My English is good and I understood what you want and was pointing you towards a “tool” you can use in UE4 to accomplish what you want. Since you have text that is “moving”, you are animating it somehow. Perhaps you could do it with a “mask” overlaying the image and set its opacity to change vertically or horizontally although I think that would be much more work than what I will suggest to you using the UMG animator. Basically what you need is not a “transparent” that would be useless then you would see the image all the time and not even notice anything is in front of it. Glass is transparent…it hides nothing, so I doubt that is what you want. What you really want is something opaque to block all the text you want to hide. Then use the animation tool to slowly pull the “opaque wall” up, down, left or right depending on how you want to reveal your text. So the text will always be present in the center of your screen (or wherever you choose to place it) and the “opaque wall” will cover it, then you animate the wall to move away in some direction revealing the text beneath. Def can be done easily in UE4.