selling models when using vray render

this reason why mentioned rthis i spend hour using environemnt kmap to get my metal right in vray 3ds max. Th custome then my use model in obj blendere maya . the rmodels the same its never changed they will get different results.

I know theres pbr , i dont see pbr exporting that well vray 3ds max

If you're selling one or more objects with Multi-Subobject materials, you can offer multiple material views for different render engines using the Slate Material Editor. For example, you could offer a model with Vray materials by default, but then also create a different material view for other render engines. Users can quickly replace the Vray materials with Corona, Standard, or whatever engine you are capable of offering if they have that engine. It's a little bit more work, but buyers might appreciate the effort if you mention this in your sale description.

Technically speaking, V-Ray is a plugin and its usage should be marked, but if you provide more file formats and especially native file with materials for native renderer, then i think it's not neccessary to check "plugins used" checkbox. This is my opinion only and others may not agree with that. In any case, it's always safer to notify customer about all plugins that was used and/or required to reproduce preview renders.

yes!