I am draping circles produced by v.circle and other GRASS programs over a DEM in NVIZ, and getting odd results. Depending on the resolution of the region when I start NVIZ, and the polygon size within NVIZ, I get spike-like vectors projecting from the circles, either up and down, north-south or east-west. At higher resolutions I get more spikes, and with smaller circles I seem to get longer spikes. It's not predictable, however -- not all circles get spiked, it seems. Has anyone seen this behavior, and is there a way around it? I'm running GRASS 5.0.0 on Mac OSX 10.2.3.
Many thanks,
Nick Cahill
Dept. of Art History
Univ. of Wisconsin-Madison