Isn't that a solution for an overdraw problem? I mean if you put a giant number in it - "transparent" pixels will be behind a skybox and theoretically do not render at all, while a shader will remain opaque. Am I correct? Or I misunderstand something?
Short answer: PDO is more expensive than Masked Opacity and can be just as expensive as transparency, so it's a poor choice to use as a replacement for Masked Opacity. Just use masked opacity. Longer answer: First lets make clear the terms we're talking about. Masked opacity usually refers to the binary calculation that…