rtscale — supplements rthide output by plotting a scale to indicate drawing size in arbitrary units.
rtscale supplements the use of rthide by generating a UNIX-Plot of a scale that permits the accurate measuring of rthide plots. rthide provides a hidden-line-removed plot of the geometry, and rtscale produces an identical plot file containing just a scale. The two files can then be concatenated making sure that the scale precedes the rthide file to produce a finished plot with scale.
Rtscale operates on the RT log file from the rthide run and produces a UNIX-Plot file of a scale with desired units and number of tick marks. The scale's width is given in model units. A descriptive string may be added. The scale and the strings are plotted in the lower left corner of the image.
The inputs required are: width, which specifies the length of the scale in model space, units, which may be any units (metric or English), intervals, which allows the user to specifies the number of tickmarks on the scale. filename, which names the RT log file that is used to calculate the view2model matrix for the raytraced. A view such as azimuth 45, elevation 45, is useful for measuring diagonal dimensions of the geometry. Optionally, a descriptive string may be given to identify the view or the model.
This section shows the ordinary usage of rtscale. For example:
rtscale 30 mm 10 rt.log > scale.plot3
This will result in a 30 mm scale with ten tickmarks being plotted in the lower left corner of the scale.plot3 image. Alternately, a descriptive string may be given to identify the view or the model:
rtscale 30 mm 10 rt.log "UH-60 a90 e0" > scale.plot3
Note that a descriptive string longer than 28 characters will be cut off by plot3-fb.
The plot file is now concatenated with the plot file of the image to scale needs to be put on. The order in which they are concatenated is important: the scale is always concatenated over top of the model plot:
cat scale.plot3 model.plot3 >> model.w.scale.plot3
The resulting UNIX-Plot of the geometry with a scale added to it can be viewed in several ways. It can be overlaid in mged, or it can be rotated to the desired azimuth and elevation with plot3rot and be stored in a file or view with plot3-fb:
plot3rot -a# -e# -g model.w.scale.plot3 | plot3-fb
Numerous error conditions are possible, usually due to errors in the geometry database. Descriptive messages are printed on standard error (file descriptor 2).