--- ray/doc/man/man1/mkillum.1	2004/09/17 21:43:49	1.4
+++ ray/doc/man/man1/mkillum.1	2007/12/13 07:03:36	1.7
@@ -1,4 +1,4 @@
-.\" RCSid "$Id: mkillum.1,v 1.4 2004/09/17 21:43:49 greg Exp $"
+.\" RCSid "$Id: mkillum.1,v 1.7 2007/12/13 07:03:36 greg Exp $"
 .TH MKILLUM 1 10/6/95 RADIANCE
 .SH NAME
 mkillum - compute illum sources for a RADIANCE scene
@@ -139,7 +139,8 @@ Only produce secondary sources for surfaces modified b
 .TP
 .BR n
 Do not produce any secondary sources.
-All input will be passed to the output unaffected.
+All input will be passed to the output unaffected, except any
+void surfaces will be removed.
 .TP
 .BI b =real
 Do not produce a secondary source for a surface if its average
@@ -173,6 +174,25 @@ If
 is zero, then a diffuse source is assumed and no distribution is
 created.
 .TP
+.BI d =string
+Set the surface Bidirectional Scattering Distribution Function (BSDF)
+to the given file.
+The RADIANCE library path will be searched if the file does not begin
+with a '.' or '~' character.
+This file must contain an LBNL Window 6 XML specification of a valid
+BSDF for the given surface, and all rays will be interpreted through
+this function.
+The orientation of the BSDF may be controlled with the
+.I u
+setting, described below.
+The thickness of the surface may be controlled with the
+.I t
+setting.
+If this variable has no setting or an integer is specified,
+.I mkillum
+returns to the default behavior of computing the output distribution
+directly.
+.TP
 .BI s =integer
 Set the number of ray samples per direction to
 .I integer.
@@ -193,6 +213,35 @@ will use the material type "illum" with the input surf
 as its alternate material.
 The default is
 .I l-.
+.TP
+.BI u =[+|-]{X|Y|Z}
+The given axis will be considered "up" for the purposes of interpreting
+BSDF data specified with the
+.I d
+variable.
+The BSDF will be reoriented relative to the surface as necessary to keep
+the up vector in the vertical plane that contains this axis and the
+surface normal.
+The default value is +Z.
+.TP
+.BI t =real
+Set the surface thickness to
+.I real
+in world coordinates.
+This value is used for determining where to start rays that need to begin
+on the opposite side of the surface, specifically to compute the incoming
+distribution for a BSDF computation.
+The default value is 0.
+.SH EXAMPLES
+The following command generates illum's corresponding to geometry
+in the files "it1.rad" and "it2.rad":
+.IP "" .3i
+mkillum \-ab 2 \-ad 1024 \-av .1 .1 .1 basic.oct "<" it1.rad it2.rad > illums.rad
+.PP
+The output file "illums.rad" would then be combined with the original
+scene geometry to create a more easily rendered composite.
+.SH ENVIRONMENT
+RAYPATH		the directories to check for auxiliary files.
 .SH AUTHOR
 Greg Ward
 .SH ACKNOWLEDGEMENT