--- ray/doc/ray.1	2003/03/15 17:32:55	1.4
+++ ray/doc/ray.1	2007/08/23 04:13:50	1.13
@@ -1,8 +1,8 @@
 .\" RCSid "$Id"
 .\" Print using the -ms macro package
-.DA 1/20/99
+.DA 10/17/2006
 .LP
-.tl """Copyright \(co 2003 Regents, University of California
+.tl """Copyright \(co 2006 Regents, University of California
 .sp 2
 .TL
 The
@@ -402,7 +402,7 @@ mod spotlight id
 .LP
 .UL Mirror
 .PP
-Mirror is used for planar surfaces that produce secondary
+Mirror is used for planar surfaces that produce virtual
 source reflections.
 This material should be used sparingly, as it may cause the light
 source calculation to blow up if it is applied to many small surfaces.
@@ -426,12 +426,12 @@ mod mirror id
 .UL Prism1
 .PP
 The prism1 material is for general light redirection from prismatic
-glazings, generating secondary light sources.
+glazings, generating virtual light sources.
 It can only be used to modify a planar surface (i.e., a polygon or disk)
 and should not result in either light concentration or scattering.
 The new direction of the ray can be on either side of the material,
 and the definitions must have the correct bidirectional properties
-to work properly with secondary light sources.
+to work properly with virtual light sources.
 The arguments give the coefficient for the redirected light
 and its direction.
 .DS
@@ -1109,10 +1109,6 @@ which serves as a form of opacity control when used wi
 Vname is the coefficient defined in funcfile that determines the influence
 of foreground.
 The background coefficient is always (1-vname).
-Since the references are not resolved until runtime, the last
-definitions of the modifier id's will be used.
-This can result in modifier loops, which are detected by the
-renderer.
 .LP
 .UL Mixdata
 .PP
@@ -1239,8 +1235,7 @@ If no file is needed by a given primitive because all 
 variables are global, a period (`.') can be given in
 place of the file name.
 It is also possible to give an expression instead of a straight
-variable name in a scene file, although such expressions should
-be kept simple if possible.
+variable name in a scene file.
 Also, functions (requiring parameters)
 must be given as names and not as expressions.
 .PP
@@ -1495,6 +1490,11 @@ the Ecole Polytechnique Federale de Lausanne (EPFL Uni
 in Lausanne, Switzerland.
 .NH 1
 References
+.LP
+Cater, K., A. Chalmers, G. Ward,
+``Detail to Attention: Exploiting Visual Tasks for Selective Rendering,''
+.I "Eurograhics Symposium on Rendering",
+June 2003.
 .LP
 Ward, G., Elena Eydelberg-Vileshin,
 ``Picture Perfect RGB Rendering Using Spectral Prefiltering and