--- ray/src/cv/mgflib/mgfdoc.tr	1995/08/24 12:28:13	1.5
+++ ray/src/cv/mgflib/mgfdoc.tr	1995/12/04 12:27:04	1.12
@@ -1266,7 +1266,8 @@ corresponds to the measurement at
 Values in between are separated by
 .I "(l_max-l_min)/(N-1)"
 nanometers.
-All values must be non-negative, and the spectrum outside of the
+All values should be non-negative unless defining a component for
+complementary color mixing, and the spectrum outside of the
 specified range is assumed to be zero.
 (The visible range is 380 to 780 nm.)\0
 The actual units and scale of the measurements do not matter,
@@ -2387,7 +2388,7 @@ ring - create a circular ring with inner and outer rad
 .SH
 SYNOPSIS
 .LP
-.B cyl
+.B ring
 .I "vc rmin rmax"
 .SH
 DESCRIPTION
@@ -2500,9 +2501,11 @@ SEE ALSO
 .NH
 MGF Translators
 .LP
-Initially, there are four translators for MGF data, but only
-one of these is distributed with the MGF parser itself,
-.I mgfilt.
+Initially, there are five translators for MGF data, but only
+two of these are distributed with the MGF parser itself,
+.I mgfilt
+and
+.I mgf2inv.
 Two of the other translators,
 .I mgf2rad
 and
@@ -2515,7 +2518,7 @@ package\(dg.
 nestor.epfl.ch, or by WWW from
 "http://radsite.lbl.gov/radiance/HOME.html"
 .FE
-A third translator,
+The fifth translator,
 .I mgf2meta,
 converts to a 2-dimensional line plot, and is also
 distributed with Radiance.
@@ -2532,6 +2535,10 @@ unwanted entities.
 In future releases of MGF, this utility will also be handy for
 taking new entities and producing older versions of MGF for
 translators that have not yet been updated properly.
+.LP
+Mgf2inv converts from MGF to Inventor or VRML format.
+Some information is lost, because these formats do not support
+physical light sources or materials.
 .ds LH Translators
 .ds RH MGFILT
 .bp
@@ -2566,6 +2573,10 @@ In the first form, a single integer is given for the
 of MGF that is to be produced.
 Since MGF is in its first major release, this is not yet a useful
 form, but it will be when the second major release comes out.
+This has the necessary side-effect of expanding all included files.
+(See the
+.UL i
+entity.)\0
 .LP
 In the second form,
 .I mgfilt
@@ -2590,7 +2601,55 @@ mgfilt f,v,p,xf input.mgf > flatpoly.mgf
 .SH
 SEE ALSO
 .LP
-mgf2rad, rad2mgf
+i, mgf2inv, mgf2rad, rad2mgf
+.ds RH MGF2INV
+.bp
+.SH
+NAME
+.LP
+mgf2inv - convert from MGF to Inventor or VRML format
+.SH
+SYNOPSIS
+.LP
+.B mgf2inv
+[
+.B "-1|-2|-vrml"
+]
+[
+.B input ..
+]
+.SH
+DESCRIPTION
+.LP
+.I Mgf2inv
+takes one or more MGF input files and converts it to
+Inventor or VRML format.
+If the
+.I \-1
+option is used, then Inventor 1.0 ASCII output is produced.
+If the
+.I \-2
+option is used, then Inventor 2.0 ASCII output is produced.
+(This is the default.)\0
+If the
+.I \-vrml
+option is used, then VRML 1.0 ASCII output is produced.
+.LP
+This converter does not work properly for light sources, since
+the output formats do not support IES-type luminaires with recorded
+distributions.
+Also, some material information may be lost because Inventor lacks
+a physically valid reflectance model.
+.SH
+EXAMPLES
+.LP
+To take an MGF file and convert it to VRML format:
+.IP
+mgf2inv -vrml myscene.mgf > myscene.iv
+.SH
+SEE ALSO
+.LP
+mgf2rad, mgfilt, rad2mgf
 .ds RH MGF2RAD
 .bp
 .SH
@@ -3272,8 +3331,10 @@ and return one of the non-zero values from "parser.h" 
 #define MG_EMEM		8		/* out of memory */
 #define MG_ESEEK		9		/* file seek error */
 #define MG_EBADMAT	10		/* bad material specification */
+#define MG_ELINE		11		/* input line too long */
+#define MG_ECNTXT		12		/* unmatched context close */
 
-#define MG_NERRS	11
+#define MG_NERRS	13
 .DE
 If it is inappropriate to send output to standard error, the calling
 program should use the routines listed under
@@ -3357,7 +3418,10 @@ The
 function reads the next input line from the current file,
 returning the number of characters in the line, or zero if the
 end of file is reached or there is a file error.
-The function skips over escaped newlines, and keeps track of the
+If the value returned equals MG_MAXLINE-1,
+then the input line was too long, and you
+should return an MG_ELINE error.
+The function keeps track of the
 line number in the current file context
 .I mg_file,
 which also contains the line that was read.