eca0c95d51
This adds a new parameter to the "Combined" overlay mode of the mask editor. The "blending factor" allows users to blend the mask exterior with the original footage to visualise the content of the mask in a more intuitive way. The "Alpha" overlay is unaffected by this change. The existing "Combined" overlay is used like before (covering everything outside the mask in black), but can be blended with the slider in the mask overlay to look at the exterior. This is part of an effort to make mask editing more intuitive & easy to use: https://developer.blender.org/T93097 Differential Revision: https://developer.blender.org/D13284