AO map to which channel in vray material?

[mhouse777]

Hi,
I made an AO map in another program and want to add it it to the vray material in 3ds max 2019. Just wondering which channel to attach it....see attached. Thanks

[dgruwier]

There's no predefined slot for it to go into in VRay, but multiplying it with the diffuse map should do it.

[mhouse777]

Thanks dgruwier,
I'm new to all this, I dont know what multiplying is and how to do it. Is it combining the diffuse map with the AO map through another map and then into the material?

[^Lele^]

Yes, you can use the vraycomptex, plugging one map in each slot, and choosing multiply for the operation.

[mhouse777]

Very helpful, Thanks LeLe.

[Ihno]

AO isn't really needed for a raytracer like vray, ao is an unrealistic attempt to mimic gi. It was a cheat in the past to spice up blurry gi solutions and its still used in game engines. But now days, for vray it's better(more realistic) to not use it.

[dgruwier]

It's true that ideally you would not need AO in your materials, but it's also not completely cut and dry. If you're stuck with a material that only comes with a bump/normal map and no height map for displacement, careful use of the included AO map can still be helpful to add detail that would otherwise be missing.
But yeah, if you have a material with proper displacement, then VRay can do real global illumination, and that's the better option.