Idea requested: how to implement the spatial collapse effect?

I’m curious in Unreal 4 how to perform the visual effect as if the space is collapsed towards the center as in the following figure. I’d like this effect to take place at a certain location with a certain radius.

139832-spatial_collapse_example.png

What I’ve achieved is pretty far from it: apply post-processing material where the uv of any point in the circle is replaced by a point on the circle, shown in the following figure, which looks ugly.

139833-simple_try.png

Any suggestion is much appreciated !

SOLVED: Recycler grenade in Prey (2017), open source [Unreal engine 4] - YouTube