Most of the light fixtures in Chaos Cosmos come with luminaire files so using them is simply a matter of drag and drop. If a light fixture doesnt have a luminaire file, it either has no light sources, or adding a luminaire does not improve the results (for example if the light sources directly illuminate the scene and there is no complex light transport). A tutorialon creating luminaire files for customlight fixtures is coming soon.Working with VRayLuminaire light sourcesIf a light fixture has a VRayLuminaire object attached to it, then control of the light emitted from the fixture, like intensity and temperature, should be handled from the VRayLuminaire object. However at this time, disabling a VRayLuminaire light simply disables the light field calculation and not the regular light sources that are a part of the light fixture. An easy way to disable all of the light emitted from the fixture is to set the intensity of the VRayLuminaire light to 0.0.Similarly, in the VRayLightMix system, the original lights in the fixture and the VRayLuminaire light will appear separately; this is something that will be improved in subsequent V-Ray 7 releases.