Normalise object space Arnold shading network

[MrEddie]

Hi there, I am researching workflows to:

Normalise ambient occlusion on a shader to work on multiple objects and sort of look the same at different scales. I believe this is easy to do in blender.

I can do it with aiuserdata nodes and variables on each mesh, or Maya’s single switch per object, or with an expression. I would read the bounding box first per object to find a suitable value for ‘.farclip’ for each object.

All feels a little over complicated… Is there anything built in to do the automatically? I feel like I am missing something simple or that an arnold node exists that does the calculation?

[Radwan-Almsora]

Normalizing Ambient Occlusion (AO) across multiple objects of different scales without relying on manual expressions or bounding box calculations is easily handled in Arnold using the built-in State or Ray Switch nodes, which dynamically capture object data at render time.

To resolve your issue, you can enter here. 

Utility - Arnold User Guide

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[MrEddie]

Great thanks for that.

I wonder if you have time, that we could see a screen shot of an example network (multiple objects of different world space scales, that the network adjusts the relevant attributes per case) ? 
Would really appreciate it to see your workflow?

[MrEddie · Accepted solution]

So I think I found the solution. 

aiSpaceTransform, is the solution. Transforming from object to world space. The farclip is calculated based on the scale of the objects. 

Working well. Wish it was better documented!