Arnold GPU - Cryptomatte masking AOV alternatives

[Intuos5]

I would like to know whether there are any other options to create masking AOVs for Arnold GPU, because currently, cryptomattes are not supported. Preferably, I would like to mask out objects for post-compositing in Photoshop. 

[Christoph_Schaedl]

create a custom ID pass.

https://www.youtube.com/watch?v=91n_YMgzKv0

You could also use this script todo so.

import maya.cmds as cmds
import mtoa.aovs as aovs

aovs.AOVInterface().addAOV("Object_ID")

UtiD = cmds.createNode("aiUtility" , name="aiUtility_ID") 
cmds.setAttr('aiUtility_ID.shadeMode' , 2)
cmds.setAttr('aiUtility_ID.colorMode' , 21)


cmds.connectAttr('aiUtility_ID.outColor' , 'aiAOV_Object_ID.defaultValue')

[Intuos5]

@Christoph_Schaedl Thank you for your quick response. 
I am sorry, but I see that the video is for Maya and the script also contains "maya.cmds" are you sure that this works in 3ds Max?