G-SHELL.RECT(1)

NAME
g-shell.rect - Produce triangulated shell from BRL-CAD model

SYNOPSIS
g-shell.rect [-d debug_level] [-n] [-g cell_size] [-i initial_ray_dir] [-d debug_level] -o brlcad_output_file database.g object(s)

DESCRIPTION
g-shell.rect converts the specified objects(s) from a BRL-CAD model database.g to a single NMG solid using raytracing. Rays are fired in a uniform grid with spacing specified in millimeters using the -g option (default is 50mm). The -d option requests debug information and produces more extensive messages as the debug_level increases. The direction for the first set of rays is chosen by calculating the presented area of the bounding box of the object(s) and selecting the direction with the largest area. The user may override this by specifying a desired initial ray direction using the -i option. The ray direction must be spcified as X, Y, or Z. The best results are usually obtained by raytracing in the direction that produces the most hits first. The initial shell is constructed using only the first and last intersections with the object(s). This will typically result in some rather large faces with normals at right angles to the ray direction. These faces are then subdivided (according to the cell_size ) and additional rays fired from the other two directions are used to refine their shape. The -n option requests that this additional refinement not be done. The resulting NMG solid will be named shell and will be written to the specified brlcad_output_file.

EXAMPLE
    $ g-shell.rect -o shell.g sample.g sample_object

DIAGNOSTICS
Error messages are intended to be self-explanatory.

AUTHOR
John Anderson

SOURCE
SLAD/BVLD/VMB Advanced Computer Systems Team
The U. S. Army Research Laboratory
Aberdeen Proving Ground, MD 21005

BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to <CAD@ARL.ARMY.MIL>.