Trouble understanding copy stamping

I’m having trouble understanding copy stamping, specifically as it relates to expressions. I am trying to have each instance of a copy reference a chop to determine it’s scale in Y. but i dont understand why the expression i wrote works perfectly in an evaluate DAT but won’t execute in the SOP. i guess it might have to do with not understanding the second argument in the function that references the copy index? i’ve shared an example.
plane with noise and intersecting points.toe (7.06 KB)

Looks like transform3 was in tscript mode instead of python mode.

Once its in python mode, change the expression to:


That should get you further.