The c command creates a BRL-CAD combination with the name combination_name. The -r option indicates that the combination is a BRL-CAD region. The -c option is the default and indicates that the combination is not a region. The Boolean_expression allows parentheses. Where no order is specified, intersections are performed before subtractions or unions; then subtractions and unions are performed, left to right. Where there is no Boolean_expression and combination_name, a new empty combination will be created. If no Boolean_expression is provided, and combination_name does already exist and one of -c or -r is specified, then combination_name is flagged to agree with the indicated option. If a new region is created or an existing combination is flagged as a region with this command, its region-specific attributes will be set according to the current defaults (see regdef). The comb and r commands may also be used to create combinations.
The example shows how to use the c command to create a combination according to a given formula.
Example 1. Creating a combination according to a formula.
mged> c -c abc (a u b)-(a + d)Creates a combination named abc according to the formula (a u b) - (a + d).
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