Ignoring the background color in a 2d screen shader

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:bust_in_silhouette: Asked By Kanor

I have a whole bunch of polygon2D nodes and they’re fantastic, BUT I want to apply a shader to all of them that adds a drop shadow.

Is it possible to make a large, overarching shader that recognizes the colors of JUST my polygon2D nodes and uses them? Like importing them as shader params or something?

Or, alternatively, could I use a textureLod(SCREEN_TEXTURE, SCREEN_UV, 0.0) in such a way that the game’s background color would have an alpha of 0 so I could make a screen shader that applies a drop shadow to all sprites?