How to render Alpha background in unreal either using matinee or sequencer?

Cr1s1s

Sorry if this has been asked before, I plan to make turntable for some of the assets in the Unreal engine 4.13, but i am required to have alpha backgrounds for the assets. I have done some research and tried a few methods that i found online but didn't get them to work completely. Anyone here would know an optimal way to get around rendering an alpha background in unreal or any kind of trick which could work? i have black backgrounds with my assets currently. 

Obscura

I don't know the way with sequencer, but one easy way would be to make a post process that outputs the opacity pass. And then you just apply that PP on the camera and you render with that. Then you disable the PP and render once more without it. This should work with both sequencer and matinee, but there might be a batter way though... Or if you mean a transparent background, then try saving as png.

Cr1s1s

Yeah i did mean a transparent background, since i am required to not have the black background , at the same time i am not supposed to have any colored walls, so pretty much a transparent background.

Obscura

png.

nicknameminivan

Try this for Alpha Channel maybe?

https://www.youtube.com/watch?v=pWBQFat70HU