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root/radiance/ray/doc/man/man1/dctimestep.1
Revision: 1.5
Committed: Fri Jan 11 17:21:39 2013 UTC (12 years, 3 months ago) by greg
Branch: MAIN
Changes since 1.4: +14 -2 lines
Log Message:
Fixed bug in dctimestep argument logic and added -if/-id options

File Contents

# Content
1 .\" RCSid $Id: dctimestep.1,v 1.4 2013/01/11 05:07:47 greg Exp $"
2 .TH DCTIMESTEP 1 12/09/09 RADIANCE
3 .SH NAME
4 dctimestep - compute annual simulation time-step(s) via matrix multiplication
5 .SH SYNOPSIS
6 .B dctimestep
7 [
8 .B "\-n nsteps"
9 ][
10 .B "\-o ospec"
11 ][
12 .B "\-i{f|d}
13 ]
14 .B DCspec
15 [
16 .B skyf
17 ]
18 .br
19 .B dctimestep
20 [
21 .B "\-n nsteps"
22 ][
23 .B "\-o ospec"
24 ][
25 .B "\-i{f|d}
26 ]
27 .B Vspec
28 .B Tbsdf.xml
29 .B Dmat.dat
30 [
31 .B skyf
32 ]
33 .SH DESCRIPTION
34 .I Dctimestep
35 has two invocation forms.
36 In the first form,
37 .I dctimestep
38 is given a daylight coefficient specification and an optional sky
39 vector or matrix, which may be read from the standard input if unspecified.
40 The daylight coefficients are multiplied against these sky values
41 and the results are written to the standard output.
42 This may be a list of color values or a combined Radiance image,
43 as explained below.
44 .PP
45 In the second form,
46 .I dctimestep
47 takes four input files, forming a matrix expression.
48 The first argument is the View matrix file that specifies how window output
49 directions are related to some set of measured values, such as an array of
50 illuminance points or images.
51 This matrix is usually computed by
52 .I rcontrib(1)
53 for a particular set of windows or skylight openings.
54 The second argument is the window transmission matrix, or BSDF, given as
55 a standard XML description.
56 The third argument is the Daylight matrix file that defines how sky patches
57 relate to input directions on the same opening.
58 This is usually computed using
59 .I genklemsamp(1)
60 with
61 .I rcontrib
62 in a separate run for each window or skylight orientation.
63 The final input is the sky contribution vector or matrix,
64 usually computed by
65 .I genskyvec(1),
66 which may be passed on the standard input.
67 This data is expected to be in ASCII format, whereas the
68 View and Daylight matrices
69 are more efficiently represented as binary float data if machine
70 byte-order is not an issue.
71 The
72 .I \-if
73 or
74 .I \-id
75 option may be used to specify that sky data is in float or double
76 format, instead.
77 (Note that binary double data may not be read from stdin.)\0
78 .PP
79 Sent to the standard output of
80 .I dctimestep
81 is either an ASCII color vector with as many RGB triplets
82 as there are rows in the View matrix, or a combined
83 .I Radiance
84 picture.
85 Which output is produced depends on the first argument.
86 A regular file name will be loaded and interpreted as a matrix to
87 generate a color results vector.
88 A file specification containing a '%d' format string will be
89 interpreted as a list of
90 .I Radiance
91 component pictures, which will be summed according to the computed
92 vector.
93 .PP
94 The
95 .I \-n
96 option may be used to compute multiple time steps in a
97 single invocation.
98 The sky input file must contain the number of
99 columns specified in each sky patch row, whether it is read
100 from the standard input or from an ASCII file.
101 The columns do not need to be given on the same
102 line, so long as the number of values totals 3*Nsteps*Npatches.
103 Input starts from the first patch at the first time step, then the
104 first patch at the second time step, and so on.
105 .PP
106 The
107 .I \-o
108 option may be used to specify a file or a set of output files
109 to use rather than the standard output.
110 If the given specification contains a '%d' format string, this
111 will be replaced by the time step index, starting from 1.
112 In this way, multiple output pictures may be produced,
113 or separate results vector (one per time step).
114 .SH EXAMPLES
115 To compute workplane illuminances at 3:30pm on Feb 10th:
116 .IP "" .2i
117 gensky 2 10 15:30 | genskyvec | dctimestep workplaneDC.dmx > Ill_02-10-1530.dat
118 .PP
119 To compute an image at 10am on the equinox from a set of component images:
120 .IP "" .2i
121 gensky 3 21 10 | genskyvec | dctimestep viewc%03d.hdr > view_03-21-10.hdr
122 .PP
123 To compute a set of illuminance contributions for Window 1 on
124 the Winter solstice at 2pm:
125 .IP "" .2i
126 gensky 12 21 14 | genskyvec | dctimestep IllPts.vmx Blinds20.xml Window1.dmx > Ill_12-21-14.dat
127 .PP
128 To compute Window2's contribution to an interior view at 12 noon on the Summer solstice:
129 .IP "" .2i
130 gensky 6 21 12 | genskyvec | dctimestep view%03d.hdr Blinds30.xml Window2.dmx > view_6-21-12.hdr
131 .SH AUTHOR
132 Greg Ward
133 .SH "SEE ALSO"
134 genklemsamp(1), genskyvec(1), mkillum(1), rcontrib(1), rtrace(1), vwrays(1)