The SOFT RATS project was started by me in 1994 in California Institute of Technology with Jim Kajiya as a driving force "of great pitch and moment". Known under the bleak name RAY, it matured into RATS, which means RAy Tracing System, and lots of other things, too (`rats' included). RATS does modeling, rendering and animation of convolution surfaces, it also provides a transparent access to the underlying operating system. RATS can live on almost any UNIX machine, prefers the X Windows environment. RATS is much faster than POVRAY, almost always as fast as Rayshade; RATS is friendly, helpful and we had a lot of fun together. It also has a baby brother (MICE), which is compiled with a single float precision to conserve memory (really).

RATS Version 7.32 amounts to nearly 60,000 lines of C-code. RATS has been compiled and tested in various flavors of UNIX operating system, e.g. HP-UNIX (Hewlett Packard), OSF1 (DEC Alpha stations), SunOS 4.X (Sun SPARC Stations), ULTRIX (DEC workstations), IRIX (SGI) and Linux (PC).

At a glance, the system has the following features.

Usual features: Explicit modeling primtives: arc, box, brick, cone, cylinder, dot, patch, polygon, plane, quadrics, sphere, torus, triangle. Height fields Linear transformations Object hierarchies Object instances Solid and flat textures Depth of field Penumbrae Transparent shadows Motion blur Interactive previewer	Less usual features: Implicit surfaces based upon points, lines, arcs, triangles, planes Selective visibility Clouds of light and halos Animation tools Time profiling tools Scalar, color and vector variables Image arithmetic Internal man pages Internal examples for most commands Thumbnail icons (really pretty) TIFF, TARGA, MTV, FLI formats