GLINT(1)

NAME

glint - sample BRL-CAD geometry for overlaps and air problems

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SYNOPSIS
DESCRIPTION
OPTIONS
EXAMPLES
SEE ALSO
AUTHOR
COPYRIGHT
BUG REPORTS

SYNOPSIS

glint [-copsu] [-a _az_] [-e _el_] [-g _gridsize_] [-r _bits_] [-t _tol_] [-x _bits_] _model.g_ _object_...

glint uses librt(3) to fire a regular grid of parallel rays at the specified object(s) in the database model.g and reports overlaps, vacuums (voids), and potential problems with modeled air regions.

By default the output is one single-line ASCII report per problem. Each report begins with a tag identifying its type, followed by the relevant data. The report formats are:

overlap r1 r2 length x_in y_in z_in x_out y_out z_out: Consecutive partitions overlap by more than tol. Reports the names of the two regions, the overlap length along the ray, and the model coordinates of the ray’s entry and exit points.
air_contiguous r1 a1 r2 a2 x y z: Consecutive partitions have different (non-zero) air codes, and the gap between them is less than tol. Reports the names and air codes of the two regions and the point coordinates.
air_unconfined r1 (s1) r2 (s2) length x1 y1 z1 x2 y2 z2: A partition with a non-zero air code abuts another partition across a gap larger than tol. Reports the names of the regions (and solids) involved, the gap length, and coordinates.
air_first r a x y z: The first partition along a ray has a non-zero air code. Reports the region name, its air code, and the ray entry coordinates.
air_last r a x y z: The last partition along a ray has a non-zero air code. Reports the region name, its air code, and the ray exit coordinates.
vacuum r1 (s1) r2 (s2) length x1 y1 z1 x2 y2 z2: The space between consecutive partitions is larger than tol. Reports the regions (and solids) involved, the gap length, and the coordinates.

When the ray origin is requested (-o) the model coordinates of the ray’s origination point are inserted between the report tag and the remaining data. When plot3 output is requested (-p) the problems are emitted as colored plot3(5) geometry instead of text.

OPTIONS

-a az: Set the azimuth angle from which to fire rays. The default is 0.
-c: Fire one ray from the exact center of each grid cell. By default rays are fired from a random point within each cell.
-e el: Set the elevation angle from which to fire rays, in the range -90 to 90. The default is 0.
-g gridsize: Set the width and height of each grid cell, in millimeters. The default is 100.
-o: Include the model coordinates of the ray’s origination point in each report.
-p: Produce output in plot3(5) format rather than ASCII text, useful for overlaying results in mged(1).
-r bits: Select which report types to produce using a bitmask (decimal, octal with a leading 0, or hex with a leading 0x). Prefixing the value with a minus sign negates the selection (specifies what NOT to report). The bit values are 1 (overlaps), 2 (contiguous unlike airs), 4 (unconfined airs), 8 (air first on rays), 16 (air last on rays), and 32 (vacuums). The default is 1 (overlaps only).
-s: Collect and sort overlap reports before printing, grouping them by region pair in order of decreasing cumulative overlap length. By default overlaps are reported immediately as they are found. This overrides -p.
-t tol: Set the length tolerance, in millimeters, below which overlaps, vacuums, and air gaps are ignored. The default is 0.
-u: Enable reporting on partitions containing air. This is set implicitly whenever an air-related report bit is requested via -r.
-x bits: Set glint diagnostic flags. The value is interpreted as hexadecimal.
-h
-?: Print the usage message and exit.

EXAMPLES

Example 1. Find overlaps with a fine grid and a tolerance

glint -c -g 1.0 -t 0.01 vehicle.g hull

Fires one ray per 1mm grid cell from the center of each cell at the hull combination in vehicle.g, reporting only overlaps longer than 0.01mm. A fine grid catches small interferences that a coarse grid would step over.

Example 2. Audit air regions and visualize the results in MGED

glint -r 62 -p cabin.g interior > air.plot3

Selects every report type except plain overlaps (62 = 2+4+8+16+32) and emits plot3(5) geometry, which can be overlaid on the model with the overlay command in mged(1) to see exactly where the air problems occur.