John Shier and Doug Dunham

Retired Professor of Computer Science
Department of Computer Science, University of Minnesota Duluth
Duluth, Minnesota, USA

Artists have employed metamorphosis or transitions to patterns in order to obtain interesting aesthetic results. Perhaps the best known examples are M.C. Escher's Metamorphosis I, II, and III. We use this transformation idea to create new images with computer technology. Continuous random functions are the basis for our calculations, and these are then modified by continuous transitions, from 0 to 1 for example. In order to render an image in a reasonable amount of time, the random functions should be calculated efficiently. The use of Perlin noise is one solution to this problem. These functions can be used to vary color, position, orientation, and other geometric properties of subimages from left to right or top to bottom.

Order and Chaos
25 x 38 cm
Color Print

One of our ideas concerns transitions from order to disorder. Going linearly from one to the other can seem jarring, so we use modifying functions that are 0 for some interval, then sweep up to 1 for an equal interval. This is the form of all the modifying functions in this image. The orientations of the squares start out upright and the positions are regular, then they become more random on the right. Similarly, the edges start out straight then become curved. There are two sets of paths through 3-dimensional RGB color space, the paths of one set start on the left at white and the other at black. Then they proceed toward random mid-range colors, so that at the right the color distributions of the two sets become the same.

Night into Day
25 x 38 cm
Color Print

This scene has a background which is black at the left, passes continuously through grayscale at the center, and becomes white at the right. It was found that the grayscale needed both x and y gradients. Black birds and white stars are placed on this background, with the stars invisible at the right and visible at the left, and vice versa for the birds. The result is stars fading at daylight, and birds disappearing into the night.

The yucca plants have varied shapes, but are 50% gray so are visible everywhere in the bottom half. The sizes of the plants decrease and their number increases toward the midline, giving a perspective effect. The sun and moon enhance the scene. This image was inspired by Escher's "Day and Night".