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Comparing ray/doc/man/man1/rtrace.1 (file contents):
Revision 1.7 by greg, Tue Apr 19 01:15:06 2005 UTC vs.
Revision 1.18 by greg, Sat Dec 12 19:00:59 2009 UTC

# Line 87 | Line 87 | d      direction (normalized)
87   .IP
88   v       value (radiance)
89   .IP
90 + V       contribution (radiance)
91 + .IP
92   w       weight
93   .IP
94 < W       contribution
94 > W       color coefficient
95   .IP
96   l       effective length of ray
97   .IP
# Line 109 | Line 111 | m      modifier name
111   .IP
112   M       material name
113   .IP
114 + ~       tilde (end of trace marker)
115 + .IP
116   If the letter 't' appears in
117   .I spec,
118   then the fields following will be printed for every ray traced,
# Line 116 | Line 120 | not just the final result.
120   If the capital letter 'T' is given instead of 't', then all rays will
121   be reported, including shadow testing rays to light sources.
122   Spawned rays are indented one tab for each level.
123 + The tilde marker ('~') is a handy way of differentiating the final ray
124 + value from daughter values in a traced ray tree, and usually appears
125 + right before the 't' or 'T' output flags.
126 + E.g.,
127 + .I \-ov~TmW
128 + will emit a tilde followed by a tab at the end of each trace,
129 + which can be easily distinguished even in binary output.
130   .IP
131   Note that there is no space between this option and its argument.
132   .TP
# Line 138 | Line 149 | must appear in a separate option.
149   Add
150   .I mod
151   to the trace include list,
152 < so that it will be considered during the indirect calculation.
152 > so that it will be reported by the trace option.
153   The program can use either an include list or an exclude
154   list, but not both.
155   .TP
# Line 169 | Line 180 | option (below) may be used to override this.
180   This option is especially useful in
181   conjunction with ximage(1) for computing illuminance at scene points.
182   .TP
183 + .BR \-u
184 + Boolean switch to control uncorrelated random sampling.
185 + When "off", a low-discrepancy sequence is used, which reduces
186 + variance but can result in a brushed appearance in specular highlights.
187 + When "on", pure Monte Carlo sampling is used in all calculations.
188 + .TP
189   .BR \-I
190   Boolean switch to compute irradiance rather than radiance,
191   with the input origin and direction interpreted instead
# Line 213 | Line 230 | format.
230   .I \-f
231   option, above.)
232   .TP
233 + .BI -n \ nproc
234 + Execute in parallel on
235 + .I nproc
236 + local processes.
237 + This option is incompatible with
238 + .I \-P
239 + and
240 + .I \-PP,
241 + and is not currently supported with the
242 + .I \-I
243 + option.
244 + Multiple processes also do not work properly with ray tree output
245 + using any of the
246 + .I \-o*t*
247 + options.
248 + There is no benefit from specifying more processes than there are
249 + cores available on the system or the
250 + .I \-x
251 + setting, which forces a wait at each flush.
252 + .TP
253   .BI -dj \ frac
254   Set the direct jittering to
255   .I frac.
# Line 509 | Line 546 | source within a given scattering volume.
546   .BI -lr \ N
547   Limit reflections to a maximum of
548   .I N.
549 + If
550 + .I N
551 + is zero or negative, then Russian roulette is used for ray
552 + termination, and the
553 + .I -lw
554 + setting (below) must be positive.
555 + If N is a negative integer, then this sets the upper limit
556 + of reflections past which Russian roulette will not be used.
557 + In scenes with dielectrics and total internal reflection,
558 + a setting of 0 (no limit) may cause a stack overflow.
559   .TP
560   .BI -lw \ frac
561   Limit the weight of each ray to a minimum of
562   .I frac.
563 < During ray-tracing, a record is kept of the final contribution
564 < a ray would have to the image.
565 < If it is less then the specified minimum, the ray is not traced.
563 > During ray-tracing, a record is kept of the estimated contribution
564 > (weight) a ray would have in the image.
565 > If this weight is less than the specified minimum and the
566 > .I -lr
567 > setting (above) is positive, the ray is not traced.
568 > Otherwise, Russian roulette is used to
569 > continue rays with a probability equal to the ray weight
570 > divided by the given
571 > .I frac.
572   .TP
573   .BR -ld
574   Boolean switch to limit ray distance.
# Line 579 | Line 632 | system call will share memory on a copy-on-write basis
632   .SH EXAMPLES
633   To compute radiance values for the rays listed in samples.inp:
634   .IP "" .2i
635 < rtrace -ov scene.oct < samples.inp > radiance.out
635 > rtrace \-ov scene.oct < samples.inp > radiance.out
636   .PP
637   To compute illuminance values at locations selected with the 't'
638   command of
639   .I ximage(1):
640   .IP "" .2i
641 < ximage scene.pic | rtrace -h -x 1 -i scene.oct | rcalc -e '$1=47.4*$1+120*$2+11.6*$3'
641 > ximage scene.hdr | rtrace \-h \-x 1 \-i scene.oct | rcalc \-e '$1=47.4*$1+120*$2+11.6*$3'
642   .PP
643   To record the object identifier corresponding to each pixel in an image:
644   .IP "" .2i
645 < vwrays -fd scene.pic | rtrace -fda `vwrays -d scene.pic` -os scene.oct
645 > vwrays \-fd scene.hdr | rtrace \-fda `vwrays \-d scene.hdr` \-os scene.oct
646   .PP
647   To compute an image with an unusual view mapping:
648   .IP "" .2i
649 < cnt 640 480 | rcalc -e 'xr:640;yr:480' -f unusual_view.cal | rtrace
650 < -x 640 -y 480 -fac scene.oct > unusual.pic
649 > cnt 480 640 | rcalc \-e 'xr:640;yr:480' \-f unusual_view.cal | rtrace
650 > \-x 640 \-y 480 \-fac scene.oct > unusual.hdr
651   .SH ENVIRONMENT
652   RAYPATH         the directories to check for auxiliary files.
653   .SH FILES
# Line 613 | Line 666 | option.
666   Greg Ward
667   .SH "SEE ALSO"
668   getinfo(1), lookamb(1), oconv(1), pfilt(1), pinterp(1),
669 < pvalue(1), rpict(1), rvu(1), vwrays(1), ximage(1)
669 > pvalue(1), rpict(1), rtcontrib(1), rvu(1), vwrays(1), ximage(1)

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