--- ray/src/cv/mgflib/mgfdoc.tr	1995/08/28 16:45:59	1.6
+++ ray/src/cv/mgflib/mgfdoc.tr	1996/04/05 16:35:25	1.15
@@ -5,8 +5,9 @@
 .vs 12
 .nr PD .5v
 .ds LF MGF
-.ds RF Version 1.0
-.DA May 1995
+.ds RF Version 1.1
+.\" !Remember to update date on each modification!
+.DA February 1996
 .TL
 The Materials and Geometry Format
 .AU
@@ -42,7 +43,7 @@ and sample scenes and objects at the web site,
 "http://radsite.lbl.gov/mgf/HOME.html".
 .RE
 .LP
-The standard parser provides both immediate and a long-term
+The standard parser provides both immediate and long-term
 benefits, since it presents a programming interface that is more
 stable even than the language itself.
 Unlike AutoCAD DXF and other de facto standards, a change to the
@@ -282,7 +283,7 @@ ring, torus, prism
 T}
 Material	m	2-sided black	T{
 sides, rd, td,
-ed, rs, ts
+ed, rs, ts, ir
 T}	T{
 f, sph, cyl, cone,
 ring, torus, prism
@@ -1674,7 +1675,7 @@ EXAMPLE
 # A 100-watt incandescent bulb (1600 lumens) modeled as a sphere
 m
 	c
-	cct 3000
+		cct 3000
 	ed 87712
 v cent =
 	p 0 0 0
@@ -2388,7 +2389,7 @@ ring - create a circular ring with inner and outer rad
 .SH
 SYNOPSIS
 .LP
-.B cyl
+.B ring
 .I "vc rmin rmax"
 .SH
 DESCRIPTION
@@ -2501,9 +2502,12 @@ 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 six translators for MGF data, and
+three of these are distributed with the MGF parser itself,
+.I mgfilt,
+.I mgf2inv
+and
+.I 3ds2mgf.
 Two of the other translators,
 .I mgf2rad
 and
@@ -2516,7 +2520,7 @@ package\(dg.
 nestor.epfl.ch, or by WWW from
 "http://radsite.lbl.gov/radiance/HOME.html"
 .FE
-A third translator,
+The sixth translator,
 .I mgf2meta,
 converts to a 2-dimensional line plot, and is also
 distributed with Radiance.
@@ -2533,6 +2537,14 @@ 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.
+.LP
+3ds2mgf converts from 3D Studio binary format to MGF.
+Care must be taken to correct for errors in the material descriptions,
+since 3D Studio is completely non-physical.
 .ds LH Translators
 .ds RH MGFILT
 .bp
@@ -2567,6 +2579,10 @@ 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
@@ -2591,7 +2607,159 @@ 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(1), mgfilt(1), 3ds2mgf(1), rad2mgf(1)
+.ds RH 3DS2MGF
+.bp
+.SH
+NAME
+.LP
+3ds2mgf - convert 3D Studio binary file to Materials and Geometry Format
+.SH
+SYNOPSIS
+.LP
+.B 3ds2mgf
+.B input
+[
+.B output
+]
+[
+.B -lMatlib
+][
+.B -xObjname
+][
+.B -sAngle
+][
+.B -aAnimfile
+][
+.B -fN
+]
+.SH
+DESCRIPTION
+.LP
+.I 3ds2mgf
+converts a 3D Studio binary scene description
+to the Materials and Geometry Format (MGF).
+If no output file name is given, the input root name
+will be taken as the output root, and an "mgf" extension
+will be added.
+This file will contain any light sources and materials, and an include
+statement for a similarly named file ending in "inc", which will contain
+the MGF geometry of all the translated 3DS meshes.
+.LP
+The MGF material names and properties
+for the surfaces will be those assigned in 3D Studio,
+unless they are named in one or more MGF material libraries given in a
+.I -l
+option.
+.LP
+The
+.I -x
+option may be used to exclude a named object from the output.
+.LP
+The
+.I -s
+option may be used to adjust automatic mesh smoothing such that adjacent
+triangle faces with less than the given angle between them (in degrees)
+will be smoothed.
+A value of zero turns smoothing off.
+The default value is 60 degrees.
+.LP
+The
+.I -a
+option may be used to specify a 3D Studio animation file, and together with the
+.I -f
+option,
+.I 3ds2mgf
+will generate a scene description for the specified frame.
+.LP
+Note that there are no spaces between the options and their arguments.
+.SH
+LIMITATIONS
+.LP
+Obviously, since 3D Studio has no notion of physical materials, the
+translation to MGF material descriptions is very ad hoc, and it will
+usually be necessary to edit the materials and light sources in
+the output file or replace materials with proper entries from a material
+library using the
+.I -l
+option.
+.LP
+With smoothing turned on (i.e., a non-zero value for the
+.I -s
+option), vertices in the MGF output will not be linked in a proper
+mesh for each object.
+This is due to the way the automatic smoothing code was originally
+written, and is too difficult to repair.
+If a good mesh is needed, then smoothing must be turned off.
+.SH
+EXAMPLES
+.LP
+To convert a 3D Studio robot model to MGF without smoothing.
+(Output will be put into "robot.mgf" and "robot.inc".)
+.IP
+3ds2mgf robot.3ds -s0
+.LP
+To convert a DC10 jet model to MGF using a hand-created material library:
+.IP
+3ds2mgf dc10.3ds -ldc10mat.mgf
+.SH
+AUTHORS
+.LP
+Steve Anger, Jeff Bowermaster and Greg Ward
+.br
+Extended from 3ds2pov 1.8.
+.SH
+SEE ALSO
+.LP
+mgf2inv(1), mgf2meta(1), mgf2rad(1)
 .ds RH MGF2RAD
 .bp
 .SH
@@ -3266,15 +3434,17 @@ and return one of the non-zero values from "parser.h" 
 #define MG_EUNK		1		/* unknown entity */
 #define MG_EARGC		2		/* wrong number of arguments */
 #define MG_ETYPE		3		/* argument type error */
-#define MG_EILL				4		/* illegal argument value */
+#define MG_EILL			4		/* illegal argument value */
 #define MG_EUNDEF		5		/* undefined reference */
 #define MG_ENOFILE		6		/* cannot open input file */
 #define MG_EINCL		7		/* error in included file */
 #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
@@ -3358,7 +3528,10 @@ 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.
@@ -3694,7 +3867,7 @@ To link identical vertices, one must also check that t
 transform has not changed, which is uniquely identified by the
 global
 .I xf_context->xid
-variable, but only if one is using the parser libraries transform
+variable, but only if one is using the parser library's transform
 handler.
 (See the
 .I xf_handler
@@ -4425,7 +4598,7 @@ familiar Gaussian model of MGF.
 The hardest part is translating the specular power to a roughness value.
 For this, we recommend the following approximation:
 .IP
-roughness = 0.6/sqrt(specular_power)
+roughness = sqrt(2/specular_power)
 .LP
 It is not a perfect correlation, but it is about as close as one can get.
 .NH 3