Godot version

v4.0.beta.custom_build [ca25c6e]

System information

Arch Linux, KDE, AMD RX6800XT, Mesa, Vulkan, Clustered+

Issue description

Temporal Anti-Aliasing seems to recieve no motion vectors for skybox textures, resulting in motion smearing when rotating the camera.

This is especially aparrent with textures detailed enough so that TAA's blending threshold doesn't kick in:

Here's an example with PhysicalSky using a spreckly FastNoiseLite texture in the "Night Sky" slot to imitate stars. ooking around causes massive smearing. Note the difference between the textured ground and the sky - both were moving the same way on-screen.

Steps to reproduce

Use a very grainy, 4x2K resolution texture and put it either into PhysicalSky's Night Sky rtexture slot or into PanoramicSky.

Minimal reproduction project

Here's a simple project that demonstrates this with a rotating camera:

TAA vs Skybox.zip

I've also added an alpha-blended sprite to demonstrate how transparency overwrites motion vectors for anything that's behind it regardless of alpha value.