Caustics

As the wormhole neck is of finite size, we would not expect caustics to develop, at least within the vicinity of the neck.

Caustics are bright patterns caused by the focusing of light off a wide reflective region onto a narrow area of (near-)diffuse surface.

Here one should remind to the well-known fact that the important "quasi-optical" singularities of the so-called eikonal approximations of many wave-equations, namely the " caustics ", are resolved into finite peaks beyond that approximation.

In practice, however, only the simulation of diffuse inter-reflection or caustics is called global illumination.