ChromaKey Loses Black Color


I have some issues during experimenting with the newest UE 4.21 with BlackMagic IO support.

In my project I’m receiving simple video signal with a person on the green screen and trying to use the build-in chroma key. So here are my questions:

  1. Why the keyer drops black color? What type of compression or something should I use to avoid effect like this:

  1. The next question is about receiving key (cut) and fill from ex. hardware extender. How to blend them in the correct way? Using masked and unlit material causes a bad blending with background (for example starter content’s ceramic tile).