This example shows how to set up the indirectlight object for caustic photon map generation and also how light masks and photon targets should be used. The scene consists of a reflective tube and a point and environment light. Each light has a corresponding indirectlight to generate caustics, with the light mask configured to allow the light to generate photons only from the specified light. The photon target is used to ensure that photons are only sent toward the reflective tube. The mantra ROP will produce deep raster planes for the direct_diffuse component on a per-light basis, showing the diffuse illumination from the two lights and the caustics split into separate planes.