This is as far as I've been able to get:
![Image](https://i.imgur.com/yWPj4mv.jpg)
![Image](https://i.imgur.com/6imo3s2.jpg)
It does apply a top to bottom gradient, but the colours can end up slightly skewed depending on the object it's on because of the way it's being masked and the gradient maintains its orientation instead of staying top-to-bottom even if the object spins.
I found an example of a graph that has it working in Unreal, but I'm not sure how to translate it into Amplify
https://answers.unrealengine.com/questi ... d-uvw.html