This page provides information on V-Ray compatibility with 3ds Max texture baking.
Overview
V-Ray provides support for the texture baking mode of 3ds Max. You can use V-Ray as a texture-baking renderer.
However, since V-Ray does not support the standard 3ds Max Render Elements, you need to use the V-Ray specific ones (e.g. VRayCompleteMap instead of CompleteMap, etc.). A full list of the V-Ray output elements (bake elements) and how to access them can be found at the Bake Elements page.