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Comparing ray/doc/man/man1/obj2mesh.1 (file contents):
Revision 1.1 by greg, Tue Mar 11 22:48:20 2003 UTC vs.
Revision 1.3 by greg, Fri Mar 14 21:27:45 2003 UTC

# Line 5 | Line 5 | obj2mesh - create a compiled RADIANCE mesh file from W
5   .SH SYNOPSIS
6   .B obj2mesh
7   [
8 + .B "\-a matinput"
9 + ][
10   .B "\-n objlim"
11   ][
12   .B "\-r maxres"
# Line 25 | Line 27 | reads a Wavefront .OBJ file from
27   which is sent to
28   .I output.rtm
29   (or standard output).
30 + Any RADIANCE material descriptions included via one or more
31 + .I \-a
32 + options will be compiled and stored in the mesh as well.
33   This mesh may be included in a RADIANCE scene description via the
34   .I mesh
35   primitive, thus:
# Line 37 | Line 42 | mod mesh id
42   .br
43   0
44   .PP
45 < The syntax and semantics are nearly identical to the RADIANCE
45 > The syntax and semantics are identical to the RADIANCE
46   .I instance
47 < primitive, except that the mesh modifier may not be "void", since
48 < materials are not included in a compiled mesh file.
47 > primitive.
48 > If
49 > .I mod
50 > is "void", then the stored mesh materials will be applied during rendering.
51 > Otherwise, the given material will be substituted on
52 > all the mesh surfaces.
53   .PP
54   The
55   .I \-n
# Line 51 | Line 60 | less memory, but potentially slower rendering.
60   Smaller values may produce faster renderings,
61   since the default number (15) is on the high side to reduce
62   the compiled mesh octree size.
63 < Values below 6 are not recommended, since the median
64 < valence (number of adjacent faces) for a mesh vertex is 6,
65 < and smaller limits will result in pointless octree subdivision.
63 > Values below 6 are not recommended, since this is the median
64 > valence for a mesh vertex (the number of adjacent faces),
65 > and smaller values will result in pointless octree subdivision.
66   .PP
67   The
68   .I \-r
# Line 70 | Line 79 | Although the mesh file format is binary, it is meant t
79   between machines.
80   The only limitation is that machines with radically different integer
81   sizes will not work together.
82 + .SH DETAILS
83 + The following Wavefront statements are understood and compiled by
84 + .I obj2mesh.
85 + .TP 10n
86 + .BI v " x y z"
87 + A vertex location, given by its Cartesian coordinates.
88 + The final mesh position may of course be modified by
89 + the transform arguments given to the
90 + .I mesh
91 + primitive in the Radiance scene description.
92 + .TP
93 + .BI vn " dx dy dz"
94 + A vertex normal vector, given by its three
95 + direction components, which will be normalized by
96 + .I obj2mesh.
97 + Normals will be interpolated over the mesh
98 + during rendering to produce a smooth surface.
99 + If no vertex normals are present, the mess will appear tesselated.
100 + A zero length normal (i.e., 0 0 0) will generate a syntax error.
101 + .TP
102 + .BI vt " u v"
103 + A local vertex texture coordinate.
104 + These coordinates will be interpolated and passed
105 + to the "Lu" and "Lv" variables during rendering.
106 + Local coordinates can extend over any desired range of values.
107 + .TP
108 + .BI usemtl " mname"
109 + A material name.
110 + The following faces will use the named material, which is
111 + taken from the material definitions in the
112 + .I \-a
113 + input file(s).
114 + .TP
115 + .BI g " gname"
116 + Group association.
117 + The following faces are associated with the named group.
118 + If no "usemtl" statement has been
119 + encountered, the current group is used for the surface material
120 + identifier.
121 + .TP
122 + .BI f " v1/t1/n1 v2/t2/n2 v3/t3/n3" " .."
123 + A polygonal face.
124 + Polygon vertices are specified as three indices separated
125 + by slashes ('/').
126 + The first index is the vertex location, the
127 + second index is the local (u,v) texture coordinate, and the
128 + third index is the vertex surface normal.
129 + Positive indices count from the beginning of the input,
130 + where the first vertex position (
131 + .I v
132 + statement) is numbered 1, and likewise
133 + for the first texture coordinate and the first surface normal.
134 + Negative indices count backward from the current position in
135 + the input, where -1 is the last vertex encountered, -2
136 + is the one before that, etc.
137 + An index of 0 may be used for the vertex texture or normal to
138 + indicate none, or these may be left off entirely.
139 + All faces will be broken into triangles in the final mesh.
140 + .I Obj2mesh
141 + currently makes an unsafe assumption that faces are convex,
142 + which may result in odd results if they are not.
143 + .PP
144 + All other statement types will be ignored on the input.
145 + Statements understood by
146 + .I obj2rad(1)
147 + will be ignored silently; other statements will generate
148 + a warning message after translation to indicate how much was missed.
149   .SH DIAGNOSTICS
150   There are four basic error types reported by obj2mesh:
151   .IP
# Line 88 | Line 164 | However, the following internal errors should be menti
164   .IP "Set overflow in addobject (id)"
165   This error occurs when too many surfaces are close together in a
166   scene.
167 < Sometimes a dense mesh can be accomodated by increasing
167 > Sometimes a dense mesh can be accommodated by increasing
168   the maximum resolution (by powers of two) using the
169   .I \-r
170   option, but usually this error indicates something is wrong.
# Line 107 | Line 183 | oconv mesh.obj mesh.rtm
183   .SH AUTHOR
184   Greg Ward
185   .SH "SEE ALSO"
186 < gensurf(1), getinfo(1), make(1),
186 > gensurf(1), getinfo(1), make(1), obj2rad(1),
187   oconv(1), rpict(1), rview(1), rtrace(1), xform(1)

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