**bset_align

Description

This command aligns lisets (in 2D) and fasets (in 3D) such that their “normals” are aligned in the same direction sign-wise. The normals are still normal to the face.

The bset normal alignment is very important for certain boundary conditions (e.g. pressure) and contact surfaces to be correctly defined.

Syntax

**bset_align \(~\,\) *bsets bset1  …  bsetN [ *normal (direction) ] [ *towards (point) ] [ *away_from (point) ] [ *inwards ] [ *tolerance tol ]

By default (i.e. if neither normal, towards nor away_from are specified), the bset are oriented outwards (or inwards, if it is specified).

*bsets

is the list of bsets on which the reorientation is applied. The shorthand ALL may be used to select all bsets.

*normal

is a global direction that all normals will be aligned with (positive scalar product)

*towards

all normals will be directed towards this point

*away_from

all normals will be directed away from this point

*inwards

all normals will be directed inwards (instead of the default outwards)

These last 4 options are of course mutually exclusive. Note that the vectors must be entered using vector notation (see conventions).

*tolerance

The minimum projection tolerance below which the direction is considered to be included in the plane of the bset (if applicable, arbitrary choice of the normal).

Note

This mesher replaces **faset_align, which was only available in 3D.

Example

**bset_align
 *bsets  top  bottom
 *normal (0. -1. 0.)   % all normals will point down

**bset_align
 *bsets exterior       % all normals will point outwards

**bset_align
 *bsets left right
 *towards (0. 0. 0.)   % all normals will point to the origin