The terrain tools load all the heightmaps of all the brushes and not just the one that’s currently selected in the palette. This leads to a quickly arising memory issue, you go up to 10 GB in no time, ie install terrain brushes into the project and click the terrain gameobject => out of memory.
I have difficulties especially with texture painting. It get’s laggy sooner or later and then chrashes if I don’t restart. I am not sure it’s related to what you mention. It works flawlessly on pretty much the same project on 2022.2.0b3 while on 2023.1.0a25 and now still on 2023.1.0b1 it crashes. It’s somewhat reproducible with a new project on my machine. Maybe I a file another bug report, if it’s something different.
I just got this message for example:
ok, after messing around more with a new project on 2023.1.0b1, I filed a bug report after it crashed, with the following text:
In a new project create a terrain and set height map resolution to 4097*4097
Then click with raise terrain brush rapidly around.
In my case it is laggy from the beginning and sooner or later crashes the editor.
Might be system dependent though.
I noticed that it writes in the range of hundreds of MB/s to the disk when clicking rapidly. It doesn’t do this, when just clicking once and holding.
I didn’t see this behaviour on older Unity versions.
General Discussion has a thread where this issue was brought up, and the simple version is that it’s not trivial to fix but there is a change going through that will alleviate some of the overhead.
Terrain: Enabled loading of brushes for the Terrain Inspector to now defer creating full-resolution brush textures until the brush is being used, making the Terrain Inspector faster to open and use less memory.