic lines to use PolylineCollection instead; which greatly improves performance.

The only feature PolylineGeometry has that PolylineCollection lacks is per-vertex colors; but since the DataSource layer doesn't expose that feature yet; this is okay for now. Of course when we have dynamic buffers, this problem should just go away.