koobas.hobune.stream
What are the differences between Progressive GPU and Progressive CPU lightmapping?
I've recently been messing around with baking and lightmaps and noticed the Lightmapper drop down menu in the Lightmapping Settings. Quickly after inspecting the Progressive CPU and Progressive GPU options I've concluded that this has to do with what hardware the lightmapper uses to bake the lightmaps.
And it seems that I'm right since baking with Progressive CPU ramps up my CPU usage and Progressive GPU eats up VRAM (but doesnt affect overall GPU or CPU usage?). Also as expected, the Progressive GPU also has vastly higher Bake Performance - 150mrays/sec compared to 5mrays/sec when using the Progressive CPU.
But after baking with both options enabled i noticed that Progressie CPU is often faster and more reliable than Progressive GPU despite having vastly lower performance. Looking at what Lightmapper shows when baking, it seems that when using GPU Progressive the lightmapper is over and over baking last few lightmaps and snapping between completed and not completed before finally finishing after 20 or so tries as shown on the gif:
https://imgur.com/a/CNqRDhi
It also appears as though the baking times are inconsistent when using the Progressive GPU sometimes finishing the lighmaps of the same simple scene in 2 seconds, and sometimes in a minute or two. Progressive CPU on the other hand finishes baking just as the "Progress Bar" reaches the end in around 20 seconds consistently.
I haven't found much info online comparing the two. What do these options change, and which one should i use?
In case this is an error I'm working on Unity 2020.1.6f1 and these are my current Lightmapper Settings: https://imgur.com/a/MxLDQwP
