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RTSCALE(1)

NAME

rtscale - plot a measuring scale for an rt/rthide UNIX-Plot image

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SYNOPSIS

rtscale _width_ _units_ _intervals_ _file.log_ [_string_] > scale.plot3

DESCRIPTION

rtscale generates a UNIX-Plot (see plot3(5)) of a labeled measuring scale that can be overlaid onto a raytraced image to allow accurate measurement of geometry. It is most often paired with rthide(1): rthide produces a hidden-line plot of the geometry, and rtscale produces a matching plot containing only a scale. Concatenating the two files, with the scale first, yields a finished plot complete with a scale.

rtscale reads the RT log file written by the rt(1)-family run and uses the view, orientation, eye position, and size recorded there to build the view-to-model matrix. The scale is laid out in view coordinates, drawn as a line with tick marks ending on a "nice" rounded value, and placed in the lower left corner of the image. An optional descriptive string is drawn beneath the scale to identify the view or model.

The positional arguments are:

width

length of the scale expressed in units.

units

unit name passed to bu_units_conversion; any metric or English unit is accepted (for example mm, cm, m, in, ft).

intervals

number of tick-mark intervals along the scale.

file.log

RT log file from which the view2model matrix is computed.

string

optional descriptive label drawn under the scale.

EXAMPLES

Example 1. Scale a hidden-line rendering and view it
rthide -o model.plot3 model.g component 2> rt.log
rtscale 30 mm 10 rt.log "UH-60 a90 e0" > scale.plot3
cat scale.plot3 model.plot3 > model.w.scale.plot3
plot3rot -a35 -e25 -g model.w.scale.plot3 | plot3-fb

rthide renders the geometry and records the view in rt.log. rtscale then emits a 30 mm scale with ten intervals and a descriptive label. The scale must be concatenated ahead of the model plot so it survives rotation; plot3rot(1) reorients the combined plot and plot3-fb(1) displays it on a framebuffer. Descriptive strings longer than 28 characters are truncated by plot3-fb(1).

SEE ALSO

brlcad(1), mged(1), plot3rot(1), plot3-fb(1), rt(1), rthide(1), librt(3), libbv(3), plot3(5), ray(5V)

DIAGNOSTICS

Numerous error conditions are possible, usually due to errors in the geometry database or RT log file. Descriptive messages are printed on standard error.

AUTHOR

BRL-CAD Team

This software is Copyright (c) 1991-2026 by the United States Government as represented by U.S. Army Research Laboratory.

BUG REPORTS

Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org