--- ray/doc/man/man1/vwrays.1	2008/11/10 19:08:17	1.6
+++ ray/doc/man/man1/vwrays.1	2019/11/07 23:20:28	1.11
@@ -1,10 +1,10 @@
-.\" RCSid "$Id: vwrays.1,v 1.6 2008/11/10 19:08:17 greg Exp $"
+.\" RCSid "$Id: vwrays.1,v 1.11 2019/11/07 23:20:28 greg Exp $"
 .TH VWRAYS 1 1/15/99 RADIANCE
 .SH NAME
 vwrays - compute rays for a given picture or view
 .SH SYNOPSIS
 .B vwrays
-.B "[ -i -f{a|f|d} | -d ]"
+.B "[ -i -u -f{a|f|d} -c rept | -d ]"
 {
 .B "view opts .."
 |
@@ -25,6 +25,9 @@ The
 .I \-i
 option may be used to specify desired pixel positions on the standard
 input rather than generating all the pixels for a given view.
+If the
+.I \-u
+option is also given, output will be unbuffered.
 .PP
 The
 .I \-f
@@ -34,6 +37,18 @@ Using raw float or double records for example can redu
 requirements of transferring and interpreting information in
 .I rtrace.
 .PP
+The
+.I \-c
+option repeats each pixel the given number of times (default is 1).
+This is most useful when sending rays to
+.I rcontrib(1)
+with the same
+.I \-c
+setting, providing a much faster way to average pixels over image sets.
+The
+.I \-pj
+option should be used to jitter sample postions in most cases.
+.PP
 View options may be any combination of standard view parameters described
 in the
 .I rpict(1)
@@ -90,8 +105,8 @@ otherwise, which would produce a uniform clipping dist
 .PP
 If a picture is given on the command line rather than a set of view options,
 then the view and image dimensions are taken from the picture file, and
-the reported ray origins and directions will exactly match the center of each
-pixel in the picture.
+the reported ray origins and directions will match the center of each
+pixel in the picture (plus optional jitter).
 .PP
 If a depth buffer file is given as well, then
 .I vwrays
@@ -129,4 +144,4 @@ can reproduce any pixel ordering (i.e., any image orie
 a rendered picture, it will only produce standard scanline-ordered rays when 
 given a set of view parameters.
 .SH "SEE ALSO"
-rcalc(1), rpict(1), rtcontrib(1), rtrace(1)
+rcalc(1), rcode_depth(1), rcontrib(1), rpict(1), rtpict(1), rtrace(1)