topology.borders (procNode)

For every edge of the geometry's edge table (core.edges), how many of the faces that take part border it: 1 is an open edge of the participating faces, 2 a shared one, 0 an edge none of them touches. The faces taking part are all of them when no group is named. What topology.edges and topology.boundary read their open edges from.

Inputs

• geometry (Geometry): the geometry whose edges are measured.
• group (String, default ""): names a 0/1 attribute on class restricting which faces take part; empty, the whole mesh takes part. A name the class does not carry is refused.
• class (String, default "primitive"): the class group lives on: "edge", "point", "primitive" or "vertex".
• promote (String, default "all"): how a group on a class other than "primitive" becomes a face set: "all" takes the faces every one of whose elements of that class is in the group, "any" the faces at least one is.

Outputs

• borders (Field<Float>): per edge of the core.edges table, in its order, the number of participating faces that border it.

Example

local borders = g.topology.borders({ geometry = g.mesh.grid({}) })