Demo 2: Sculptured Shapes (patches)

This demo will show the use of PicTrees defined mathematically. First we'll look at a simple polygon. Click on the image icon below. It brings up a PicTree viewer displaying a square polygone (in 3-D) with a picture of an eye mapped on to it (generated in a 256 cubed universe). As in Demo 1, you can view it from different viewpoints and scale factors.

Just as any 2-D curve can be rasterized into a 2-D image, any geometric surface (or solid for that matter) can be "voxelized" into a 3-D PicTree. The object below is the eye image mapped on a bicubic patch (as used in Computer-Aided Design systems to model sculptured surfaces). Is was voxelized into a 256 cubed universe and requires 81K bytes of storage.

The following is the same patch but generated at a higher resolution (a 512 cubed universe). It is stored in 276K bytes.

You may want to display both for comparison of quality.

The object below is the famous teapot (familiar to anyone who hangs around computer graphics shows). It is composed of 32 bicubic Bezier patches. You're probably sick of the eye by now, but to facilitate comparison we once again use it (buy PicGen and you can map anything you want!). Actually, we could have mapped several different images on to the teapot at the same time (different patches) but since we're only using 8-bit color, image quality would suffer. You may note that in several cases the eye is mapped across several patches.