It is still present in Max 2022 and after 10 minutes of not interacting the color bars keep flickering from time to time, which indicates it is constantly running.
In Max 2021 and 2022 the SDK ViewportDisplayCallback is also constantly called, except when Max loses focus, as far as I could test.
For upper photo and scene:
Max 2015. Everything that matters here on default values
-AO and shadows – on
-Sky(light) default values
-Material – what is considered as “no material” – gray 110
-(Over)contrasted thru Mr exposure – “2d -post-rendering” effect – to clear things a little, can show “bad things”
-1 Omni light only affecting specular – not using progressive refinement
Changed – Yes.
I guess nvidia-MRay leaving didn’t go so well and smooth
I can talk about 2015 vs 2021 differences – don’t know when started.
-Default material/s (or “No Material”) is/are changed – can’t be in same scene – nothing will work as it should
Can’t believe this was the only way to translate Arnold shader- Physical mat. to HLSL
-Dealing with transparency changed
-AO changed, now gets baked in – no refinement – very different look with same values
BTW couldn’t get G-buffer channels display in viewport in 2021.
I don’t know if any of mentioned methods can be (or how) used for IsProgressiveRenderingFinished.
Calling that alone repeatedly can give different result – with no changes in Max/Viewport
Al I know is in 2021 refinements are shorter and much sooner get “baked in” – not reacting on every event.