Access mesh height at point, post displacement

HI,

I’m trying to build some (very basic) buoyancy physics. I’ve built some water, via a world displacement material, and now I need to pass that height information to a floating object, so it can tell if it is above or below water. The problem is, I don’t know how!

My first impulse was just to do a simple ray cast to check if the object was above or below water, but unfortunately, you need collision to interact with a ray, and the collider mesh does not distort along with the material.

I found a tutorial here, but I’m pretty new to Unreal, and I couldn’t decipher the critical section.

Thanks!!