The tool has two key capabilities important to 3D interpretation - absolute control of 3D cursor motion in a workspace to within thousandths of an inch, and the ability to present data attributes as touch properties to the user. The second challenge was to create a viewing environment that provides depth perception and enables the user to navigate in real time. Some workstation vendors now deliver 3D stereo-capable displays, which utilize shutter glasses and frame sequential display techniques to create a 3D image. Many of the existing interpretation applications now include 3D viewing modules, which utilize these displays. However these can take from several to dozens of seconds to repaint the screen after a change, which is certainly not interactive.
True interaction is only possible where the view update is sub-second, aka real time.
Based on our experience with other 3D modeling applications, we chose an IBM Intellistation Z-Pro, which is a Windows NT workstation with dual Pentium processors and an advanced graphics accelerator from Intergraph. The remaining challenge was to build a software application to tie these pieces together, and enable a user to perform 3D interpretation. As the name suggests, VNP plugs into existing environments, extending them to provide fast, intuitive 3D interaction with volumetric data. The program provides interactive 3D stereoscopic visualization and haptically-enhanced selection, evaluation and modification of volumetric data.