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root/radiance/ray/src/util/trad.hlp
Revision: 2.5
Committed: Sun Nov 6 09:39:09 1994 UTC (29 years, 4 months ago) by greg
Branch: MAIN
Changes since 2.4: +2 -6 lines
Log Message:
removed small statement about slow help restart

File Contents

# User Rev Content
1 greg 2.1 $Id$
2    
3     This help file is associated with the trad interface to the Radiance
4     rad(1) program. Trad consists of trad.wsh and one do_*.tcl file for
5     each screen. There are currently seven such screens: Action, File,
6     Options, Results, Scene, Views and Zone.
7    
8     .Trad.Intro
9    
10     Trad is a graphical user interface (GUI) to the
11     rad(1) program, which controls the operation of the basic
12     Radiance scene compiling, rendering and picture filtering programs.
13     Trad also includes links to a few utilities for displaying and
14     converting results, but most of what it does can be done by editing a
15     small text file, called the "rad input file".
16     Scene creation still requires the use of a text or graphical editor,
17     or translation from some external CAD format.
18    
19     Trad interaction is broken into seven screens.
20     Each screen is accessed by pressing its associated radio
21     button along the right-hand side of the main window.
22     If trad is started with no file name, the File screen is displayed,
23     and you must pick a valid rad input file before any other screen may
24     be accessed.
25     If a name is given for a file that doesn't exist, trad goes to the
26     Scene screen and prompts you to enter the names of one or more
27     Radiance scene description files.
28     If a rad input file exists already, trad determines if there are
29     renderings still to be done or if everything is finished.
30     If there is still work to be done, trad opens first with the Action
31     screen.
32     If all renderings are complete and up-to-date, trad opens right to
33     Results screen.
34    
35     For additional guidance on Radiance in general, consult the Radiance
36     Tutorial, Reference Manual, and man pages.
37     In particular, it is a good idea to read through the rad(1) man page
38     before using this interface.
39    
40     To find out how to get more help, press the "Next" button to the
41     right.
42    
43     .Trad.Help
44    
45     If you have specific questions about trad, search through the
46     category and topic menus on this help window, or press and release
47     the left mouse button while holding the control key over the object of
48     curiosity in the main trad window.
49     (In general, only active windows are given help file links -- click
50     on these rather than the text labels.)
51 greg 2.5 Additional search capabilities are available over all topics using
52     the "Grep" button.
53 greg 2.1
54     For help on the help facility itself, Control-click on the problem
55     help widget or on the window title in the upper right corner for
56     more general information.
57     (To get back to trad-specific help, press the "HELP" button in the
58     main trad window or Control-click on a trad widget.)
59    
60     .Trad.Messages
61    
62 greg 2.3 Informative messages, commands executed by rad, and errors
63 greg 2.1 appear in the message window at the bottom of the trad frame.
64 greg 2.3 Growing the trad window means growing this message window, and
65 greg 2.1 not much else.
66     This is not really necessary, since the window will be grown
67     automatically if the message requires it.
68    
69     Serious errors will be accompanied by the sounding of the bell.
70    
71     .Trad.Quit
72    
73     To quit the trad application, press the "Quit" button at any time.
74     If you have made changes to the rad input variables, you will be
75     asked prior to program exit if you want to save your changes first.
76    
77     Any batch process running in the background will continue to run,
78     and the associated error messages will be viewable by
79     trad later when you open the same rad input file.
80    
81     .File.Intro
82    
83     This button selects the trad File screen, which allows rad input
84     files to be loaded and saved, and new files to be created.
85    
86     .File.Load
87    
88     This button loads the selected file into trad.
89     If the current file has been changed and these changes have not been
90     saved, you will be given first the opportunity to save your changes.
91    
92     The actual load operation may take several seconds or even minutes,
93     depending on the status of the rendering process.
94     This is because the rad program itself is used to interpret the
95     input file, and if there is no up-to-date octree associated with the
96     file, it is necessary to run getbbox on the entire scene
97     before the variable values can be set.
98     It is possible to eliminate this delay in future loads by going to
99     the Action screen and running oconv.
100    
101     If the opened file has read-only mode set (see chmod(1)), then the
102     "Read Only" check box will be lit.
103     Unchecking this box means that it will be possible to save the file
104     later, though the actual mode on the file will not be changed until
105     it is saved.
106     Loading a writable file always clears the "Read Only" check box.
107    
108     If an error is encountered while trying to load the file, a message
109 greg 2.2 will be printed in the box at the bottom.
110 greg 2.1
111     .File.Save
112    
113     The "Save" button in the File screen saves any changes to the
114     current file.
115     This information is saved in the original file by default, but may
116     be saved in another file by entering a new name in the "File" field.
117     If this new file already exists, a dialogue box will ask if you really
118     want to overwrite it.
119     If the file name is different than the original
120     one loaded, the "Read Only" check box will be ignored.
121    
122     .File.New
123    
124     The "New" button clears all rad variables in preparation for
125     writing a new rad input file.
126     If the file selected already exists, a warning box will ask if you
127     really want to ignore the previous file contents.
128     If you agree, then no warning will be given when the file is later
129     overwritten.
130    
131     .File.ReadOnly
132    
133     The "Read Only" check box permits you to indicate that the opened
134     file should not be overwritten.
135     This box will be checked automatically if the permissions on the
136     edited file do not allow writing by the user.
137     If the box is subsequently unchecked, trad will attempt to change
138     permissions and write to the file when a save is requested.
139     If this fails, an error message will indicate the problem.
140    
141     .Scene.Intro
142    
143     This button selects the trad Scene screen.
144     On this screen, you may enter the octree file and the scene files
145     that go into it, as well as any mkillum or other files on which the
146     scene depends.
147     These files are generally produced by hand in a text editor or by
148     conversion from an external CAD format, such as DXF.
149     (See the Radiance Reference Manual and Radiance Tutorial for details on the
150     information contained in these files.)
151    
152     To enter a file of a particular type, press the corresponding button
153     to get a dialogue box that allows you to pick existing files from any
154     directory.
155    
156     Use the "Discard" button to remove one or more files from a specific
157     list.
158     The actual file is untouched.
159    
160     .Scene.Octree
161    
162     The "Octree" entry in the Scene screen names the octree file to be
163     compiled by oconv from the materials and scene files.
164     (See the oconv(1) man page for more details.)
165    
166     If make(1) is being used to build the octree, you should leave all
167     other windows on this screen empty.
168     The octree can still be rebuilt from trad by pressing the "oconv"
169     or "Force" buttons on the Action screen, but normally it is
170     expected to be current.
171     In particular, an unsupported octree must exist before loading
172     a rad input file on which it depends.
173    
174     The default octree name is the root name from the render input file
175     plus ".oct".
176     If mkillum is being used (i.e. one or more illum files is given),
177     then two additional octrees will be created, named the same except
178     for an additional "0" or "1" immediately before the file suffix
179     (normally ".oct").
180    
181     To delete the named octree, and therefore force the scene to be
182     recompiled and all the pictures to be rerendered, use the "Delete"
183     button next to the octree window.
184    
185     .Scene.OctDelete
186    
187     The "Delete" button next to the octree window removes the named
188     octree from the filesystem, forcing the scene to be later recompiled
189     and all the pictures to be rerendered (if desired).
190     This is appropriate if you add or remove materials, scene or illum
191     files from one or more lists, or make some change to a materials file
192     that requires the octree to be rebuilt (such as adding or removing
193     individual materials).
194    
195     Verification is required before the octree will be deleted.
196    
197     You can achieve the same effect as manually removing the octree by
198     pressing the "Force" button on the scene compilation section
199     of the Action screen.
200     (See the "Force" topic under the "Action" help category for more
201     information.)
202    
203     .Scene.Materials
204    
205     Materials files generally contain Radiance material descriptions
206     only, not geometry.
207     The purpose of listing them separately is so that minor changes to
208     material parameters will not force the octree to be rebuilt,
209     incurring an additional delay that is unnecessary.
210    
211     The "Materials" button is used to add materials files to the list.
212     A dialogue box appears when you press this button and allows you to
213     select files to be included.
214     Each new selection is added to the end of the materials list.
215     The default matching pattern for material files is "*.mat".
216     This may of course be reassigned within the file selection window.
217    
218     The list box showing the current materials may be edited in three
219     ways besides the dialogue for adding files.
220     First, entries may be removed from the list
221     using the "Discard" button.
222     Second, entries may be moved within the box by selecting them with
223     the left mouse button and clicking the middle mouse button over the
224     entry you wish to place the selected items above.
225     If you wish to put the selected items at the very end of the list,
226     click the middle mouse button below the last entry.
227     Third, entries may be moved from other windows by
228     selecting them and pressing the middle button.
229     This works for the list boxes on this screen as well as selections
230     in other windows on the display.
231    
232     The order of materials files is usually unimportant, but sometimes
233     there are definitions in later files that depend on prerequisites in
234     earlier files.
235     An example of this is a window illum source that depends on a sky
236     description file, which must appear before it.
237     The order of files shown in the list is the order they will be given
238     to oconv and therefore to the rendering programs.
239    
240     .Scene.Illum
241    
242     Illum files are Radiance scene descriptions that contain surfaces
243     to be converted into illum sources by mkillum(1).
244     Please consult the manual page for mkillum and understand the
245     Radiance Tutorial before using this box, since these files differ slightly
246     from standard Radiance scene descriptions.
247    
248     The "Illum" button is used to add illum files to the list.
249     A dialogue box appears when you press this button and allows you to
250     select files to be included.
251     Each new selection is added to the end of the illum list.
252     The default matching pattern for material files is "*.rad".
253     This may of course be reassigned within the file selection window.
254    
255     The list box showing the current illum files may be edited in three
256     ways besides the dialogue for adding files.
257     First, entries may be removed from the list
258     using the "Discard" button.
259     Second, entries may be moved within the box by selecting them with
260     the left mouse button and clicking the middle mouse button over the
261     entry you wish to place the selected items above.
262     If you wish to put the selected items at the very end of the list,
263     click the middle mouse button below the last entry.
264     Third, entries may be moved from other windows by
265     selecting them and pressing the middle button.
266     This works for the list boxes on this screen as well as selections
267     in other windows on the display.
268    
269     .Scene.Scene
270    
271     Scene files give the geometry and (perhaps) some of the materials
272     used in a particular Radiance model.
273     These files are given to oconv(1) in the order specified.
274     The ordering of files is usually not important, unless some later
275     files use materials or other modifiers defined in earlier files.
276    
277     The "Scene" button is used to add scene files to the list.
278     A dialogue box appears when you press this button and allows you to
279     select files to be included.
280     Each new selection is added to the end of the scene list.
281     The default matching pattern for material files is "*.rad".
282     This may of course be reassigned within the file selection window.
283    
284     The list box showing the current scene files may be edited in three
285     ways besides the dialogue for adding files.
286     First, entries may be removed from the list
287     using the "Discard" button.
288     Second, entries may be moved within the box by selecting them with
289     the left mouse button and clicking the middle mouse button over the
290     entry you wish to place the selected items above.
291     If you wish to put the selected items at the very end of the list,
292     click the middle mouse button below the last entry.
293     Third, entries may be moved from other windows by
294     selecting them and pressing the middle button.
295     This works for the list boxes on this screen as well as selections
296     in other windows on the display.
297    
298     .Scene.Objects
299    
300     Object files are files on which the given octree depends, but which
301     are not included directly on the oconv command line.
302     If any of these files is modified, then it is assumed that the
303     octree must be rebuilt.
304    
305     To automatically determine which files in the working directory
306     affect the octree, press the "Auto" button just below the "Objects"
307     button.
308     Note that this will only add files to the object list.
309     If you wish to completely replace what is already there, you must
310     therefore select all the files and use the "Discard" button before
311     pressing "Auto".
312    
313     .Scene.Discard
314    
315     The "Discard" button removes the selected file names from a list.
316     The actual files are untouched, of course.
317     (Some care should be taken here, since there is no undo
318     function associated with this window other than reloading the
319     original information with the "Revert" button.)
320    
321     .Scene.Edit
322    
323     Use the "Edit" button to open a text editor on the selected file(s).
324     This is a convenient way to look at and change the contents of the
325     Radiance input files.
326    
327     .Scene.Copy
328    
329     The "Copy" button may be used to selectively copy the scene file
330     information from another rad input file.
331     Specifically, the variables "OCTREE, materials, illum, scene and
332     objects" will be read in to replace the current values.
333    
334     All other variables will be unaffected.
335    
336     .Scene.Revert
337    
338 greg 2.3 The "Revert" button is a convenient way to revert to the original
339 greg 2.1 values in the rad input file.
340     Only the variables on the Scene screen will be affected, but any changes
341     to these variables since the last save will be lost.
342    
343     .Zone.Intro
344    
345     This button selects the trad Zone screen.
346     On this screen, the user should enter the maximum and minimum
347     coordinates of the zone of interest for this set of renderings.
348     This zone need not correspond exactly to any interior or exterior
349     walls, as it is used primarily to set rendering parameters and
350     standard viewpoints.
351    
352 greg 2.3 An interior zone means that standard viewpoints will be selected
353 greg 2.1 from the inside of this box.
354     An exterior zone means that standard viewpoints will be selected
355     from the outside of this box.
356 greg 2.3 The default zone is an exterior one computed from the bounding box
357 greg 2.1 of the entire scene.
358     (Note that this is not usually desirable.)
359    
360     In addition to the ZONE variable, this screen offers the ability
361     to set four other rad variables that are generally associated with a
362     particular scene and a particular zone.
363     These are the rad DETAIL, INDIRECT, VARIABILITY and EXPOSURE
364     variables.
365     For more information on these topics, use the Topic menu or consult
366     the rad manual page.
367    
368     .Zone.Type
369    
370 greg 2.3 There are two types of zones understood by rad, "Interior" and
371 greg 2.1 "Exterior".
372 greg 2.3 An interior zone is indicated when renderings generally take place
373 greg 2.1 inside a specified 3-d box.
374     A typical example might be a single room or auditorium.
375     An exterior zone is indicated when renderings generally take place
376     outside a specified 3-d box, which is the focus of attention.
377     A typical example might be a building exterior or a single object,
378     such as a chair.
379    
380     .Zone.Zone
381    
382     A zone is specified by six real numbers, corresponding to the world
383     coordinates of the box's corners.
384     Zone boxes are always axis-aligned, therefore one need only specify
385     the minimum and maximum X, Y, and Z coordinates.
386    
387     The exact values of these coordinates is not terribly important, as
388     they are only used to guide the setting of certain rendering
389     parameters and standard view positions.
390     It does not matter for instance whether the values lie on the inside
391     or the outside of walls, or if there are non-rectilinear geometries
392     defining the space perimeter.
393     In fact, the whole space may not even be aligned with the X, Y, and Z
394     axes, and a very approximate box may be given.
395     In this case, the standard views may not be very intelligent or
396     useful, but the rendering parameters will still be satisfactory so
397     long as the overall size of the given box is close to the overall
398     size of the space.
399    
400     The Zone entry windows may be manipulated in the following ways.
401     Control-U clears the current window.
402     Control-V pastes the contents of the current selection at the
403     insertion point.
404     Return moves the focus to the next window in the chain.
405    
406     .Zone.Detail
407    
408     The "Detail" setting indicates the relative level
409     of geometric detail in this zone.
410     If the zone is empty except for a few large pieces of furniture, a
411     "Low" setting is indicated.
412     (For an exterior zone, low detail would mean that the object is
413     relatively simple.)
414     If the zone contains a usual amount of furniture and clutter, a
415     "Medium" setting is appropriate.
416     If the zone contains a great many small objects or protrusions, a
417     setting of "High" is indicated.
418    
419     This variable is used by rad to set rendering parameters that are
420     affected by the sizes of objects relative to the overall size of the
421     space.
422    
423     .Zone.Indirect
424    
425     The "Indirect" setting indicates how important indirect illumination
426     is in this space.
427     A setting of "0" means that most light falls directly on visible
428     surfaces, and this setting can be used in most cases.
429     A setting of "1" means that most objects are not directly
430     illuminated by light sources, but receive light only after it has
431     bounced once off some other surface, such as the ceiling.
432     Likewise, a setting of "2" means that light must reflect twice off
433     other surfaces before reaching most objects of interest.
434    
435     Keep in mind that the rendering calculation increases substantially
436     with each increment to this variable, so it is a good idea to use
437     the smallest reasonable value.
438    
439     .Zone.Variability
440    
441     The "Variability" setting gives a qualitative indication of how
442     light varies in magnitude over surfaces in this zone.
443     In a typical direct or indirect lighting situation, this variable
444     would be set to "Low", indicating that light is fairly uniform
445     throughout the space.
446     If there are some areas that are much better lit than others, such
447     as desks with powerful tasks lights in a room with dimmer ambient
448     lighting, a "Medium" setting is appropriate.
449     If there is direct sunlight entering the room, casting bright
450     patches on some surfaces and not others, then a setting of "High" is
451     indicated.
452    
453     Note that this variable speaks to the magnitude of light variations
454     more than the patterns of light.
455     It may well be that the light is casting interesting patterns such
456     as scallops on the walls or something, but as long as the variations
457     in brightness are less than an order of magnitude or so, it is a low
458     variability situation.
459     The high variability
460     example given above of direct sun entering a space corresponds to a
461     a variation in brightness of about three orders of magnitude, or
462     1,000 to 1!
463    
464     .Zone.Exposure
465    
466     The "Exposure" setting gives the multiplier between the initial
467     radiance values at each pixel (in watts/steradian/meter^2) to the
468     display pixel values (in the range of 0-1, where 0 is black and 1 is
469     the maximum monitor output).
470     This setting also determines the average "ambient level," which is
471     an important parameter for rendering accuracy.
472    
473     There are two basic ways to compute the exposure value.
474     The first is by trial and error, where the value is adjusted up and
475     down within rview using the "e = value" command.
476     Though it sounds flaky, this is the most reliable way to set the
477     exposure (and ambient level) in general lighting situations.
478    
479     The second method is using a zonal cavity approximation.
480     For this, you must estimate the total light flux entering the zone
481     from light sources and windows, and the total illuminated area.
482     (This applies to interior zones, only. For exterior zones, use the
483     value suggested by gensky in its output.)
484     In addition, you must approximate the area-weighted average
485     reflectance of the illuminated surfaces.
486     The formula then for the exposure multiplier using this information
487     is: pi*tot_area*(1-avg_refl)/(2*tot_flux*avg_refl)
488     where pi is 3.1416, tot_area is given in square meters and
489     tot_flux is given in watts.
490     (Divide total lumens by 179 lumens/watt to get watts.)
491    
492     The exposure value may either be given as a positive real value, or
493     as a real value preceeded by a '+' or '-' indicating a positive or
494     negative number of f-stops (powers of two) from the original value.
495    
496     If no exposure is given, pfilt will automatically compute the
497     average for each image, and a default ambient level of 10 will be
498     used for exterior zones and 0.01 for interior zones.
499    
500     .Zone.Copy
501    
502     The "Copy" button on the Zone screen takes all values for this
503     screen from another rad input file, replacing the current values.
504 greg 2.3 Specifically, the rad variables "ZONE, DETAIL, INDIRECT,
505 greg 2.1 VARIABILITY and EXPOSURE" will be copied from the named file.
506    
507     All other variables will be left untouched.
508    
509     .Zone.Revert
510    
511 greg 2.3 The "Revert" button is a convenient way to revert to the original
512 greg 2.1 values in the rad input file.
513     Only the variables on the Zone screen will be affected, but any changes
514     to these variables since the last save will be lost.
515    
516     .Views.Intro
517    
518     This button selects the trad Views screen.
519     This screen provides a means of setting the multi-valued
520     "view" variable.
521     Each view setting is listed by name, or by number if no name has
522     been assigned.
523 greg 2.3 To add a new view, enter a unique name and specify the view
524 greg 2.1 options,
525     then press the "Add" or "Set Default" button.
526     If a view with the same name already exists, it is unconditionally
527     overwritten.
528     To modify a particular view, simply select it, change its name
529     and/or parameters, and press the "Change" button.
530     To remove an unwanted view, select it and press the "Delete" button.
531     To undo this action, simply press the "Add" button again.
532    
533 greg 2.3 The first view in the list is the default given to rview during
534 greg 2.1 interactive rendering, and is the first view rendered in a batch run.
535     To change the default view, select the newly desired view and press
536     the "Set Default" button.
537     This button also acts like the "Add" button inasmuch as a new view
538     may be entered and this button will add it and make it the default
539     at the same time.
540    
541     The Views screen also allows the standard view up vector to be
542     changed, as well as the root picture name and the output resolution.
543    
544     .Views.List
545    
546     The list box on the far left of the Views screen shows the
547     currently defined view names.
548     Clicking on any of these with the left mouse button shows the view
549     parameters and allows the view to be edited.
550    
551     To change the name or options, edit the "Name" or "Options"
552     entry and click on the "Change" button.
553    
554     Use the "Add" button to add a new view, which may be modified from
555     an old one by changing the name and options.
556    
557     Use the "Delete" button to delete the selected view from the list.
558    
559     Views are listed in the order in which they appear in
560     the rad input file.
561    
562     The standard view is "X" is used if no views are specified.
563    
564     .Views.Name
565    
566     Each view has a unique name, which may be chosen at the user's
567     discretion or taken from a list of standard views, described below.
568 greg 2.3 An invented name should be kept as short as possible, since it is
569 greg 2.1 added to the picture file name along with the standard ".pic" suffix.
570    
571     The standard views are specified by strings of the form
572     "[Xx]?[Yy]?[Zz]?[vlah]?".
573     (That is, an optional upper or lower case X followed by an optional
574     upper or lower case Y followed by an optional upper or lower case Z
575     followed by an optional lower case V, L, A or H.)
576     The letters indicate the desired view position, where upper case "X"
577     means maximum X, lower case "y" means minimum Y and so on.
578     The final letter is the view type, where 'v' is perspective (the
579     default), 'l' is parallel, 'a' is angular fisheye, and 'h' is
580     hemispherical fisheye.
581 greg 2.3 A perspective view from maximum X, minimum Y would be "Xy" or
582 greg 2.1 "Xyv".
583     A parallel view from maximum Z would be "Zl".
584     If "ZONE" is an interior zone, the standard views will
585     be inside the perimeter.
586     If it is an exterior zone, the standard views will be outside.
587     Note that the standard views are best used as starting points,
588     and additional arguments may be given after the
589     identifier to modify a standard view to suit a particular model.
590    
591     .Views.Options
592    
593     The "Options" entry window is where the Radiance view
594     corresponding to the selected name is given.
595     If the view is one of the standard names (described in the "Views
596     Name" section), then the options are truly optional, and will
597     modify the standard view.
598     Otherwise, it is usually necessary to specify a set of options to
599     define a view.
600    
601     The simplest view specification is of the form "-vf viewfile", where
602     "viewfile" is a file created with the rview "view" command, or a
603     Radiance picture.
604     This method of naming views, although convenient, is not the best
605     since it is difficult to know exactly where such a view is by
606     seeing only its file name.
607     Also, the file may change or be moved or removed, and then the view
608     may be different than expected or gone altogether.
609    
610     To add view options selected from another X11 window, select the
611     text from another window in the normal fashion, use the left mouse
612     button to click on the insertion point in the options string, then
613     use Control-V to insert the text at that point.
614     For convenience, the middle mouse button has been made
615     equivalent to Control-V in this window, but it is not the normal
616     interaction mode for trad.
617    
618     Consult the rpict(1) manual page for a full description of the various
619     view options, all of which begin with "-v".
620     Just briefly, the "-vt?" option sets the view type, where "?" is
621     replaced by one of the letters "v, l, a or h", corresponding to
622     perspective, parallel, angular and hemispherical fisheye, respectively.
623 greg 2.3 The "-vp x y z" option sets the view position (eyepoint), where "x y z"
624 greg 2.1 is replaced by the position in 3-space.
625     The "-vd xd yd zd" option sets the view direction, where "xd yd zd"
626     is a vector pointing in the desired direction.
627     (To compute this direction from a "look-at" point, simply subtract
628     the eyepoint from the look-at point. Vector normalization is
629     unnecessary.)
630     The "-vh horiz" and "-vv vert" options set the horizontal and
631     vertical view sizes, respectively.
632 greg 2.3 For perspective views, these correspond to full camera angles in
633 greg 2.1 degrees.
634     For parallel views (using the "-vtl" option), they correspond to
635     image plane size in world coordinates.
636     The lesser used "-vu xd yd zd", "-vs vs" and "-vl vl" options
637     will not be discussed here.
638    
639     The order of the view options is irrelevant, unless the same option
640     is given twice, in which case the last one is used.
641     Trad does not check the syntax of the view options strings, so be
642     careful!
643     In particular, make sure that each option and each argument has a
644     space between it and whatever follows.
645    
646     Hitting return in the "Options" window is equivalent to pressing the
647 greg 2.4 "Add" button followed by the "Clear" button.
648 greg 2.1
649     .Views.Add
650    
651     The view "Add" button takes the currently defined view given by the
652     "Name" and "Options" windows and appends it to the list of views.
653     If another view by the same name exists, it is removed first.
654    
655     Since the view is added to the end of the "Views" list, the "Add"
656     button is a convenient way to move views to a lower-priority
657     position.
658     Simply select the view you wish to be last and press "Add".
659    
660     To add a view as the first (i.e. the default) view instead of the
661     last, use the "Set Default" button.
662    
663     .Views.Change
664    
665     The view "Change" button deletes the currently selected view and
666     adds the currently defined view in its place, changing the name
667     and/or view options in the process.
668    
669     .Views.Delete
670    
671     The view "Delete" button removes the currently selected view from
672     the view list.
673    
674     To undo this action, simply press the "Add" button immediately
675     afterwards, while the deleted view is still present in the edit
676     window.
677    
678     .Views.Clear
679    
680     The "Clear" button simply clears the "Name" and "Options" windows
681     for the convenience of entering a new view.
682     It has no effect on the rad input variables.
683    
684     Note that Control-U will always clear an entry box whose cursor is
685     active.
686    
687     .Views.Default
688    
689     The "Set Default" button may be used to make the selected view the
690     default view for rendering.
691     This simply moves the view to the top of the list in the rad input file.
692     The default view will be the one normally rendered by rview when rad
693     is started interactively, and is the first view rendered in a batch
694     process.
695    
696     A new view may be added as the default view by pressing the "Set
697     Default" button rather than the "Add" button.
698     It is never necessary to press both.
699    
700     If the selected view is already the default, this button will be
701     disabled and will read "Is Default" instead of "Set Default".
702    
703     .Views.Up
704    
705     The standard view up vector may be set to the positive X axis (+X),
706     the positive Y axis (+Y), the positive Z axis (+Z), the negative
707     X axis (-X), the negative Y axis (-Y), or the negative Z axis (-Z).
708    
709     This setting may always be overriden by the "-vu xd yd zd" option,
710     and will be altered for a particular view if it happens to be
711     parallel to the view direction.
712    
713     .Views.Picture
714    
715     The root picture file name is given in the "Picture" entry window.
716     To this will be added an underscore, followed by the name of
717     the particular view being rendered, followed by the ".pic" suffix.
718    
719     To render pictures into a different directory than the one
720     containing the rad input file, simply precede the file name by a
721     relative or absolute directory.
722     (Do not use the tilde shorthand for home directories,
723     as it is not guaranteed to work on all systems.)
724    
725     The default picture name is the root name of the rad input file.
726    
727     .Views.Resolution
728    
729     The final picture resolution is set in the "Resolution" entry
730     window.
731     The first entry is the X resolution (in pixels), and the second
732     (optional) entry is the Y resolution.
733     If there is only one entry, the maximum X and Y resolution will be
734     equal.
735     If a third entry is given, it is taken as the aspect ratio of the
736     destination pixels.
737     A number greater than one means that the pixels on the destination
738     device are taller than they are wide (and therefore there are more
739     of them horizontally than vertically spanning a like distance), and
740     a number less than one means the opposite.
741     An aspect ratio of zero means that the exact given X and Y
742     dimensions are to be honored, whatever the resulting pixel ratio.
743     Normally, either the X or the Y resolution is reduced as necessary
744     to maintain a specific pixel aspect ratio (1 by default).
745    
746     The default value for this variable is "512".
747    
748     .Views.Copy
749    
750     The "Copy" button in the Views screen permits those variables
751     represented on this screen to be copied from another rad input file.
752     Specifically, the affected variables are "view, UP, PICTURE, and
753     RESOLUTION".
754    
755     The original values will be lost, and all other variables will be
756     untouched.
757    
758     .Views.Revert
759    
760 greg 2.3 The "Revert" button is a convenient way to revert to the original
761 greg 2.1 values in the rad input file.
762     Only the variables on the Views screen will be affected, but any changes
763     to these variables since the last save will be lost.
764    
765     .Options.Intro
766    
767     This button selects the trad Options screen.
768     This screen allows the setting of various options for
769     controlling the rendering process.
770     The most general option is rendering "Quality", which determines the
771     overall accuracy and beauty of the pictures produced.
772     A separate "Penumbras" option indicates the importance of soft
773     shadows in this scene.
774     The "Ambfile" variable allows you to specify a file for sharing
775     ambient files between runs, and it is recommended that you set
776     this variable for high quality renderings.
777     The "Optfile" variable allows you to specify a separate file for
778     storing rendering options, which reduces the size of the command
779     line and makes it easier to run programs such as rtrace(1).
780     The "Report" variable may be used to specify a time interval (in
781     minutes) between progress reports.
782    
783     Other windows allow the user to customize the options to oconv(1),
784     mkillum(1), rview(1) and rpict(1), and pfilt(1).
785    
786     .Options.Quality
787    
788     The "Quality" setting affects the overall accuracy and beauty of the
789     renderings produced.
790    
791     A "Low" setting is appropriate for quick checks of scene geometry and
792     crude lighting studies.
793     No interreflection calculation will take place, regardless of the
794     setting of the "INDIRECT" variable, and other options are tuned for
795     speed over accuracy.
796     The computed picture size will exactly equal the final picture
797     size, thus some aliasing may be apparent.
798    
799     A "Medium" quality setting is most often used for draft renderings, as
800     it provides a good balance between rendering time and accuracy.
801     The number of interreflections calculated will be equal to the
802     setting of the "INDIRECT" variable.
803     The computed picture size will be twice the final size, for a modest
804     degree of anti-aliasing.
805    
806     A "High" quality setting is usually reserved for final renderings.
807     The number of interreflections computed will equal the value of the
808     "INDIRECT" variable plus one, to guarantee accuracy.
809     The computed picture size will be three times the final size, so
810     aliasing artifacts should be negligible.
811    
812     When increasing the value of the "Quality" setting, it is usually a
813     good idea to delete the old "Ambfile", if there is one.
814     (See the "AmbDelete" topic under the current help category for
815     details.)
816    
817     .Options.Penumbras
818    
819 greg 2.3 The "Penumbras" setting determines whether or not Radiance will
820 greg 2.1 make a special effort to generate soft shadows from area light sources.
821     Since this is a potentially expensive calculation, penumbras should
822     only be switched "On" when they are really needed.
823    
824     Leaving this setting "Off" does not mean that area light sources
825     will be treated as points.
826     It only means that some accuracy and possibly some smoothness
827     will be traded for speed in the shadow calculations.
828    
829     .Options.Ambfile
830    
831     The "Ambfile" is the file used to store Radiance ambient values for
832     later reuse in other renderings.
833     This can greatly reduce the time required to generate multiple
834     views, as well as improve the quality of a single view whenever
835     interreflections are computed.
836    
837     It is strongly recommended that the user set this variable, especially
838     when the "QUALITY" variable is set to "High".
839     The usual convention is to use the root name of the rad input file,
840     followed with the ".amb" suffix.
841     It is generally not a good idea to share ambient files between
842     different zones, as the placement and accuracy of these values will
843     vary according to the location and characteristics of each zone.
844    
845     .Options.AmbDelete
846    
847 greg 2.3 The "Delete" button next to the "Ambfile" window on the Options
848 greg 2.1 screens allows you to remove the named ambient file.
849     This is usually done when a change to one or more rad variables
850     casts doubt on the accuracy of the values stored in this file.
851     In particular, increases in the variables, "DETAIL, INDIRECT,
852     VARIABILITY, EXPOSURE or QUALITY" generally invalidate this file.
853    
854     If the ambient file is not empty, you will be asked to verify this
855     operation since the values may represent a significant computational
856     effort.
857    
858     .Options.Optfile
859    
860     The "Optfile" setting assigns a file to hold rendering options,
861     which may be a convenience when these options are reused for
862     rtrace(1) or rpiece(1), or manual invocations of rview or rpict.
863     Using an options file also reduces the size of the command line,
864     making it a little easier on the eye.
865    
866     To assure that the "Optfile" contents are up-to-date, you should press
867     the "oconv" or "Script" button on the Action screen.
868    
869     .Options.Report
870    
871     The "Report" setting indicates the time interval (in minutes)
872     between rpict progress reports.
873     Normally, rpict runs silently, but it is often nice to know how far
874     a given rendering has progressed.
875     Normally, progress reports and errors during batch renderings
876     are sent to the error file given by the root of the rad input
877     file name followed by the ".err" suffix.
878     (See the "Errors" topic under the "Action" screen category.)
879     If you wish these reports and errors to be directed to a different
880     file, follow the time interval by a space and a file name.
881    
882     No setting on this variable means do not report rendering progress.
883 greg 2.3 A zero setting means the same thing, and may be used when a
884 greg 2.1 separate error file is desired but progress reports are not.
885    
886     .Options.Oconv
887    
888     The "oconv opts" window may be used to specify any additional
889     options to the oconv(1) command used to compile the scene
890     description.
891    
892     In particular, the "-f" option for creating a "frozen" octree may
893     speed rendering start-up substantially, although it makes it
894     impossible to change even material properties without
895     recompiling the scene again.
896     (The "-f" option is technically incompatible with naming
897     "materials" files on the Scene screen.)
898    
899     If oconv generates a "set overflow" error, it may mean that the "-r
900     res" option is needed to increase the octree resolution.
901     See the oconv(1) man page for details.
902    
903     The "-i octree" option should be used with extreme caution, as incremental
904     building of octrees is not very well supported by rad.
905     You may do it this way if you specify the input octree as one of the
906     "Objects" files on the Scene screen, but it is preferable to use the
907     UNIX make(1) utility to incrementally build the octree instead, and
908     indicate this by not specifying any illum or scene files.
909    
910     .Options.Mkillum
911    
912     The "mkillum opts" window may be used to specify options to the
913     mkillum(1) command, whose options are actually passed to rtrace(1).
914     These options apply only if there are one or more "Illum" files
915     named on the Scene screen.
916    
917     It is very important to set mkillum options sensibly,
918     since rad does not have the intelligence to do it for you.
919    
920     .Options.Render
921    
922     The "render opts" window is used to specify additional options to
923     the rview(1) and rpict(1) rendering programs.
924 greg 2.3 Most of the important parameters are computed by rad, so this
925 greg 2.1 window is usually used to override specific parameters or to give
926     additional information, such as which materials to exclude from the
927     interreflection calculation.
928    
929     .Options.Pfilt
930    
931     The "pfilt opts" window is used to specify additional options to
932     the pfilt(1) picture filtering program.
933    
934     Note that the "-e expval", "-x xres" and "-y yres" options are
935     already dictated by the settings of the "EXPOSURE" and "RESOLUTION"
936     variables, and should therefore be used with caution.
937    
938     Also note that the setting of some pfilt options require a
939     two-pass filtering process, rather than the default single pass.
940     If no "EXPOSURE" setting is given, this is not a problem, but if a
941     value for the "EXPOSURE" variable is set as recommended, then it is
942     necessary to manually specify the "-2" option to pfilt, followed by
943     an exposure that undoes the "EXPOSURE" setting.
944     An equivalent workaround is to unset the EXPOSURE variable and
945     manually set the render option "-av V V V", where "V" is equal to
946     0.5/old_EXPOSURE.
947    
948     .Options.Copy
949    
950     The "Copy" button in the Options screen permits those variables
951     represented on this screen to be copied from another rad input file.
952     Specifically, the affected variables are "QUALITY, PENUMBRAS,
953     AMBFILE, OPTFILE, REPORT, oconv, mkillum, render and pfilt".
954    
955     The original values will be lost, and all other variables will be
956     untouched.
957    
958     .Options.Revert
959    
960     The "Revert" button is a convenient way to revert to the original values
961     in the rad input file.
962     Only the variables on the Options screen will be affected, but any changes
963     to these variables since the last save will be lost.
964    
965     .Action.Intro
966    
967     This button selects the trad Action screen.
968     This screen is where the actual Radiance programs are
969     run, usually via rad(1).
970     The top row of buttons is used to update the octree following a
971     change to one or more input files.
972     The "rview" button starts an interactive rendering in the
973     foreground.
974     The next set of buttons provides for the control of a batch
975     rendering process, taking place in the background.
976     Finally, the bottom set of buttons allows you to preview what would
977 greg 2.3 happen during a batch rendering, or (equivalently) make a script of
978 greg 2.1 UNIX commands for later execution.
979    
980     When the Action screen is first brought up, the message window
981     displays the current status of any batch rendering process.
982     The status must either be "No batch rendering in progress," which
983     means that as far as trad can tell a batch rendering was never
984     started, "Batch rendering stopped," meaning that there is no current
985     process but at least some views have not been rendered or are
986     out-of-date, or "Batch rendering finished," meaning that everything
987     is done.
988    
989     .Action.Oconv
990    
991     The "oconv" button on the Action screen may be used to manually
992     compile the scene description and bring the octree up to date.
993     It is normally not necessary to use this button, since the octree
994     will be rebuilt if appropriate prior to rendering.
995     However, if the octree is maintained by make(1) rather than rad, or
996     the octree was never created and you want trad to start a little
997     faster next time, or you just need the octree for some reason other
998     than rendering, this is the button for you.
999    
1000     If you have made changes to the rad variables or the Radiance
1001     material files that invalidate the current octree or renderings but
1002     would not automatically rebuild the octree because the scene files
1003     themselves were not changed, it may be wise to use the "Force"
1004     button.
1005     In contrast, if you have made some insignificant changes to the
1006     scene files that should not make any difference to the octree or the
1007     renderings, you may want to use the "Touch" button.
1008    
1009     Pressing the "oconv" button also updates the contents of the
1010     "Optfile" if one is given on the Options screen.
1011     This may be useful for computing rendering parameters for rtrace(1)
1012     or rpiece(1).
1013    
1014     .Action.Force
1015    
1016     The "Force" button on the Action screen
1017     causes the octree to be unconditionally rebuilt,
1018     by removing it first.
1019     This will also require all pictures to be rerendered, so only use
1020     this button if it is really necessary, i.e. if you have made
1021     some important changes to the rad
1022     variables on the Scene, Zone or Options screens, but have not
1023     changed any scene file on which the octree depends.
1024    
1025     If the octree itself should not be affected by these changes, only
1026     the renderings, you may delete the faulty picture files instead from
1027     the Results screen and the ambient file (if it exists) from the
1028     Options screen.
1029    
1030     .Action.Touch
1031    
1032     The "Touch" button on the Action screen
1033     should be used when some insignificant change has
1034     been made to the Radiance input files, which might otherwise cause
1035     the octree to be rebuilt and the picture files to be rerendered.
1036    
1037     Care should be exercised in using this button since you may have
1038     made a change that really does affect the octree in an important
1039     way.
1040     Even something as seemingly trivial as deleting an unused material
1041     will cause an unfrozen octree to become invalid and unusable.
1042    
1043     Therefore, if you know the octree should be rebuilt, but you do not
1044     want to cause any of the currently rendered pictures to be redone,
1045     press the "oconv" button to bring the octree up to date, followed
1046     by the "Touch" button.
1047     (This will still cause the ambient file to be removed,
1048     unfortunately.)
1049    
1050     .Action.Rview
1051    
1052 greg 2.3 The "rview" button on the Action screen starts an interactive
1053     rendering for the selected view, indicated by the menu button
1054 greg 2.1 just to the right.
1055 greg 2.3 Other views may be accessed within rview using the "L name"
1056     command, and new views can be added with the "V name"
1057 greg 2.1 command.
1058 greg 2.3 (See the rview(1) man page and the "View" topic in the current
1059 greg 2.1 help category for more information.)
1060    
1061 greg 2.3 If the octree is out-of-date, it will be rebuilt before rendering
1062 greg 2.1 begins.
1063    
1064     .Action.View
1065    
1066     The Action screen contains two menus for selecting views.
1067 greg 2.3 The top menu, next to the "rview" button, sets the view to start
1068 greg 2.1 with in rview, and is selected from the current view list.
1069 greg 2.3 The second view menu, next to the "Start" button for batch
1070 greg 2.1 rendering, selects the view or views to render in batch mode.
1071 greg 2.3 If the special entry "ALL" is selected, then every view in the
1072 greg 2.1 current list will be rendered if it hasn't been already.
1073    
1074 greg 2.3 The batch rendering view menu also selects the view or views
1075 greg 2.1 to use in producing a script during a dry run.
1076    
1077     .Action.Start
1078    
1079 greg 2.3 The "Start" button for batch rendering on the Action screen
1080     initiates a rad rendering process in the background using the
1081 greg 2.1 selected view or views shown on the menu button to the right.
1082    
1083     If any of the rad variables have been changed since the
1084     file was last saved, you will first be asked if you wish to save
1085     your changes before starting a background process.
1086     If you discard these changes, then the batch rendering will be
1087     conducted using the previously saved values.
1088    
1089 greg 2.3 Once a background process is going, the "Start" button is
1090     disabled, and rendering progress can be monitored by checking
1091 greg 2.1 the error file periodically.
1092 greg 2.3 (This file is named by the root of the rad input file followed by
1093 greg 2.1 ".err".)
1094 greg 2.3 When a batch process is started or already running, this button
1095 greg 2.1 will be disabled.
1096    
1097 greg 2.3 The background process can be killed during this or later
1098 greg 2.1 invocations of trad using the "Kill" button.
1099    
1100     .Action.Kill
1101    
1102 greg 2.3 The batch rendering "Kill" button kills the
1103 greg 2.1 background process started earlier with the "Start" button.
1104 greg 2.3 The rad process id is taken from the first line of the error file,
1105 greg 2.1 and this process and all its children are killed when the
1106     button is pressed.
1107    
1108 greg 2.3 So long as there is an ambient file specified in the Options
1109     screen, no data is lost by killing and restarting a batch
1110 greg 2.1 rendering, though some new startup costs will be incurred.
1111    
1112 greg 2.3 The "Kill" button is disabled if no running batch process is
1113 greg 2.1 detected.
1114    
1115     .Action.CheckErr
1116    
1117     Pressing the "Check errors" button
1118 greg 2.3 displays the contents of the batch rendering error file, named
1119     by the root of the current rad input file followed by the ".err"
1120 greg 2.1 suffix.
1121 greg 2.3 This file will contain the command lines executed by rad so far,
1122     and may or may not contain additional progress reports from
1123 greg 2.1 rpict, depending on the initial setting of the "REPORT" variable.
1124    
1125     If no error file exists, this button will be disabled.
1126    
1127     .Action.Script
1128    
1129     The dry run "Script" button runs rad with the
1130 greg 2.3 "-n" option so that you may see the commands that would be
1131 greg 2.1 executed during a batch run without actually executing them.
1132 greg 2.3 If a file is named in the window next to this button, the output
1133 greg 2.1 will simply be written to that file.
1134 greg 2.3 If no file is named, a temporary file is created and an editor
1135 greg 2.1 window is opened on it.
1136    
1137     Producing a dry run also writes the "Optfile" if one is specified
1138     on the Options screen.
1139     This may be useful for computing rendering parameters for rtrace(1)
1140     or rpiece(1).
1141    
1142 greg 2.3 The view or views are selected by the same menu used for
1143 greg 2.1 batch rendering.
1144 greg 2.3 (See the "View" topic under the current help category for more
1145 greg 2.1 information.)
1146    
1147     .Action.Edit
1148    
1149 greg 2.3 The dry run "Edit" button is used to edit the named script file
1150 greg 2.1 created by pressing the "Script" button.
1151     If no file is named, this button is ineffective.
1152    
1153     .Action.Delete
1154    
1155 greg 2.3 The "Delete" button removes the named script file, created by the
1156 greg 2.1 "Script" button.
1157 greg 2.3 If no file is named, or the named file does not exist, this button has
1158 greg 2.1 no effect.
1159    
1160     .Results.Intro
1161    
1162     This button selects the trad Results screen.
1163 greg 2.3 This screen permits rendered pictures to be displayed,
1164 greg 2.1 converted to other image formats, and printed.
1165 greg 2.3 Only finished pictures may be converted or printed, but
1166     incomplete pictures (i.e. aborted renderings or renderings in
1167 greg 2.1 progress) may be displayed interactively.
1168    
1169     The left-hand window shows a list of completed views, and the
1170 greg 2.3 right-hand window shows views that have been started but not
1171 greg 2.1 finished.
1172 greg 2.3 Note that other views may not even be started, thus may not
1173 greg 2.1 appear in either list.
1174 greg 2.3 Also, just because a view appears on the Results screen, it does
1175     not mean that view is up-to-date with respect to the Radiance
1176 greg 2.1 input files.
1177 greg 2.3 (The best way currently to tell which pictures are out-of-date
1178     is to press the "Script" button on the Action screen and examine
1179 greg 2.1 the output.)
1180    
1181     .Results.Finished
1182    
1183     The "Finished views" list box on the Results screen shows those
1184     renderings which have completed, whether or not they are up-to-date
1185     with respect to the Radiance input files.
1186     Select pictures in this box for display, conversion to other image
1187     formats, and/or printing.
1188     Selected pictures may also be deleted with the "Delete" button.
1189    
1190     To select one or more pictures from this box, click the left mouse
1191     button on a view name, and drag it up or down to select multiple
1192     views.
1193     Shift-click also allows views to be added to the selection.
1194    
1195     .Results.Unfinished
1196    
1197     The "Unfinished views" list box on the Results screen shows those
1198     renderings which have not yet completed.
1199     These partial pictures may or may not be out-of-date
1200     with respect to the Radiance input files.
1201     Select pictures in this box for display or deletion.
1202     It is not possible to convert or print an unfinished picture.
1203    
1204     To select one or more pictures from this box, click the left mouse
1205     button on a view name, and drag it up or down to select multiple
1206     views.
1207     Shift-click also allows views to be added to the selection.
1208    
1209     .Results.Rescan
1210    
1211 greg 2.3 The "Rescan" button on the Results screen is used to update the
1212     finished and unfinished view lists, in case one or more pictures
1213 greg 2.1 has completed since the Results screen was brought up.
1214    
1215     .Results.Delete
1216    
1217     The "Delete" button on the Results screen is used to remove the
1218     selected picture files from the filesystem.
1219     Verification is required before any action is taken.
1220    
1221     .Results.Display
1222    
1223     The "Display" button on the Results screen may be used to display
1224     the selected images using ximage(1) or any other Radiance picture
1225     display program.
1226    
1227     The current display command is shown in the adjacent command window,
1228     and may be customized if necessary.
1229     (See the "DispCommand" topic in the current help category for
1230     details.)
1231    
1232     .Results.DispCommand
1233    
1234     The current display command in the Results screen determines how
1235     finished and unfinished Radiance pictures will be displayed.
1236     This command contains two variable fields.
1237     The first field is a signed integer, indicated by the "%+d" format.
1238     The second field is a string, indicated by the "%s" format.
1239     Both fields must appear in any display command used, and must be in
1240     this order on the command line.
1241     The first field is used to adjust the exposure of an unfinished
1242     picture, and the second field is the file name.
1243     The rest of the command is arbitrary, so long as it is understood by
1244     the system.
1245    
1246     The default command is "ximage -e %+d %s >& /dev/null &", which
1247     executes ximage in the background and sends any output (including
1248     error messages) to the null device.
1249     If you don't wish ximage to run in the background, you may remove
1250     the last part of the command (" >& /dev/null &").
1251    
1252     .Results.Convert
1253    
1254     The "Convert" button on the Results screen converts the selected
1255     pictures to the format indicated on the menu button to the right.
1256     (See the "ConvType" topic under the current help category for
1257     details.)
1258    
1259     Each finished picture is converted to the selected format and given
1260     the name indicated by the adjacent window labeled "File".
1261     (See the "ConvFile" topic under the current help category for
1262     details.)
1263    
1264     .Results.ConvType
1265    
1266     The image type button on the Results screen determines the
1267     destination format for converted Radiance pictures.
1268     You may choose from the list that pops up when you press this
1269     button.
1270     Often, a given format may have more than one subtype.
1271     In general, 8-bit means 8-bit color with a lookup table,
1272     B&W means 8-bit greyscale with no lookup, and 24-bit means 24-bit
1273     true color.
1274    
1275     The file suffix is determined by the basic conversion type, but may
1276     be changed along with the rest of the name by editing the file name
1277     window.
1278     (See the "ConvFile" topic under the current help category for
1279     details.)
1280    
1281     .Results.ConvFile
1282    
1283     The image conversion file name window on the Results screen should contain
1284     a single "%s" format field, which will be replaced by the view name
1285     being converted.
1286    
1287     The default name is the same as the value of the rad "PICTURE"
1288     variable, followed by a suffix appropriate to the selected file type.
1289    
1290     .Results.Print
1291    
1292     The "Print" button on the Results screen executes the given
1293     system command to print one copy each of the selected picture(s).
1294     This button does not work on unfinished pictures.
1295    
1296     The actual command used for printing may be edited in the adjacent
1297     window.
1298     (See the "PrintCommand" topic under the current help category for
1299     details.)
1300    
1301     .Results.PrintCommand
1302    
1303     The print command window on the Results screen contains the system
1304     command to use in printing out finished Radiance pictures.
1305     The "%s" format field, which must appear somewhere in the command,
1306     is replaced by the selected Radiance picture file name(s).
1307    
1308     The default command is "ra_ps %s | lpr", which converts the Radiance
1309     picture to a black and white PostScript file and sends it to the lpr
1310     print spooler.
1311     If your printer does not understand PostScript, or your system does
1312     not support lpr, this command must obviously be changed.