I want to use UIInterpolatingMotionEffect within SwiftUI. I was thinking to use the coordinator as a way to bridge between UIKit ans SiwftUI with no success. I want to change the amount of shadow of a rounded rectangle depending on the tilting of the iPhone. Any idea to achive this. Maybe it is possible to get the underlying UIVie for this.

I just started looking into this kind of thing today to create shimmering text based on phone tilt. I found a tool that lets you add parallax movement to any SwiftUI view which might help you out as well. It uses UIViewController and UIViewControllerRepresentable

https://github.com/Priva28/ParallaxSwiftUI

Actually, this is way easier and performs a lot better:

https://trailingclosure.com/device-motion-effect/