Allows mixed lights to control shadow caster culling when Shadowmasks are present.
| Default | Use the global Shadowmask Mode from the quality settings. | 
| NonLightmappedOnly | Render only non-lightmapped objects into the shadow map. This corresponds with the Shadowmask mode. | 
| Everything | Render all shadow casters into the shadow map. This corresponds with the distance Shadowmask mode. |