Bug Report: Material standard PBR the leaves with alpha camera closer to mesh performance drops [Point Release 23.10.1]

Darkinggq commented 9 months ago

Describe the bug Not long ago I tested the original from lumberyard bistro https://developer.nvidia.com/orca/amazon-lumberyard-bistro on O3DE a lot of material with alpha performance drops worse

Screenshots/Video

Found in Branch point-release/23101

Commit ID from o3de/o3de Repository 1ac30e042c023f493256b2690c0b0849910e3d49 (HEAD -> point-release/23101, origin/point-release/23101)

Desktop/Device (please complete the following information):

Darkinggq commented 9 months ago

if opacity disable performance increase, opacity enable mode Cutout/Blended/Tinted Transparent the fps result drops

moudgils commented 9 months ago

Bistro demo (from what I remember) is just one big mesh chunk. So nothing is getting culled or occluded. It was not optimized for perf.
It seems that (cant confirm without looking at gpu profiler numbers) you are gpu bound. That is usually the case when someone does not build out shader variant list for their content. The variant list allows us to create performant shader variants which are then used at runtime instead of the root shader variant which is very expensive as every branch in it is dynamic (GPUs hate branches as it kills parallelism). Unfortunately the core engine does not ship with a variant list as the list is content dependent. You have to manually use Shader Management Console to run a python script to crawl your materials and build a simple shader variant list which can be further expanded to get more performance. We do plan on releasing videos + documentation on how to do this with easy steps. For more information about SMC go here - https://github.com/o3de/o3de/wiki/%5BAtom%5D-Shader-Management-Console-(SMC).

moudgils commented 9 months ago

We will add videos on how to easily generate variant list. We should re-visit this issue after testing with a proper variant list.

o3de / o3de