How to clear final scene with transparent color instead of solid color?

Unity Engine
1

Hi

I’m trying to make final scene semi-transparent with per-pixel transparency.

I’ve tried:

  • To set Camera.backgroundColor but it ignores alpha value of color and just fills the entire screen with solid color.

  • To not clear scene but it’s not desired result because picture starts to accumulate and it still has gray background.

  • To place transparent background quad but this also didn’t work.

Ultimate goal: I want to draw Unity scene on top of other content in Windows Store application.

It is possible with DirectX if you set Clear color as transparent, but looks like Unity ignores transparency on final render and just uses RGB to clear scene before render.

Because Unity uses DirectX internally and DirectX can do this, it’s not impossible task.

Is there a way to make final render with transparency?

2

I think you can render a full screen quad before doing anything else with a shader that just writes 0,0,0,0 to the background color to force a clear with 0 alpha.