Animating a cylinder to open

Could anyone offer suggestions about how to animate a cylinder opening in Unreal? CylinderOpen.jpg

I’d probably cheat with a high-rez cube as part of a splinemesh component and animate one end following a circle spline. Radius of the circle spline should match the cubes halfwidth.

Or could be clever with scrubbing masked opacity in the cyllinder’s material and animating 2 planes to make the inside of the pacman