Function simplify 

pub fn simplify(
    tx: &mut Transaction<'_>,
    options: &SimplifyOptions,
) -> Result<SimplifyReport>

Shrinks the mesh toward options.target_triangles by quadric-error edge collapses (see the module docs). Boundary vertices stay put when preserve_boundary is set. Stops early when no valid collapse is left, which can leave more triangles than the target on meshes with locked or non-manifold edges.

A target at or above the live count, and an empty mesh, succeed without writing. Otherwise at least one collapse runs and the patch is non-empty.

Errors

OpsError::InvalidInput for a zero target; OpsError::Store when memory runs out.