How do I use an Ambient Occlusion map with the Principled Shader? There are fields to use PBR maps for Base Color, Normal map, etc, but I don't see one for AO. Or is there a way to multiply the AO map with he Base Color map? If so, how?

I have tried using a Layer Mix node but this blends the maps making the Base Color map less saturated, so it is not the way.

You don't use an ao map with a photorealistic material. The lighting is calculated using path tracing.

There is a "passthrough" slot on some baking materials that tell the exporter which map will be the ao map on export. The principled material might not have this passthrough slot.

I have a reason for using the AO map. It is often used in game engines. In Maya, for example, you can directly feed it in to the material.

litote
I have a reason for using the AO map. It is often used in game engines. In Maya, for example, you can directly feed it in to the material.

If a developer hires a professional to demonstrate a new tool, then the editor is popularized, especially if it is done for all new tools, - apparently the developers already earn a lot from selling Houdini - they don't need to work harder.

For example the developers of 3d-coat editor hired only one professional to work on the forum - as a result all questions on the forum have a professional answer. This and many other things have not been realized here.

you can use Texture VOP to get your Diffuse and AO textures, multiply them and plug into Basecolor input of Principled Shader

Thanks Thomas,

Does this look correct?:

https://ibb.co/gtn1WPQ [ibb.co]

It seems to render correctly but it does not show in the viewport - is this normal, or should it also show in the viewport? I have v18.5 on a Mac with an inadequate GPU.

tamte
you can use Texture VOP to get your Diffuse and AO textures, mult

"From Wikipedia, the free encyclopedia

The ambient occlusion map (middle image) for this scene darkens only the innermost angles of corners.
In 3D computer graphics, modeling, and animation, ambient occlusion is a shading and rendering technique used to calculate how exposed each point in a scene is to ambient lighting. For example, the interior of a tube is typically more occluded (and hence darker) than the exposed outer surfaces, and becomes darker the deeper inside the tube one goes."

In some cases the ambient occlusion is dirt, but sometimes it is a "small" shadow.
When I direct light to the surface, the ambient occlusion should disappear because it was a shadow.
If I use your method, the ambient occlusion will be integrated into the texture and will not disappear

Fordencore1966
If I use your method, the ambient occlusion will be integrated into the texture and will not disappear

We are talking about using baked AO map which games use sometimes, so I believe if you have such map its meant to be multiplied with diffuse, but you are free to use it however you want to mimic how it was intended to be used by author of such map


Otherwise there is no place for traditional AO in the shader since that technique used to fake ambient occlusion lighting which is taken care of by Dome Light nowadays