Hello! How can I create luma matte mask for ShotStack? I don’t have it but I have normal video, alpha mask video and green screen video.
To create the luma matte you will need to create a black and white/greyscale animation that matches the shape of the alpha channel. I think you will need to prepare this in After Effects or similar as Shotstack does not create the actual luma animation. Once you have the matte animation video you can apply it as a mask using the luma asset.
Have a look at the tutorial here How to create transitions using luma mattes — Shotstack which shows you what the luma matte should look like and how to apply it. The tutorial is for a transition effect but it should work the same if you want to create a regular mask or greenscreen type mask.