Vulkan: VoxelGI and SDFGI flicker when TAA is enabled

[MisfitVillage]

Godot version

4.0.alpha10

System information

Windows 10, RTX3070 laptop, Vulkan

Issue description

TAA makes VoxelGI flicker (I also toggle on and off FXAA in the video to show that does not affect the flickering):

173898921-9f6ad1f4-40ec-4952-a7e1-e0963903a4b6.mp4

Steps to reproduce

Put a VoxelGI node into your scene, enable TAA in the Project Settings. Bake the VoxelGI. You will notice a flicker in the reflections and GI, especially if you turn on "VoxelGI Lighting" view under "Display Advanced".

Minimal reproduction project

godot TAA VoxelGI Bug.zip

[Calinou]

I can confirm this on 4.0.alpha 421d8b7 (Linux, NVIDIA).

Some comments:

• Remember to enable Update Continuously in the Editor Settings to see the flickering in action (or enable Perspective > View Frame Time in the 3D editor viewport, which forces continuous redrawing).
• This is made more obvious by the various effects you've enabled in the Environment resource (autoexposure, glow, SSR). If only VoxelGI is enabled and all other effects are disabled, this is only noticeable with some camera angles. It's also more noticeable at lower resolutions than high resolutions, which is why the video recordings below were made with a small editor window size:

simplescreenrecorder-2022-06-15_22.44.28.mp4

simplescreenrecorder-2022-06-15_22.44.47.mp4

• SDFGI is also affected by this issue:

simplescreenrecorder-2022-06-15_22.45.35.mp4

[Calinou]

Still reproducible on 4.0.beta7 (Linux, AMD Radeon RX 6900 XT with RADV).

A tangential issue is that when the camera starts rotating after moving, reflections can appear to "snap" into a new position, which looks jarring. This only occurs with TAA enabled, and it occurs with both SDFGI and VoxelGI.

Testing project: test_voxelgi_taa_reflection_bug.zip

[MisfitVillage]

On 4.2.6 with FSR2 set to render scale 0.5 the flicker is even worse. I also toggled all the postefects on and off to prove it's based on turning on/off VoxelGI.

2023-10-04.15-31-14.mp4

[DenisLevy76]

I'm experiencing the same issue with Godot 4.2.2. When I enable TAA and FSR2, certain elements in the scene start to flicker, even with SDFGI or VoxelGI disabled.

github.mp4