This works for me.. to enable AA on PoE for Linux.
Nvidia proprietary driver -
[user@test ~]$ nvidia-settings --query=fsaa --verbose
Attribute 'FSAA' (mars:1.0): 0.
Valid values for 'FSAA' are: 0, 1, 5, 7, 8, 9, 10, 11, 12 and 14.
'FSAA' can use the following target types: X Screen.
Note to assign 'FSAA' on the commandline, you may also need to assign
'FSAAAppControlled' and 'FSAAAppEnhanced' to 0.
Valid 'FSAA' Values
value - description
0 - Off
1 - 2x (2xMS)
5 - 4x (4xMS)
7 - 8x (4xMS, 4xCS)
8 - 16x (4xMS, 12xCS)
9 - 8x (4xSS, 2xMS)
10 - 8x (8xMS)
11 - 16x (4xSS, 4xMS)
12 - 16x (8xMS, 8xCS)
14 - 32x (8xMS, 24xCS)
Using mode 9 gives me a pretty good quality of AA. So in Steam, under launch options for Pillars of Eternity, i set
__GL_FSAA_MODE=9 %command%
Credits to uoou - https://www.reddit.com/r/linux_gaming/comments/30dysl/pillars_of_eternity_is_ready/cpsp0hr