Hello my dear friend, looking at your scene it seems like something complex to solve in vray and it would seem that even though you apply a material, it comes out dark black and that is only because the properties of the object in vray are activated matte shadows options as I explain in the tables that I put below and after that everything is resolved. I also send you the corrected file
Look, friend, that when you finish correcting the teapot in question due to an erroneous activation of the matte shadow, an error is generated in the swirl and illumination of the material of the teapot on the far right and it is because an incompatible material has been added to vray which generates a ´problema what I detail at the end with two images of how to change the material and solve this impasse. About lighting approaches use of the physical camera I do not explain them here since I only focus on the topic you presented, I could with a good workflow in lighting approach make shorter rendering times instead of two lights for example lighting with a dome and the help of a procedural vray bitmap and inside a hdri map which would make your scene come out much more realistic and with depth .. but that's another issue ... I hope I have helped you with my answer .. greetings!