I have returned to developing my povwriter for processing-1.5.1 (which I am developing in tandem with a version for processing-2.0). The most recent added features for version 0.83 is the addition of ArcBall manipulation of the sketch, and a MouseWheel "zoom" feature that works by adjusting the scale. For the ArcBall there is an ability to constrain the rotation to one of the 3 primary axes (x, y, z). Tested as working on linux ( calling for feedback from windows/mac users), requires an installed version of povray, preferably 3.7 beta rc5.