Roto Brush to Luma Matte

[Tudor “ted” jelescu]

You can always render out the layer with an alpha channel, import that back to your comp and use the alpha.
I am not sure if once you apply the rotobrush the track matte would work, but worth a try- let me know if it works.

Tudor “Ted” Jelescu
Senior VFX Artist

[Sarika Mirchandani]

You can apply Colorama effect to create a Luma Matte.

[Daniel Schmidt]

I guess, but that would not give me the desired result. I want a mask of the area I defined with the roto brush. Meaning, if I were to key out an arm for example, the area of the arm is full white, the rest is full black. Applying the Colorama effect would take the luminance levels of the footage (the arm) into account, which is not what I want.

I guess, I am just used to being able to have access to masks/mattes from Photoshop. Whereas the AE roto brush seems to “hide” the mask/matte it creates.

[Daniel Schmidt]

I actually need the black and white mask/matte for what I want to do next. But I guess that exporting workaround should work. I thought, there would be a more elegant solution though. Thanks!

[Sarika Mirchandani]

If you want the mask (created using roto brush)to be white in color
(matte),simply add ‘fill effect’ and change the fill color to ‘white’.

Now go ahead and duplicate the layer and simply check on the ‘invert the Foreground/Background’ field of the the roto brush and change the ‘fill color’ to ‘black’.

This will create a matte where the area you rotoed is white in color, meaning opaque and the rest of the area is black, meaning transparent.

Sorry if this is not what you are looking for.
Pls keep me updated.

[Sarika Mirchandani]

Actually ignore from the duplicate layer option.