In this (Overview/Demo) video, I will talk about using external/hardware keyers with Unreal Engine for Green Screen keying. I will cover the concept of Matte and Fill outputs. I will also cover Blackmagic's Ultimatte HD Mini, HD and 4K versions as well as their advantages and shortcomings. Lastly I will also cover Aximmetry's keyer. This is part 1 (overview/demo) of a 2 part video. The second part will cover in detail how to set up and operate them. This is a video I wish I had when I was first starting so I believe you will learn lots from it. Chapters: 0:00-0:42 -Intro 0:43-1:00 -All Ultimatte Models 1:01-2:21 -Ultimatte Mini HD 2:22-3:24 -What is Fill and Matte 3:25-6:41 -Demo Using Ultimatte HD Mini 6:42-7:49 -Ultimatte Mini plus Fill and Matte 7:50-9:00 -Ultimatte 4K 9:01-10:42 -Aximmetry