Severe frame-to-frame flickering noise on vegetation despite static settings and cinematic Anti-Aliasing

[ssaigarimella]

Cosys-AirSim commit or version: 5.2.1
Unreal Engine version: UE5.2.1
Graphics API (DirectX / Vulkan / etc.): Vulkan
OS: Ubuntu 22.04
GPU: NVidia RTX 4090

When capturing frames in my Unreal Engine 5.2.1 simulation using Cosys-AirSim with all motion animations (wind, foliage sway, etc.) disabled, and Anti-Aliasing set to Cinematic, I still observe significant flickering/noise on vegetation (trees and leaves) between consecutive frames (please view example attached images). The vegetation is set to be perfectly still, and LOD/texture streaming have been disabled where possible, but the flickering persists.

1. Use Cosys-AirSim with UE5.2.1.
2. Disable all wind and foliage motion (wind settings in project + material WPO).
3. Set Anti-Aliasing Method to Cinematic.
4. Disable StaticMesh LOD switching.
5. Capture sequential frames along a camera trajectory.
6. Observe frame-to-frame noise/flickering in vegetation areas.

Vegetation should render consistently between frames when static settings are applied, without flickering or noise change frame-to-frame, matching expectations for deterministic dataset capture.

I have attempted disabling:

• Wind and foliage animation
• Nanite on meshes
• Texture streaming
• Foliage LOD switching
• Distance culling
• Anti-Aliasing set to Cinematic
  Yet the vegetation still shows frame-to-frame intensity/noise changes, which impacts dataset quality.
  This appears to be inherent to how foliage is rendered or sampled between frames, even when static.
  Capturing for deterministic datasets such flickering breaks ML training and evaluation.