Smeary visuals with TAA on since switching my project to Godot 4.4

[jijigri]

Tested versions

-Reproducible in Godot 4.4
-Not reproducible in Godot 4.3 and prior

System information

Windows 10 - Godot 4.4 (Forward+) - NVIDIA RTX 2080 SUPER - 32 GO RAM - Intel Core i7-9700KF

Issue description

After switching my project from Godot 4.3 to Godot 4.4, I'm being met with a lot of strange visual artifacts, like the entire game is "smeary".
It seems to only happen when having TAA turned on, but having TAA on in Godot 4.3 didn't result in these artifacts (or at least not as noticeable).
It happens in Editor and in build, and running an older build from Godot 4.3 works completely fine.

One thing to note is that having a screen shader (via creating a plane mesh) makes the effect worse, but it still happens without the shader.

3dcda66b0e67229b92b25a93c459d76b.mp4

SugarOverdrive_4qVvqSW2Uq.mp4

Steps to reproduce

Turn TAA on

To make the effect more noticeable (on my end):
-Create a new MeshInstance3D and set its mesh to a QuadMesh
-Enable Flip Faces
-Set its width and height to 2
-Set its material to a shader material and apply this shader:

shader_type spatial;
render_mode unshaded, fog_disabled;

uniform sampler2D screen_texture: hint_screen_texture, repeat_disable, filter_nearest;

void vertex() {
  POSITION = vec4(VERTEX.xy, 1.0, 1.0);
}

void fragment() {
	vec4 color = texture(screen_texture, SCREEN_UV);

	ALBEDO = color.rgb;
	ALPHA = color.a;
}

Minimal reproduction project (MRP)

issue103629_mrp.zip

[and-rad]

It's a result of #86809. I also have to say that the ghosting is noticeable now and the blurriness is extremely noticeable. I think a proper set of config parameters for TAA need to be exposed going forward because as it stands now, the loss of image clarity is too much of a downside.

[akien-mga]

Why close? It sounds like at least with default settings, there's a loss in quality which wasn't anticipated in #86809, so that may qualify as a bug (rendering maintainers will judge).

[clayjohn]

I suspect the solution here is to allow disabling motion vectors for things like the full screen quad (possibly with a render mode like in #77523).

In 4.3 the full screen quad trick wasn't an issue because we rejected all previous samples in motion anyway. But now it's possible to overwrite the motion vectors and truly break TAA

[jijigri]

Why close? It sounds like at least with default settings, there's a loss in quality which wasn't anticipated in #86809, so that may qualify as a bug (rendering maintainers will judge).

Sorry about that, reopened it for now

[clayjohn]

@jijigri Can you upload an MRP so that we can work on a fix?

[jijigri]

Edited to add an MRP