Trying to pull a key

Hello everyone,

I have a small section of some footage that I have roto’ed and I’m looking to pull a key. I’m using zMatte to try to pull the key. I have it hooked up to my background footage but nothing is happening when I adjust the sliders. I have tried different modes and nothing changes. Not sure what I’m doing wrong.

Any help would be greatly appreciated.


@ci21vfx The footage you want to pull a key from should be hooked into the Foreground input (first input on the left) while the Background input (second input from left) is used for the image you composited the keyed footage over. Check out the zMatte tutorial in the user guide for more information. It covers all the available options.

Sorry for the confusion Marco but I have a hand that is dropping dirt and I have to paint the talent out behind him.

I have drawn a shape around the hand that I want to key (roto node) and then I attached the zMatte to the footage.

I will be comping the hand over the the footage once I paint out the talent. On the zMatte screen shot, I randomly moved the sliders just trying to get it to do something and nothing happens. I have Luminance for the setting to pull the key

I have provided screen shots for reference. Thanks again for the help.


When the View is set to Output, only a RGBA result is produced instead of a composite. Press the A key to view the alpha that is being generated and you will see a change when the sliders are adjusted.

Once again Marco, thanks for all your help. Something so simple that I completely overlooked.