This is a follow up post to the Quick Ambient Occlusion Pass Creation in 3ds Max and VRay article. In that article we discussed how you could use a nifty plugin for getting quick AO passes. If you haven’t checked it out yet, you should do so now. With the help of the plugin you can create your AO passes with a single click.

So the purpose of this tutorial is to teach you a manual way of getting the same result. If you’re somehow unable to use the AO plugin, this simple trick will let you render an AO pass using VRay alone.

Manual Ambient Occlusion Pass

To render out the AO pass without the help of the plugin, follow these steps:

1. Create a new VRay Light Material. This will act as the white portion in our AO layer. The light material will not be affected by the scene lights and therefore no unnecessary shadows.
2. Add a new VRay Dirt Map in the color slot of the VRay Light material. The dirt map is essentially an ambient occlusion calculator.
3. Add a radius of 200 and a falloff of 5 for the dirt map. This helps in getting a smooth and soft AO calculation.
4. Apply this VRay Light Material to the Override Mtl. slot in Global Switches rollout of VRay settings.
5. Hide your glass objects in the scene before hitting that render button.

By changing the radius parameter of the Dirt Map, you can control the softness of the AO pass. If you found this tip helpful, then subscribe to this blog for more VRay centric tutorials. Don’t forget to share and comment below.