version: 2.80 (sub 74), branch: blender2.7, commit date: 2019-06-13 19:32, hash: 5e626e766459, type: Release
build date: 2019-06-14, 00:10:01
platform: Linux (I can post the full system info output if it is helpful.)
How to reproduce:
- Open the file
- Change Display Method to Rendered or LookDev
- Enter Walk or Fly Navigation
- Leave the mouse and Viewport still (nothing should move)
- Watch a noisy area of the scene closely, like the reflective floor
You should notice a "pulsating" effect in the viewport. The effect is easier to see in parts where there is high contrast in the Ambient Occlusion or Screen Space Reflections. If your system specs are extremely high or low, it may require adjusting the viewport sample count to be apparent.
I'm not familiar with how AA sampling works in Eevvee (or if it is even correct to call it AA), but it appears that in normal navigation mode, when the scene is not moving, Eevee stops sampling when it reaches the viewport samples number. This is expected. However, in Walk/Fly navigation mode, the sampling just "loops" endlessly, starting over after it reaches the end, so that the viewport never displays the final result. This looks bad and probably wastes system resources.