Function generate_rim 

pub fn generate_rim(
    inner_mesh: &Mesh,
    vertex_offset: usize,
) -> (Vec<[u32; 3]>, usize)

Generate rim faces to connect inner and outer surfaces at boundaries.

This is the simple API that generates rims for all boundary loops.

Arguments

• inner_mesh - The inner surface mesh
• vertex_offset - Offset to add to vertex indices for the outer surface (typically equal to the number of vertices in the inner mesh)

Returns

A tuple of (rim faces, total boundary edge count).