override material not working as it should be?

[vanderloo]

After importing a Revit file into max, I assigned a vrayMtl override material to everything and rendered, and everything was as it should be.
After saving and closing the file, and re-opening, now everything renders black. And when I click on show shaded materials in viewport they remain multi colored and selecting each object's materials gives me "autodesk generic" materials.
Why isn't the override material applying?
Thanks

[Alex_M]

It's a bit hard to tell what's wrong without posting some screenshots. By saying "vrayMtl override material" do you mean the slot in the "Global Switches" tab of Vray's render settings? If yes, then make sure that you've enabled the checkbox where it says "Override mtl". Also make sure that in the "Exclude..." list you have selected the exclude option and don't have any objects in the list to the right.

Might be also that you have forgotten to turn on your lights. Or maybe you have disabled them altogether in Vray's settings by mistake? There could be many reasons but unless we can see some screenshots it will be hard to figure it out.

[vlado]

The option for overriding the material only works at render time; it doesn't change any materials in the scene itself.

As for why it renders black, do you have any lights in the scene?

Best regards,
Vlado

[glorybound]

Happened to me before, too. Changing back to default render engine and back to V-Ray solved it for me.