The initial goal of the prototype is to explore a way to draw big trees and still have the ability to zoom and scroll at interactive speeds. The prototype is written in cross-platform C++ and uses OpenGL to render. It adapts a common computer graphics technique called level of detail (LOD) to control to amount of data being drawn at once. This shows promise—the current implementation can smoothly navigate a 50K taxon tree on a laptop. While not tested yet, it should be possible to load a tree with over 500k taxon on a high-end visualization system. The current challenge is developing different levels of detail that are useful to the user. The current version represents a clade as a box that encompasses all the children of a given node. As the user zooms closer to the tree, each node of the tree is visited in a depth first search. At each node, a decision is made to draw the box, or draw its children. The tree traversal stops when a box is drawn, or when a leaf of the tree is reached.

Source code: http://svn.iplantcollaborative.org/iptol/visualization/tv_prototype
Windows binary: download
Mac binary: download

Screen shots of the current version: