Here is an implementation of SMAA from here: http://www.iryoku.com/smaa/
Source Code: https://github.com/rextimmy/Torque3D/tree/SMAA
If someone wants to take this further and produce an official pull request, please go ahead but do note........
There are a few problems:
1) There is a problem with OpenGL. It works perfectly on Direct3D 9 and even our own experimental Direct3D 11. With OpenGL something goes wrong in the second pass(blend weights). I'm not sure if it doesn't like the texture format or it's something else? i'm just not sure. We don't use OpenGL so i didn't bother tracking it down any further.
2) This really needs to be implemented with some sort of options menu that handles the different quality levels or even the different AA options (i.e FXAA). In DM we have done this but that code won't be compatible with T3D, so i have trimmed this implementation down to suit. I tried to comment where i could in the source files about this.
Any questions just ask and i'll try and point you in the right direction.
Sorry i only had time to do one round of screenshots here. Biggest difference you will notice between SMAA/FXAA is the vegetation in these screenshots.
SMAA is definitely more expensive than FXAA. What i have found though (from testing on a few different GPU/CPU combos), the difference can be negligible if you have a recent rig. T3D is so CPU bound for any mid->high GPU/CPU combo, that the GPU spends more time idling than it does actually working I.E this extra work SMAA makes it do, makes no difference to frame rate for those set-ups.