.\" RCSid "$Id: genrev.1,v 1.2 2003/12/09 15:59:06 greg Exp $"
.TH GENREV 1 11/15/93 RADIANCE
.SH NAME
genrev - generate a RADIANCE description of surface of revolution
.SH SYNOPSIS
.B "genrev mat name 'z(t)' 'r(t)' nseg"
[
.B "\-e expr"
][
.B "\-f file"
][
.B \-s
]
.SH DESCRIPTION
.I Genrev
produces a RADIANCE scene description of a
surface of revolution.
The object will be composed of
.I nseg
cones, cups, cylinders, tubes or rings
following the parametric curve defined by
.I z(t)
(height)
and
.I r(t)
(radius).
When
.I z
is increasing with t, the surface normal points outward.
When
.I z
is decreasing, the normal points inward.
The variable
.I t
used in the function expressions varies
from 0 to 1 in even steps of
.I 1/nseg.
The expressions are of the same type used in RADIANCE
function files.
Auxiliary expressions and/or files may be specified
in any number of
.I \-e
and
.I \-f
options.
The
.I \-s
option smooths the surfaces using Phong normal interpolation.
.SH EXAMPLE
To generate a torus with an inner radius of 1 and an outer radius
of 3:
.IP "" .2i
genrev steel torus 'sin(2*PI*t)' '1+cos(2*PI*t)' 32
.SH AUTHOR
Greg Ward
.SH BUGS
The -s option doesn't modify the surface normal correctly
for the opposite side.
.SH "SEE ALSO"
calc(1), genbox(1), gensurf(1), genworm(1), rpict(1), rview(1), xform(1)