| 1 | .\" RCSid "$Id: rhpict.1,v 1.2 2003/12/09 15:59:06 greg Exp $" | 
| 2 | .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 | Two fisheye views are provided as well; 'h' yields a hemispherical fisheye | 
| 88 | view and 'a' results in angular fisheye distortion. | 
| 89 | A hemispherical fisheye is a projection of the hemisphere onto a circle. | 
| 90 | The maximum view angle for this type is 180 degrees. | 
| 91 | An angular fisheye view is defined such that distance from the center of | 
| 92 | the image is proportional to the angle from the central view direction. | 
| 93 | An angular fisheye can display a full 360 degrees. | 
| 94 | Note that there is no space between the view type | 
| 95 | option and its single letter argument. | 
| 96 | .TP | 
| 97 | .BI -vp " x y z" | 
| 98 | Set the view point to | 
| 99 | .I "x y z". | 
| 100 | This is the focal point of a perspective view or the | 
| 101 | center of a parallel projection. | 
| 102 | .TP | 
| 103 | .BI -vd " xd yd zd" | 
| 104 | Set the view direction vector to | 
| 105 | .I "xd yd zd". | 
| 106 | .TP | 
| 107 | .BI -vu " xd yd zd" | 
| 108 | Set the view up vector (vertical direction) to | 
| 109 | .I "xd yd zd". | 
| 110 | .TP | 
| 111 | .BI -vh \ val | 
| 112 | Set the view horizontal size to | 
| 113 | .I val. | 
| 114 | For a perspective projection (including fisheye views), | 
| 115 | .I val | 
| 116 | is the horizontal field of view (in degrees). | 
| 117 | For a parallel projection, | 
| 118 | .I val | 
| 119 | is the view width in world coordinates. | 
| 120 | .TP | 
| 121 | .BI -vv \ val | 
| 122 | Set the view vertical size to | 
| 123 | .I val. | 
| 124 | .TP | 
| 125 | .BI -vo \ val | 
| 126 | Set the view fore clipping plane at a distance of | 
| 127 | .I val | 
| 128 | from the view point. | 
| 129 | The plane will be perpendicular to the view direction for | 
| 130 | perspective and parallel view types. | 
| 131 | For fisheye view types, the clipping plane is actually a clipping | 
| 132 | sphere, centered on the view point with radius | 
| 133 | .I val. | 
| 134 | Objects in front of this imaginary surface will not be visible. | 
| 135 | This may be useful for seeing through walls (to get a longer | 
| 136 | perspective from an exterior view point) or for incremental | 
| 137 | rendering. | 
| 138 | A value of zero implies no foreground clipping. | 
| 139 | A negative value produces some interesting effects, since it creates an | 
| 140 | inverted image for objects behind the viewpoint. | 
| 141 | This possibility is provided mostly for the purpose of rendering | 
| 142 | stereographic holograms. | 
| 143 | .TP | 
| 144 | .BI -va \ val | 
| 145 | Set the view aft clipping plane at a distance of | 
| 146 | .I val | 
| 147 | from the view point. | 
| 148 | Like the view fore plane, it will be perpendicular to the view | 
| 149 | direction for perspective and parallel view types. | 
| 150 | For fisheye view types, the clipping plane is actually a clipping | 
| 151 | sphere, centered on the view point with radius | 
| 152 | .I val. | 
| 153 | Objects behind this imaginary surface will not be visible. | 
| 154 | A value of zero means no aft clipping, and is the only way to see | 
| 155 | infinitely distant objects such as the sky. | 
| 156 | .TP | 
| 157 | .BI -vs \ val | 
| 158 | Set the view shift to | 
| 159 | .I val. | 
| 160 | This is the amount the actual image will be shifted to the right of | 
| 161 | the specified view. | 
| 162 | This is option is useful for generating skewed perspectives or | 
| 163 | rendering an image a piece at a time. | 
| 164 | A value of 1 means that the rendered image starts just to the right of | 
| 165 | the normal view. | 
| 166 | A value of -1 would be to the left. | 
| 167 | Larger or fractional values are permitted as well. | 
| 168 | .TP | 
| 169 | .BI -vl \ val | 
| 170 | Set the view lift to | 
| 171 | .I val. | 
| 172 | This is the amount the actual image will be lifted up from the | 
| 173 | specified view, similar to the | 
| 174 | .I \-vs | 
| 175 | option. | 
| 176 | .TP | 
| 177 | .BI -vf \ file | 
| 178 | Get view parameters from | 
| 179 | .I file, | 
| 180 | which may be a picture or a file created by rvu (with the "view" command). | 
| 181 | .TP | 
| 182 | .BI -S \ seqstart | 
| 183 | Instead of generating a single picture based only on the view | 
| 184 | parameters given on the command line, this option causes | 
| 185 | .I rhpict | 
| 186 | to read view options from the standard input and for each line | 
| 187 | containing a valid view specification, generate a corresponding | 
| 188 | picture. | 
| 189 | .I Seqstart | 
| 190 | is a positive integer that will be associated with the first output | 
| 191 | frame, and incremented for successive output frames. | 
| 192 | By default, each frame is concatenated to the output stream, but it | 
| 193 | is possible to change this action using the | 
| 194 | .I \-o | 
| 195 | option (described below). | 
| 196 | Multiple frames may be later extracted from a single output stream using the | 
| 197 | .I ra_rgbe(1) | 
| 198 | command. | 
| 199 | .TP | 
| 200 | .BI -o \ fspec | 
| 201 | Send the picture(s) to the file(s) given by | 
| 202 | .I fspec | 
| 203 | instead of the standard output. | 
| 204 | If this option is used in combination with | 
| 205 | .I \-S | 
| 206 | and | 
| 207 | .I fspec | 
| 208 | contains an integer field for | 
| 209 | .I printf(3) | 
| 210 | (eg., "%03d") then the actual output file name will include | 
| 211 | the current frame number. | 
| 212 | .TP | 
| 213 | .BR \-w | 
| 214 | Turn off warning messages. | 
| 215 | .SH EXAMPLE | 
| 216 | rhpict -vp 10 5 3 -vd 1 -.5 0 scene.hdk > scene.pic | 
| 217 | .PP | 
| 218 | rpict -S 1 -o frame%02d.pic scene.hdk < keyframes.vf | 
| 219 | .SH AUTHOR | 
| 220 | Greg Ward | 
| 221 | .SH "SEE ALSO" | 
| 222 | getinfo(1), pfilt(1), pinterp(1), | 
| 223 | printf(3), ra_rgbe(1), rholo(1), rpict(1), rvu(1) |