Green Screen Chroma Key to Transparent

Bobakanoosh wrote on 10/11/2018, 7:47 PM

Hey,

I'm trying to make a twitch follow/sub alert that appears on screen and plays a short video/gif. I have my video recorded on a green screen and I've adjusted the Chroma Key to my liking, but it just turns it to a black background. I cannot find anything anywhere, how do I make the background of my video to be transparent so I can overlay it on stream?

Thanks!

Comments

Musicvid wrote on 10/11/2018, 8:21 PM

We'll, you would use source alpha, and put your generated track above.

Bobakanoosh wrote on 10/11/2018, 8:33 PM

We'll, you would use source alpha, and put your generated track above.

What do you mean "Use source alpha"?

Former user wrote on 10/11/2018, 9:12 PM

You have to have at least two video tracks. Your chroma key will reveal what is in the lower track. If it is black, it will show black.

EricLNZ wrote on 10/11/2018, 10:17 PM

Are you trying to export it as a file with a transparent background?

Musicvid wrote on 10/11/2018, 10:28 PM

Source Alpha is one of the basic Compositing Modes on your Video Tracks. Search this forum, the tutorials, and the internet for instructions. Read and learn, and good luck.

karma17 wrote on 10/12/2018, 4:11 AM

This video talks a little about the alpha channel adjustment, which would be under the Channel Blend fx.

If your screen is properly keyed, the background will appear black, but that blackness should be transparent to the layers beneath it.

If the background is black and that blackness doesn't go away, then your alpha channel (the one that controls transparency) needs to be turned down using Channel Blend as shown in the video.

Also, you might find this video instructive:

http://tale2tell.com/sony-vegas-pro-44-composition-modes/

It can get confusing because depending on the compositing mode you're in, black can also be opaque and not necessarily related to the alpha channel so much as it is the compositing mode you're in.

 

 

 

 

 

 

Bobakanoosh wrote on 10/12/2018, 11:29 AM

Are you trying to export it as a file with a transparent background?

Correct. I want to overlay the video on my live stream, not on another video in sony vegas. Turning it into a gif w/ transparent background would be even better.

I will try the other things posted here later today

EricLNZ wrote on 10/12/2018, 5:02 PM

Are you trying to export it as a file with a transparent background?

Correct. I want to overlay the video on my live stream, not on another video in sony vegas. Turning it into a gif w/ transparent background would be even better.

I will try the other things posted here later today

You need to export as a file format that supports transparency. To my limited knowledge that means it needs to be a mov file using a codec that supports transparency. Now we've established what you are trying to do I'll leave it to more experienced forum members help you achieve it.