# Last edited on 2013-03-24 22:33:57 by stolfi

IRT - A ray tracer that can use either plain floating point,
interval arithmetic (IA) or affine arithmetic (AA).

The files are my own work and are hereby placed in the public domain.

Code is provided "as is" for contemplation purposes only. As of
2013-03-24 it compiled and ran on J.Stolfi's Linux environment, but
your mileage may vary. No guarantees are expressed, stated, affirmed,
supported, honored, implied, or even vaguely suggested in a sort of
hypothetically subliminal way. Any losses or damages that may result
from use of this software are yours to keep.

Documentation is almost non-existent and the code was never fully
debugged. The "tests" subdirectory has a Makefile that runs it on some
test scenes. 

The input scene is specified as a 3-argument formula that defines an
implicit surface. A ".parms" file specifies camera view, light and
other basic parameters. The formula is given in a separate file, in a
specific pseudo-machine code (".pcode"). The Lisp program
"expr-to-pcode.lsp" converts a formula written in a legible notation
(".expr") to that pseudocode format.

The tracer does not support reflections, transparency, or any other
fancy effects.  I mean, not *intentionally*.

J.Stolfi, 2013-03-24