# Irregular Polyhedron Automatic Meshing

You may define an orthogonal frame (`O`,
`V`_{1},
`V`_{2}, and
`V`_{3}), a bounding-box of the
airbag fabric to be mesh defined by the lengths
(`L`_{1},
`L`_{2}, and
`L`_{3}) and the number of
cutting-step for each direction
(`N`_{1},
`N`_{2}, and
`N`_{3}).

The cutting width is then given by:(1)

$${W}_{i}=\frac{2{L}_{i}}{{N}_{i}}$$

Figure 1 shows a two-dimensional case of how
the airbag fabric is cut:

The automatic meshing procedure is also required if the set of user-defined solids
(

`Ibric`) does not entirely fill the internal volume of the airbag.For example, in a case of a folded airbag with a right choice for the cutting
direction V1 and V2, meshing may be sufficient:

In cases where the injector is modeled with an initial rigid volume (canister), using
only two cutting direction (V1 and V3) gives a coarser mesh.

In this example, it may be greater to use the third cutting direction (V2) to reach
the following mesh: