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Revision: 1.5
Committed: Tue Mar 11 02:21:45 2008 UTC (16 years, 2 months ago) by greg
Branch: MAIN
CVS Tags: rad3R9
Changes since 1.4: +11 -3 lines
Log Message:
Added planisphere view type (-vts option) as requested by Axel Jacobs

File Contents

# User Rev Content
1 greg 1.5 .\" RCSid "$Id: rhpict.1,v 1.4 2007/09/04 17:36:41 greg Exp $"
2 greg 1.1 .TH RHPICT 1 3/10/99 RADIANCE
3     .SH NAME
4     rhpict - render a RADIANCE picture from a holodeck file
5     .SH SYNOPSIS
6     .B rhpict
7     [
8     .B options
9     ]
10     .B holodeck
11     .SH DESCRIPTION
12     .I Rhpict
13     generates one or more pictures from the RADIANCE holodeck file
14     .I holodeck
15     and sends them to the standard output.
16     The
17     .I \-o
18     option may be used to specify an alternate output file.
19     Other options specify the viewing parameters and provide
20     some control over the calculation.
21     .PP
22     The view as well as some of the other controls
23     are shared in common with the
24     .I rpict(1)
25     command.
26     The options that are unique to
27     .I rhpict
28     are given first, followed by the more familiar ones.
29     .TP 10n
30     .BI -s
31     Use the smooth resampling algorithm, which amounts to linear interpolation
32     between ray samples with additional edge detection along color and object
33     boundaries.
34     This is the default.
35     .TP
36     .BI -r \ rf
37     Use random resampling, where
38     .I rf
39     is a fraction from 0 to 1 indicating the desired degree of randomness.
40     A random fraction of 0 is not the same as smooth resampling,
41     because there is no linear interpolation, just Voronoi regions.
42     Values greater than 1 produce interesting underwater effects.
43     .TP
44     .BI -x \ res
45     Set the maximum x resolution to
46     .I res.
47     .TP
48     .BI -y \ res
49     Set the maximum y resolution to
50     .I res.
51     .TP
52     .BI -pa \ rat
53     Set the pixel aspect ratio (height over width) to
54     .I rat.
55     Either the x or the y resolution will be reduced so that the pixels have
56     this ratio for the specified view.
57     If
58     .I rat
59     is zero, then the x and y resolutions will adhere to the given maxima.
60     .TP
61     .BI -pe \ expval
62     Set the exposure value for the output pictures to
63     .I expval.
64     Since filtering is performed by
65     .I rhpict,
66     there is little sense in passing the output through
67     .I pfilt(1),
68     other than changing the exposure.
69     This option eliminates that need.
70     The value may be specified either as a multiplier, or as a number
71     f-stops preceeded by a '+' or '-' character.
72     .TP
73     .BI -vt t
74     Set view type to
75     .I t.
76     If
77     .I t
78     is 'v', a perspective view is selected.
79     If
80     .I t
81     is 'l', a parallel view is used.
82     A cylindrical panorma may be selected by setting
83     .I t
84     to the letter 'c'.
85     This view is like a standard perspective vertically, but projected
86     on a cylinder horizontally (like a soupcan's-eye view).
87 greg 1.5 Three fisheye views are provided as well; 'h' yields a hemispherical fisheye
88     view, 'a' results in angular fisheye distortion, and 's'
89     results in a planisphere (stereographic) projection.
90 greg 1.1 A hemispherical fisheye is a projection of the hemisphere onto a circle.
91     The maximum view angle for this type is 180 degrees.
92     An angular fisheye view is defined such that distance from the center of
93     the image is proportional to the angle from the central view direction.
94     An angular fisheye can display a full 360 degrees.
95 greg 1.5 A planisphere fisheye view maintains angular relationships between lines,
96     and is commonly used for sun path analysis.
97     This is more commonly known as a
98     "stereographic projection," but we avoid the term here so as not to
99     confuse it with a stereoscopic pair.
100     A planisphere fisheye can display up to (but not including) 360 degrees,
101     although distortion becomes extreme as this limit is approached.
102 greg 1.1 Note that there is no space between the view type
103     option and its single letter argument.
104     .TP
105     .BI -vp " x y z"
106     Set the view point to
107     .I "x y z".
108     This is the focal point of a perspective view or the
109     center of a parallel projection.
110     .TP
111     .BI -vd " xd yd zd"
112     Set the view direction vector to
113     .I "xd yd zd".
114     .TP
115     .BI -vu " xd yd zd"
116     Set the view up vector (vertical direction) to
117     .I "xd yd zd".
118     .TP
119     .BI -vh \ val
120     Set the view horizontal size to
121     .I val.
122     For a perspective projection (including fisheye views),
123     .I val
124     is the horizontal field of view (in degrees).
125     For a parallel projection,
126     .I val
127     is the view width in world coordinates.
128     .TP
129     .BI -vv \ val
130     Set the view vertical size to
131     .I val.
132     .TP
133     .BI -vo \ val
134     Set the view fore clipping plane at a distance of
135     .I val
136     from the view point.
137     The plane will be perpendicular to the view direction for
138     perspective and parallel view types.
139     For fisheye view types, the clipping plane is actually a clipping
140     sphere, centered on the view point with radius
141     .I val.
142     Objects in front of this imaginary surface will not be visible.
143     This may be useful for seeing through walls (to get a longer
144     perspective from an exterior view point) or for incremental
145     rendering.
146     A value of zero implies no foreground clipping.
147     A negative value produces some interesting effects, since it creates an
148     inverted image for objects behind the viewpoint.
149     This possibility is provided mostly for the purpose of rendering
150     stereographic holograms.
151     .TP
152     .BI -va \ val
153     Set the view aft clipping plane at a distance of
154     .I val
155     from the view point.
156     Like the view fore plane, it will be perpendicular to the view
157     direction for perspective and parallel view types.
158     For fisheye view types, the clipping plane is actually a clipping
159     sphere, centered on the view point with radius
160     .I val.
161     Objects behind this imaginary surface will not be visible.
162     A value of zero means no aft clipping, and is the only way to see
163     infinitely distant objects such as the sky.
164     .TP
165     .BI -vs \ val
166     Set the view shift to
167     .I val.
168     This is the amount the actual image will be shifted to the right of
169     the specified view.
170     This is option is useful for generating skewed perspectives or
171     rendering an image a piece at a time.
172     A value of 1 means that the rendered image starts just to the right of
173     the normal view.
174 greg 1.4 A value of \-1 would be to the left.
175 greg 1.1 Larger or fractional values are permitted as well.
176     .TP
177     .BI -vl \ val
178     Set the view lift to
179     .I val.
180     This is the amount the actual image will be lifted up from the
181     specified view, similar to the
182     .I \-vs
183     option.
184     .TP
185     .BI -vf \ file
186     Get view parameters from
187     .I file,
188 greg 1.3 which may be a picture or a file created by rvu (with the "view" command).
189 greg 1.1 .TP
190     .BI -S \ seqstart
191     Instead of generating a single picture based only on the view
192     parameters given on the command line, this option causes
193     .I rhpict
194     to read view options from the standard input and for each line
195     containing a valid view specification, generate a corresponding
196     picture.
197     .I Seqstart
198     is a positive integer that will be associated with the first output
199     frame, and incremented for successive output frames.
200     By default, each frame is concatenated to the output stream, but it
201     is possible to change this action using the
202     .I \-o
203     option (described below).
204     Multiple frames may be later extracted from a single output stream using the
205     .I ra_rgbe(1)
206     command.
207     .TP
208     .BI -o \ fspec
209     Send the picture(s) to the file(s) given by
210     .I fspec
211     instead of the standard output.
212     If this option is used in combination with
213     .I \-S
214     and
215     .I fspec
216     contains an integer field for
217     .I printf(3)
218     (eg., "%03d") then the actual output file name will include
219     the current frame number.
220     .TP
221     .BR \-w
222     Turn off warning messages.
223     .SH EXAMPLE
224 greg 1.4 rhpict \-vp 10 5 3 \-vd 1 \-.5 0 scene.hdk > scene.pic
225 greg 1.1 .PP
226 greg 1.4 rpict \-S 1 \-o frame%02d.pic scene.hdk < keyframes.vf
227 greg 1.1 .SH AUTHOR
228     Greg Ward
229     .SH "SEE ALSO"
230     getinfo(1), pfilt(1), pinterp(1),
231 greg 1.3 printf(3), ra_rgbe(1), rholo(1), rpict(1), rvu(1)