man/man1/pmapdump.1

.\" RCSid "$Id: pmapdump.1,v 1.6 2019/01/22 18:31:28 rschregle Exp $"
.TH PMAPDUMP 1 "$Date: 2019/01/22 18:31:28 $ $Revision: 1.6 $" RADIANCE

.SH NAME
pmapdump - generate RADIANCE scene description or point list representing
photon positions and (optionally) flux

.SH SYNOPSIS
pmapdump [\fB-a\fR] [\fB-n\fR \fInum1\fR] [\fB-r\fR \fIradscale1\fR] 
[\fB-f\fR | \fB-c\fR \fIrcol1\fR \fIgcol1\fR \fIbcol1\fR] 
         \fIpmap1\fR 
         [\fB-a\fR] [\fB-n\fR \fInum2\fR] [\fB-r\fR \fIradscale2\fR] 
[\fB-f\fR | \fB-c\fR \fIrcol2\fR \fIgcol2\fR \fIbcol2\fR] 
         \fIpmap2\fR ...

.SH DESCRIPTION
\fIpmapdump\fR takes one or more photon map files generated with
\fImkpmap(1)\fR as input and, by default, sends a RADIANCE scene description
of their photon distributions to the standard output. Photons are 
represented as spheres of material type \fIglow\fR. These can be 
visualised with e.g. \fIobjview(1)\fR, \fIrpict(1)\fR, or \fIrvu(1)\fR to 
assess the location and local density of photons in relation to the scene 
geometry. No additional light sources are necessary, as the spheres 
representing the photons are self-luminous.
.PP
Alternatively, photons can also be output as an ASCII point list, where
each line contains a photon's position and colour.
This point list can be imported in a 3D point cloud processor/viewer 
to interactively explore the photon map.
.PP
An arbitrary number of photon maps can be specified on the command line and
the respective photon type is determined automagically. Per default, the
different photon types are visualised as colour coded spheres/points 
according to the following default schema:
.IP
\fIBlue\fR: global photons 
.br
\fICyan\fR: precomputed global photons
.br
\fIRed\fR: caustic photons
.br
\fIGreen\fR: volume photons
.br
\fIMagenta\fR: direct photons
.br
\fIYellow\fR: contribution photons
.PP
These colours can be overridden for individual photon maps with the \fB-c\fR
option (see below). Alternatively, photons can be individually coloured
according to their actual RGB flux with the \fB-f\fR option (see below);
while this makes it difficult to discern photon types, it can be used to
quantitatively analyse colour bleeding effects, for example.

.SH OPTIONS
Options are effective for the photon map file immediately following on the
command line, and are reset to their defaults after completion of each dump. 
As such they must be set individually for each photon map.

.IP "\fB-a\fR"
Boolean switch to output photons as a point list in ASCII (text) format
instead of a RADIANCE scene.
Each output line consists of 6 tab-separated floating point values: the
X, Y, Z coordinates of the photon's position, and the R, G, B colour 
channels of its flux. These values. notably the flux, are expressed in
scientific notation if necessary to accommodate their high dynamic range. 

.IP
As \fIpmapdump\fR groups its options per photon map, this option must be
specified per photon map for consistent output. This prevents erroneously
dumping RADIANCE scene descriptions along with point lists, which will
fail to load in the 3D point cloud viewer.

.IP "\fB-c\fR \fIrcol\fR \fIgcol\fR \fIbcol\fR"
Specifies a custom sphere/point colour for the next photon map. The colour
is specified as an RGB triplet, with each component in the range (0..1].
Without this option, the default colour for the corresponding photon type 
is used. This option is mutually exclusive with \fB-f\fR.

.IP "\fB-f\fR"
Boolean switch to colour each sphere/point according to the corresponding 
photon's RGB flux instead of a constant colour. Note that no exposure is 
applied, and as such the resulting colours can span several orders of 
magnitude and may require tone mapping with \fIpcond(1)\fR for 
visualisation. This option is mutually exclusive with \fB-c\fR.

.IP "\fB-n \fInum\fR"
Specifies the number of spheres or points to dump for the next photon map.  
The dump is performed by random sampling with \fInum\fR as target count, 
hence the number actually output will be approximate. \fINum\fR may be
suffixed by a case-insensitive multiplier for convenience, where
\fIk\fR = 10^3 and \fIm\fR = 10^6, although the latter may lead to problems
when processing the output geometry with \fIoconv(1)\fR. The default number
is 10k.

.IP "\fB-r \fIradscale\fR"
Specifies a relative scale factor \fIradscale\fR for the sphere radius. The
sphere radius is determined automatically from an estimated average distance
between spheres so as to reduce clustering, assuming a uniform distribution. 
In cases where the distribution is substantially nonuniform (e.g. highly
localised caustics) the radius can be manually corrected with this option. 
The default value is 1.0. This option is ignored for point list output 
in conjuction with \fB-a\fR.

.SH NOTES
The RADIANCE scene output may contain many overlapping spheres in areas with
high photon density, particularly in caustics. This results in inefficient 
and slow octree generation with \fIoconv(1)\fR. Generally this can be 
improved by reducing \fInum\fR and/or \fIradscale\fR.

.SH EXAMPLES
Visualise the distribution of global and caustic photons superimposed
on the scene geometry with 5000 pale red and 10000 pale blue spheres, 
respectively:
.IP
pmapdump -n 5k -c 1 0.4 0.4 global.pm -n 10k -c 0.4 0.4 1 caustic.pm | 
oconv - scene.rad > scene_pm.oct
.PP
Visualise the caustic photon distribution superimposed on the scene geometry
with 10000 spheres coloured according to the photons' respective RGB flux:
.IP
pmapdump -n 10k -f caustic.pm | oconv - scene.rad > scene_pm.oct
.PP
But Capt. B wants 'em bigger:
.IP
pmapdump -r 4.0 bonzo.pm > bonzo_bigballz.rad
.PP
RADIANCE scene dumps may also be viewed on their own by simply piping the
output of \fIpmapdump\fR directly into \fIobjview(1)\fR (using the default
number of spheres in this example):
.IP
pmapdump zombo.pm | objview
.PP
Instead of a RADIANCE scene, dump photons as a (really long) point list to
an ASCII file for import into a 3D point cloud viewer:
.IP
pmapdump -a -f -n 1m lotsa.pm > lotsa_pointz.txt

.SH AUTHOR
Roland Schregle (roland.schregle@{hslu.ch,gmail.com})

.SH COPYRIGHT
(c) Fraunhofer Institute for Solar Energy Systems, Lucerne University of 
Applied Sciences and Arts.

.SH ACKNOWLEDGEMENT
Development of the RADIANCE photon mapping extension was sponsored by the 
German Research Foundation (DFG) and the Swiss National Science Foundation 
(SNF). Greetz to Capt. B!

.SH "SEE ALSO"
mkpmap(1), objview(1), oconv(1), rpict(1), rvu(1), 
\fIThe RADIANCE Photon Map Manual\fR,
\fIBonzo Daylighting Tool [TM]\fR


Revision:	1.7
Committed:	Tue Jan 22 19:50:09 2019 UTC (6 years, 3 months ago) by rschregle
Branch:	MAIN
Changes since 1.6:	+25 -19 lines
Log Message:	Minor revisions & clarifications
#	User	Rev	Content
1	rschregle	1.7	.\" RCSid "$Id: pmapdump.1,v 1.6 2019/01/22 18:31:28 rschregle Exp $"
2			.TH PMAPDUMP 1 "$Date: 2019/01/22 18:31:28 $ $Revision: 1.6 $" RADIANCE
3	greg	1.1
4			.SH NAME
5	rschregle	1.5	pmapdump - generate RADIANCE scene description or point list representing
6			photon positions and (optionally) flux
7	greg	1.1
8			.SH SYNOPSIS
9	rschregle	1.5	pmapdump [\fB-a\fR] [\fB-n\fR \fInum1\fR] [\fB-r\fR \fIradscale1\fR]
10			[\fB-f\fR \| \fB-c\fR \fIrcol1\fR \fIgcol1\fR \fIbcol1\fR]
11			\fIpmap1\fR
12			[\fB-a\fR] [\fB-n\fR \fInum2\fR] [\fB-r\fR \fIradscale2\fR]
13			[\fB-f\fR \| \fB-c\fR \fIrcol2\fR \fIgcol2\fR \fIbcol2\fR]
14			\fIpmap2\fR ...
15	greg	1.1
16			.SH DESCRIPTION
17			\fIpmapdump\fR takes one or more photon map files generated with
18	rschregle	1.5	\fImkpmap(1)\fR as input and, by default, sends a RADIANCE scene description
19			of their photon distributions to the standard output. Photons are
20			represented as spheres of material type \fIglow\fR. These can be
21			visualised with e.g. \fIobjview(1)\fR, \fIrpict(1)\fR, or \fIrvu(1)\fR to
22			assess the location and local density of photons in relation to the scene
23			geometry. No additional light sources are necessary, as the spheres
24			representing the photons are self-luminous.
25			.PP
26			Alternatively, photons can also be output as an ASCII point list, where
27			each line contains a photon's position and colour.
28			This point list can be imported in a 3D point cloud processor/viewer
29			to interactively explore the photon map.
30	greg	1.1	.PP
31			An arbitrary number of photon maps can be specified on the command line and
32	rschregle	1.7	the respective photon type is determined automagically. Per default, the
33	rschregle	1.5	different photon types are visualised as colour coded spheres/points
34			according to the following default schema:
35	greg	1.1	.IP
36			\fIBlue\fR: global photons
37			.br
38			\fICyan\fR: precomputed global photons
39			.br
40			\fIRed\fR: caustic photons
41			.br
42			\fIGreen\fR: volume photons
43			.br
44			\fIMagenta\fR: direct photons
45			.br
46			\fIYellow\fR: contribution photons
47	rschregle	1.2	.PP
48			These colours can be overridden for individual photon maps with the \fB-c\fR
49	rschregle	1.5	option (see below). Alternatively, photons can be individually coloured
50	rschregle	1.4	according to their actual RGB flux with the \fB-f\fR option (see below);
51			while this makes it difficult to discern photon types, it can be used to
52	rschregle	1.5	quantitatively analyse colour bleeding effects, for example.
53	greg	1.1
54			.SH OPTIONS
55			Options are effective for the photon map file immediately following on the
56			command line, and are reset to their defaults after completion of each dump.
57	rschregle	1.7	As such they must be set individually for each photon map.
58	greg	1.1
59	rschregle	1.5	.IP "\fB-a\fR"
60			Boolean switch to output photons as a point list in ASCII (text) format
61			instead of a RADIANCE scene.
62			Each output line consists of 6 tab-separated floating point values: the
63			X, Y, Z coordinates of the photon's position, and the R, G, B colour
64	rschregle	1.7	channels of its flux. These values. notably the flux, are expressed in
65			scientific notation if necessary to accommodate their high dynamic range.
66
67			.IP
68			As \fIpmapdump\fR groups its options per photon map, this option must be
69			specified per photon map for consistent output. This prevents erroneously
70			dumping RADIANCE scene descriptions along with point lists, which will
71			fail to load in the 3D point cloud viewer.
72
73			.IP "\fB-c\fR \fIrcol\fR \fIgcol\fR \fIbcol\fR"
74			Specifies a custom sphere/point colour for the next photon map. The colour
75			is specified as an RGB triplet, with each component in the range (0..1].
76			Without this option, the default colour for the corresponding photon type
77			is used. This option is mutually exclusive with \fB-f\fR.
78	rschregle	1.5
79			.IP "\fB-f\fR"
80			Boolean switch to colour each sphere/point according to the corresponding
81			photon's RGB flux instead of a constant colour. Note that no exposure is
82			applied, and as such the resulting colours can span several orders of
83			magnitude and may require tone mapping with \fIpcond(1)\fR for
84			visualisation. This option is mutually exclusive with \fB-c\fR.
85
86			.IP "\fB-n \fInum\fR"
87			Specifies the number of spheres or points to dump for the next photon map.
88			The dump is performed by random sampling with \fInum\fR as target count,
89			hence the number actually output will be approximate. \fINum\fR may be
90			suffixed by a case-insensitive multiplier for convenience, where
91			\fIk\fR = 10^3 and \fIm\fR = 10^6, although the latter may lead to problems
92			when processing the output geometry with \fIoconv(1)\fR. The default number
93			is 10k.
94	greg	1.1
95			.IP "\fB-r \fIradscale\fR"
96			Specifies a relative scale factor \fIradscale\fR for the sphere radius. The
97			sphere radius is determined automatically from an estimated average distance
98			between spheres so as to reduce clustering, assuming a uniform distribution.
99	rschregle	1.5	In cases where the distribution is substantially nonuniform (e.g. highly
100	greg	1.1	localised caustics) the radius can be manually corrected with this option.
101	rschregle	1.5	The default value is 1.0. This option is ignored for point list output
102			in conjuction with \fB-a\fR.
103	rschregle	1.2
104	greg	1.1	.SH NOTES
105	rschregle	1.5	The RADIANCE scene output may contain many overlapping spheres in areas with
106			high photon density, particularly in caustics. This results in inefficient
107			and slow octree generation with \fIoconv(1)\fR. Generally this can be
108			improved by reducing \fInum\fR and/or \fIradscale\fR.
109	greg	1.1
110			.SH EXAMPLES
111	rschregle	1.4	Visualise the distribution of global and caustic photons superimposed
112	rschregle	1.2	on the scene geometry with 5000 pale red and 10000 pale blue spheres,
113			respectively:
114	greg	1.1	.IP
115	rschregle	1.2	pmapdump -n 5k -c 1 0.4 0.4 global.pm -n 10k -c 0.4 0.4 1 caustic.pm \|
116	rschregle	1.5	oconv - scene.rad > scene_pm.oct
117	greg	1.1	.PP
118	rschregle	1.4	Visualise the caustic photon distribution superimposed on the scene geometry
119			with 10000 spheres coloured according to the photons' respective RGB flux:
120			.IP
121	rschregle	1.5	pmapdump -n 10k -f caustic.pm \| oconv - scene.rad > scene_pm.oct
122	rschregle	1.4	.PP
123	rschregle	1.7	But Capt. B wants 'em bigger:
124			.IP
125			pmapdump -r 4.0 bonzo.pm > bonzo_bigballz.rad
126			.PP
127	rschregle	1.5	RADIANCE scene dumps may also be viewed on their own by simply piping the
128			output of \fIpmapdump\fR directly into \fIobjview(1)\fR (using the default
129			number of spheres in this example):
130	greg	1.1	.IP
131			pmapdump zombo.pm \| objview
132	rschregle	1.5	.PP
133	rschregle	1.7	Instead of a RADIANCE scene, dump photons as a (really long) point list to
134			an ASCII file for import into a 3D point cloud viewer:
135	rschregle	1.5	.IP
136	rschregle	1.7	pmapdump -a -f -n 1m lotsa.pm > lotsa_pointz.txt
137	greg	1.1
138			.SH AUTHOR
139			Roland Schregle (roland.schregle@{hslu.ch,gmail.com})
140
141			.SH COPYRIGHT
142			(c) Fraunhofer Institute for Solar Energy Systems, Lucerne University of
143			Applied Sciences and Arts.
144
145			.SH ACKNOWLEDGEMENT
146			Development of the RADIANCE photon mapping extension was sponsored by the
147			German Research Foundation (DFG) and the Swiss National Science Foundation
148	rschregle	1.6	(SNF). Greetz to Capt. B!
149	greg	1.1
150			.SH "SEE ALSO"
151			mkpmap(1), objview(1), oconv(1), rpict(1), rvu(1),
152	rschregle	1.5	\fIThe RADIANCE Photon Map Manual\fR,
153			\fIBonzo Daylighting Tool [TM]\fR
154
155	greg	1.1