Use this node setup, setting up AO in principled is the same as any other node.

The AO in this node setup basically does two things:-

1. Determines the colour of the AO. As you can see the color of the AO is plugged into the Mix RGB node. I additionally added a color ramp to intensify the AO effect.

2. Determines the distribution. In this node setup the Alpha of the AO is used to determine the distribution, as the AO is being Overlayed on the diffuse texture. Similarly, you can use the AO texture to control the distribution of other additional shaders or just use it directly.

Blendfile:-

Use this node setup, setting up AO in principled is the same as any other node.

The AO in this node setup basically does two things:-

1. Determines the colour of the AO. As you can see the color of the AO is plugged into the Mix RGB node. I additionally added a color ramp to intensify the AO effect.

2. Determines the distribution. In this node setup the Alpha of the AO is used to determine the distribution, as the AO is being Overlayed on the diffuse texture. Similarly, you can use the AO texture to control the distribution of other additional shaders or just use it directly.

Blendfile:-

Use this node setup, setting up AO in principled is the same as any other node.

Blendfile:-

Use this node setup, setting up AO in principled is the same as any other node.

The AO in this node setup basically does two things:-

1. Determines the colour of the AO. As you can see the color of the AO is plugged into the Mix RGB node. I additionally added a color ramp to intensify the AO effect.

2. Determines the distribution. In this node setup the Alpha of the AO is used to determine the distribution, as the AO is being Overlayed on the diffuse texture. Similarly, you can use the AO texture to control the distribution of other additional shaders or just use it directly.

Blendfile:-