--- ray/doc/man/man1/rcontrib.1	2018/01/26 18:31:23	1.15
+++ ray/doc/man/man1/rcontrib.1	2020/09/09 21:28:19	1.18
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: rcontrib.1,v 1.15 2018/01/26 18:31:23 rschregle Exp $"
+.\" RCSid "$Id: rcontrib.1,v 1.18 2020/09/09 21:28:19 greg Exp $"
 .TH RCONTRIB 1 5/25/05 RADIANCE
 .SH NAME
 rcontrib - compute contribution coefficients in a RADIANCE scene
@@ -9,6 +9,8 @@ rcontrib - compute contribution coefficients in a RADI
 ][
 .B \-V
 ][
+.B "\-t secs"
+][
 .B "\-c count"
 ][
 .B \-fo
@@ -119,6 +121,11 @@ Note that output flushing via zero-direction rays is d
 .I \-c
 set to zero.
 .PP
+If progress reports are desired, the
+.I \-t
+option specifies a time interval in seconds for reports sent to
+standard error.
+.PP
 The output of
 .I rcontrib
 has many potential uses.
@@ -211,7 +218,7 @@ Additional parameter values that apply only to this mo
 with a
 .I \-p
 option, which contains a list of variable names and assigned values, separated
-by commas or semicolons.
+by commas, colons, or semicolons.
 The computed bin value will be
 rounded to the nearest whole number.
 (Negative bin values will be silently ignored.)\0
@@ -330,6 +337,11 @@ rcontrib \-I+ \-h \-V \-fo \-o c_%s.dat \-M lights \-a
 scene.oct < test.dat,
 .SH ENVIRONMENT
 RAYPATH		path to search for \-f and \-M files
+.SH BUGS
+We do not currently compute contributions or coefficients properly
+in scenes with participating media.
+A single warning will be issued if a scattering or absorbing medium
+is detected.
 .SH AUTHOR
 Greg Ward
 .SH "SEE ALSO"