TOL nged BRL-CAD BRL-CAD MGED Commands
tol Used with no arguments, `tol` lists the current tolerance settings.
`tol` abs# rel# norm# dist# perp#

## DESCRIPTION

The `tol` command, with no arguments, lists the current tolerance settings. If the command line includes any of the keywords followed by a number, then that tolerance setting will be modified. The keywords are as follows:

Tessellation tolerances: The tessellation tolerances are used to control the facetization of primitive shapes. If more than one tolerance value is specified, the tessellation is performed to meet the most stringent.

- abs -- This absolute tolerance is specified in model units and represents the maximum allowable error in the distance from the actual shape surface to the tessellated surface. An absolute tolerance of 0 means that the absolute tolerance should be ignored.

- rel -- This relative tolerance is specified in terms of a fraction of the shape size. The value is multiplied by the size of the shape to determine another bound on the maximum allowable error in the distance from the actual shape surface to the tessellated surface. A relative tolerance of 0 means that the relative tolerance should be ignored.

- norm -- This normal tolerance is specified in degrees and represents the maximum angle between the actual shape surface normal and the tessellated surface normal. A normal tolerance of 0 means that the normal tolerance should be ignored.

Calculational tolerances: The calculational tolerances are used in evaluating the Boolean operations specified in a combination. This is used, for example, in the `ev, facetize,` and `bev` commands.

- dist -- The distance tolerance is specified in model units and represents the minimum distance required between two vertices to consider them distinct.

- perp -- The perpendicularity tolerance is specified as the cosine of an angle. Two objects will be considered perpendicular if the cosine of the angle between them is less than the perpendicularity tolerance. Similarly, two objects will be considered parallel if the cosine of the angle between them is greater than 1.0, the perpendicularity tolerance.

## EXAMPLES

The example shows the use of the `tol` command to set the relative and perpendicularity tolerances.

Set the relative and perpendicularity tolerances.

mged> `tol rel .05 perp 1e-6`

Sets the relative tolerance to 5% and the perpendicularity tolerance to 1e-06 (cosine of 89.9999°).

## AUTHOR

BRL-CAD Team

## BUG REPORTS

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