Outline around objects in transparent `Viewport` when using Vulkan

YeldhamDev commented 1 year ago

Godot version

4.0.dev [2985a9a]

System information

Kubuntu GNU/Linux 23.04

Issue description

If you use a Viewport with transparent_bg enabled, and you also happen to use Vulkan for the rendering, and dark outline will be visible around the stuff inside:

Vulkan	OpenGL

Steps to reproduce

Create something with a Viewport (either a Window, or a SubViewportContainer).
Enable transparent_bg for it.
Now inside the Viewport create something that can have the same color with what is behind it.

Minimal reproduction project

ViewTransparentBug.zip

Braveo commented 1 year ago

This is currently happening to me with 4.1.beta2.mono as well. Using nearest seems to work fine, so I'm guessing linear accidentally interpolates with the transparent background's rgb values being 0,0,0?

jsjtxietian commented 1 year ago

Tested in Godot v4.2.dev (691634969) - Windows 10.0.19045 - Vulkan (Mobile) - dedicated NVIDIA GeForce RTX 3060 (NVIDIA; 31.0.15.3619) - 11th Gen Intel(R) Core(TM) i7-11700K @ 3.60GHz (16 Threads)

It seems in the provided MRP, at least in my test all three render mode gave the same result as :

godotengine / godot