What is parallel and perspective projection in the volume rendering and are these features supported in VolumePro hardware?
Volume rendering is the projection of a three-dimension data set onto a two-dimensional image. Parallel projection means that the rays being cast through the volume are parallel to each other. This is equivalent to placing the eye of the viewer at an infinite distance from the volume. In perspective projection the viewer is at a finite distance from the volume of interest. The size of a perspective projection of an object varies inversely with the distance of the object from the center of projection. This provides the foreshortening that is a familiar part of three-dimensional art and photography. VolumePro® 500 hardware supports only parallel orthographic projection. Perspective can be achieved in software but at the expense of performance. Future generations will support perspective projection in hardware.
