Resolved regression: importing an .mb or a large .fbx hangs unity HDRP+DXR at 100% CPU usage ( IN-14859)

i would swear that unity used to be good at importing maya file so I dug in a little more: opened up the task manager and saw the two phases of import very clearly:
1. some Maya activity, converting the .mb file to .fbx then sends it to unity
2. unity churns that fbx into its own soup
1. happens with no problem in less than a minute but 2. gets stuck forever, this one I let run for 2 hours. So that's not a maya problem. I don't know what Unity is doing but it sure is enjoying all the cores it can chew on, doesn't look like shader compile (a HDRP specialty)



so I tried the same op in 2020.3.38 and here is what i saw


maya phase 1... all bueno

then unity phase 2... drumroll



bam, it worked!!



so yeah 2022 with HDRP like to churn forever, 2020.lts with stock 3d project have no problem so maybe it's hdrp breaking things again.

hopefully you'll fix that before release because I'd like to render this sequence with pathtracing on, you know, using timeline for offline rendering like ... that other game engine.

 

correction: this also happens in stock 2022.2 3D, newly installed b5 as well and with an fbx version of the maya file.

I'd call that a showstopper.

2022.2b5 and ongoing



2020.3.38 less than 3 minutes

 

even unreal, which is notoriously crap at importing fbx files, chewed through this one. so yeah, fbx importer has a problem.
logged again as IN-14863 , this time with an isolated fbx file