Question / Help How to only key green screen and not green game pieces

[PinupGamer]

Hello All,

I am new to all of this so please be gentle. :)

My co-host and I stream board games live on Twitch and YouTube simultaneously using OBS. We stream playing board games so we have game pieces visible in our opening and closing scenes. Our overhead camera scene shows the game as we are playing it, but this scene is unaffected. We would like to incorporate the use of green a green screen for our opening and closing scenes. I have used green screens for edited video so I am familiar with the key feature in Adobe Premiere, most notable the garbage matte. Is this a feature available in OBS? Can I isolate parts of a scene that contain green components so that it doesn't key with the green screen?

Any help would be appreciated. Thank you.

 

[MudBocx]

Is his a feature available in OBS? Can I isolate parts of a scene that contain green components so that it doesn't key with the green screen?

G'Day,
you do have matte masking functionalities in OBS. You can use a combo of black-white mattes to isolate certain areas and leave others unaffected. However you need to rely only on premade mattes - no vectors etc.

From a production standpoint alone I'd recommend preproducing intro/outro or mid-roll sequences. If you don't have a person for live editing, this is the smarter thing to do. Otherwise you are opening a can of worms revealing a multitude of other possible problems - believe me you probably don't want that :)

 

[koala]

You can use the Image Mask/Blend filter to remove parts of the video, and you have the Color Key filter to apply the green screen effect to the whole source. As far as I know, you can apply the color key filter only to a source as a whole, not to only a masked part of it.

This could probably work:
Extract the part you don't want to be green-screened and put it on top of the green-screened version of the same source, so it overlays the green-screened part.

Perhaps this way:
- create a mask for the part of your source you don't want to green-screened
- duplicate your source, so it is listed twice (use copy and paste (reference))
- create a group and move your first source into it (group 1 -> on top)
- create a second group and move your second source into it (group 2, and put it below group 1)

Now you have 2 groups with a reference to the same source in it. The purpose of the groups is the filtering. To add filters that apply to one instance but not the other, add the filter to the group the source is in, not to the source itself. Filters are global to a source, so if you need one copy with a filter and another copy without the filter, you have to do this with groups.
Continue:
- deactivate group 1, so it is invisible
- to group 2, add the color key filter to apply your green screen effect.
- deactivate group 2, so it is invisible, and activate group 1
- to group 1, add the Image Mask/Blend filter and configure the mask you created. You should now only see the stuff you want to be not green-screened. The rest of the source should be transparent due to the mask.
- activate the group 2.
Now, the green-screened frames are drawn below the partial (masked) frames that are not green-screened. You overwrite the parts from group 2 you don't want to be green-screened with group 1. Ordering of the groups is important.

 

[PinupGamer]

Thanks everyone for your help!

@koala This is very similar to when I use garbage mattes in Adobe Premiere. I will try your suggestions this week in our test run!