Landscape editing is painfully slow in 4.8 promoted branch

Our artists are reporting that after upgrading to the 4.8 promoted branch, landscape editing has become slower by orders of magnitude. Any time we make even the tiniest modification to the landscape, we get the message “Baking Landscape Textures” as it re-cooks the textures, and that makes landscape editing super laggy and slow.

This has become a big productivity issue for us … let us know if there’s any way we can work around it until a fix becomes available.

This is totally connected to hard drive speed. Something has changed between 4.7 and 4.8 so that in 4.8 editing the landscape (particularly when sculpting!) is always accessing the disk (and displaying the message “Baking Landscape Textures”). If you have a good SSD then, despite a little lag as you start to sculpt, the performance is totally acceptable. But if you’re on a mechanical HDD, well, performance is terrible.

I’m not sure what changed - but performance has now fallen to unusable levels if you don’t have your project on a SSD.

Thanks for the info, Neil. Epic guys, do you know if this is something that will be fixed for the final 4.8 release? … Or will there be a setting available to allow us to continue working on landscapes without constant interruptions?

So I traced through the engine code and tracked it down to ALandscapeProxy::UpdateBakedTextures().

I saw that if either r.GenerateMeshDistanceFields or r.GenerateLandscapeGIData are false then it doesn’t really do much and then early-outs.

This was a smoking gun for me - because we DO set r.GenerateMeshDistanceFields to True in our DefaultEngine.ini - so that we can make use of Distance Field Shadows. But that setting makes sculpting the landscape more or less unusable for our artist.

For now I’ve set r.GenerateMeshDistanceFields to False on his machine so that he can sculpt without problems - but that’s just a temporary workaround. The problem, seemingly, is that it’s constantly trying to update baked textures while sculpting. I’m not sure what the right fix is for that (perhaps only do this on the mouse up event after sculpting?), I only know that this is a problem.

just disable in the project settings “Generate Landscape Realtime GI Data” and then you dont even must restart your editor.