90ms on landscape subsystem tick in a world partition level

poopipe

This is in editor rather than at run time - the problem is entirely on the game thread (gpu time is under 20ms)
Times double if the landscape is converted to nanite
Edit layers are disabled although that has made no diffrence


This is a 4km square landscape converted from normal level to WP (starting an empty WP level is incredibly broken atm)
there is nothing in the level apart from the landscape (with a nice material) and the sun position bp

I assume it's doing something to keep the landscape updated in editor time  but i'm not enjoying 8-10fps while trying to look at what im doing.
Anybody  got any suggestions for settings i can fiddle with to calm this shit down ?  google/unreal docs are typically useless

Alex_J

i'm just a knob fiddler and don't know much about what happens under the hood, but IME the biggest effect for landscape performance is adjusting the LOD's. The default settings are not balanced IMO, because I found that they could be cranked to much lower resolution while not having a visual impact. 

You are probably aware but i'll just mention it for posterity, but if tuning the LODs on landscape its helpful to use the wireframe on landscape view mode - dont remember exact name off top of head but its in one of those viewport VIEW dropdown widgets. This is helpful because the names of the LOD levels make no sense to me so its easier to just turn the slider and see what effect it has.

the other big thing is grass. if there isn't a lot to obscure long views and the grass draw distance is high, that makes a big effect.  What I tend to do is have most of the grass types cull very soon, and save just a few bigger scale grass types for longer distance culling, that way you see grass in the distance but there are much fewer instances.

poopipe

All true but it's not a rendering issue.   the amount of time on the gamethread seems to be directly related to the number of loaded tiles 

I'm made the project workable by building HLODs, only loading a relatively small number of tiles (8x8 = 40ms) and using the show HLOD in editor toggle 

its significantly slower than 5.3 though -  almost by an order of magnitude  so there must be something set to a stupid default somewhere in a config