We are getting some significant problems rendering our landscape on OpenGL4.3 on Ubuntu 14.04. Certain squares within our landscape are being rendered at incorrect height offsets (with what looks like vertical landscape in those areas), and other areas seem to have the odd colouring effects.
The landscape/material works perfectly on Windows, and on Linux the collision on the landscape is still correct - things are just drawing incorrectly.
This problem occurs on both 4.11.2 and 4.13.1 (built from source code). Also, we are using more than 16 texture samplers in the landscape material, and so have applied the patch to allow this, outlined here https://github.com/EpicGames/UnrealEngine/pull/2610
Update: I’ve tried this with OpenGL4.3 on Windows under 4.11, and got the same problem
Update2: It seems that each square landscape tile has the same quarter broken, and the other 3 quarters work fine, at least as far as position goes (weird colours aside). Its the top left quarter, if you are looking down at the landscape, with X increasing to the right, and Y increasing downwards (towards the bottom of the screen)
Any help is much appreciated!