Rayfront User Manual

Preview a Simulation on Unix

The previewer program rview(1) starts rendering the image from the selected viewpoint and gradually improves the resolution of the display until interrupted by keyboard input. Rview(1) then issues a prompt (usually ':') and accepts a command line from the user. Rview(1) may also stop its calculation and wait for command input if the resolution of the display has reached the resolution of the graphics device. At this point, it will give the 'done:' prompt and await further instructions. If rview(1) runs out of memory due to lack of resources to store its computed image, it will give the 'out of memory:' prompt. At this prompt, the user can save the image, quit, or even restart a new image, although this is not generally recommended on virtual memory machines for efficiency reasons.

Rview(1) is not meant to be a rendering program, and we strongly recommend that you start a background simulation instead for that purpose. Since background simulations don't store the image in memory or update any display of the output, they are much faster and less wasteful of its resources than rview(1). Rview(1) is intended as a quick interactive program for deciding viewpoints and debugging scene descriptions and is not suited for producing polished images

Interactive Commands

Once the program starts and the window has the focus, a number of commands can be used to control it. A command is given by its name, which can be abbreviated, followed by its arguments. Arguments in square brackets "[...]" are optional.

aim [ mag [ x y z ] ]

Zoom in by the magnification mag on point x y z. The view point is held constant; only the view direction and size are changed. If x y z is missing, the cursor is used to select the view center with a left click. A negative magnification factor means zoom out. The default factor is one.

^C

Interrupt. This temporarily stops the simulation. Pressing <return> or entering any other command will resume the simulation.

exposure [ spec ]

Adjust exposure. The number spec is a multiplier used to compensate the average exposure. A value of 1 renormalizes the image to the computed average, which is usually done immediately after startup. If spec begins with a '+' or '-', the compensation is interpreted in f-stops (ie. the power of two). If spec begins with an '="'," an absolute setting is performed. An '="'" by itself permits interactive display and setting of the exposure. If spec begins with an '@', the exposure is adjusted to present similar visibility to what would be experienced in the real environment. If spec is absent, or an '@' is followed by nothing, then the cursor is used to pick a specific image location for normalization.

frame [ xmin ymin xmax ymax ]

Set frame for refinement. If coordinates are absent, the cursor is used to pick frame boundaries. If "all" is specified, the frame is reset to the entire image.

free

Free cached object structures and associated data. This command may be useful when memory is low and a completely different view is being generated from the one previous.

last [ file ]

Restore the previous view. If a view or picture file is specified, the parameters are taken from the last view entry in the file.

L [ vw [ rfile ] ]

Load parameters for view vw from the simulation control file rfile (known as "rad(1) input file" in standalone Radiance use, usually with the extension .rif). Both vw and rfile must be given the first call, but subsequent calls will use the last rfile as a default, and "1" as the default view (ie. the first view appearing in rfile). If rview(1) was started by rad(1), then the rfile parameter will initially default to the rad(1) input file used.
Note: Since Rayfront doesn't store view data in simulation control files, use of this command is not recommended.

move [ mag [ x y z ] ]

Move camera mag times closer to point x y z . For a perspective projection (or fisheye view), only the view point is changed; the view direction and size remain constant. The view size must be modified in a parallel projection since it determines magnification. If x y z is missing, the cursor is used to select the view center. A negative magnification factor decreases the object size. The default factor is one. Care must be taken to avoid moving behind or inside other objects.

new

Restart the image. Usually used after the "set" command.

pivot angle [ elev [ mag [ x y z ] ] ]

Similar to the "move" command, but pivots the view about a selected point. The angle is mea­ sured in degrees around the view up vector using the right hand rule. The optional elev is the elevation in degrees from the pivot point; posi­ tive raises the view point to look downward and negative lowers the view point to look upward.

quit

Quit the previewer.

^R

Redraw the image. Use when the display gets corrupted. On some displays, occassionally forcing a redraw can improve appearance, as more color information is available and the driver can make a better color table selection.

rotate angle [ elev [ mag ] ]

Rotate the camera horizontally by angle degrees. If an elevation is specified, the camera looks upward elev degrees. (Negative means look downward.)

set [ var [ val ] ]

Check/change program variable. If var is absent, the list of available variables is displayed. If val is absent, the current value of the variable is displayed and changed interactively. Otherwise, the variable var assumes the value val.
Variables include:

av		ambient value
aw		ambient value weight
ab		ambient bounces
aa		ambient accuracy
ad		ambient divisions
ar		ambient resolution
as		ambient super-samples
dc		direct certainty
dj		direct jitter
ds		direct sampling
dt		direct threshold
ps		pixel sample
pt		pixel threshold
sj		specular jitter
st		specular threshold
lw		limit ray weight
lr		limit reflections
dv		light source visibility
bv		back face visibility
b		display in black and white
i		calculate irradiance

Once a variable has been changed, the "new" command can be used to recompute the image with the new parameters.

trace [ xorig yorig zorig xdir ydir zdir ]

Trace a ray. If the ray origin and direction are absent, the cursor is used to pick a loca­ tion in the image to trace. The object inter­ sected and its material, location and value are displayed.

view [ file [ comments ] ]

Check/change view parameters. If file is pre­ sent, the view parameters are appended to a file, followed by comments if any. Alternatively, view options may be given directly on the command line instead of an output view file. Otherwise, view parameters are displayed and changed interactively.

V [ vw [ rfile ] ]

Append the current view as view vw in the rad(1) file rfile. Compliment to L command. Note that the view is simply appended to the file, and previous views with the same name should be removed before using the file with rad(1).
Note: Since Rayfront doesn't store view data in simulation control files, use of this command is not recommended.

write [ file ]

Write picture to file. If argument is missing, the current file name is used.

^Z

Stop the program. The screen will be redrawn when the program continues. On some systems, the previewer may disappear from the screen when stopped, on others it will just become unresponsive to user input.
Note: Since the previewer is started by Rayfront directly, and not by a shell, you will have to use the kill(1) program to send a CONT signal to the program for continuing. Use of this command is not recommended when the previewer is started by Rayfront.

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