Terrain Brushes all squares & terrain destroyed on Undo

Hello everyone,

The terrain feature is not working properly in my Unity projet :

First problem (see image 1) : every brush are flat square alphas, even though the thumbnail displays correctly in the inspector.
This happens with height brush and texture brush, custom and built-in.

Second problem (see image 2) : if I use these brushes on the terrain, then press undo (ctrl+Z), the terrain gets messed up.

I attached my terrain settings

I tried reimporting the package, deleting project's library files, creating new terrain objects and terrain datas, upgrading the unity version for this project, the bug remains.

However, if I create a new project with the same Unity version, there is no bug and the terrain is perfectly functional. As a workaround, I can still copy/paste all my Asset folder in a new project's asset folder, but that's a bit annoying.



The problem appeared on my projet on 2018.3.1f1 and keeps going now I'm on 2018.3.3f1.
There are multiple posts about this bug on the net, some 2 years old, still unanswered.

Thank you very much for helping me solving this critical issue

Valentin Besson

 

Ok, I seemed that deactivating DirectX12 fixes the problem.