Document sub-pixel morphological antialiasing (SMAA)

[MJacred]

• For Godot 4.5, depends on merging Add SMAA 1x to screenspace AA options godot#102330

[tetrapod00]

The demo for generating the images is https://github.com/Calinou/godot-antialiasing-comparison, see this comment on the page:

godot-docs/tutorials/3d/3d_antialiasing.rst

Lines 6 to 8 in f8ce2c9

	.. Images on this page were generated using the project below
	.. (except for `antialiasing_none_scaled.webp`):
	.. https://github.com/Calinou/godot-antialiasing-comparison

[tetrapod00]

Looks good for docs formatting, and matches my casual understanding of the performance of SMAA. Still waiting on a merge of the engine PR, and will need another round of review at that time.

[MJacred]

Is it ok to add the info from here?

[clayjohn]

Is it ok to add the info from here?

Absolutely! Usage info like that is very helpful

[Calinou]

Should be good to merge after adding a tip about mixed SMAA + TAA/FSR2 usage, as mentioned above.

[MJacred]

Tip was added.

I just remembered reading in some Godot issue or PR that when combined with FSR2 it may yield worse results at higher cost and it's better to just use FSR2.
Sadly I can't find the source anymore… Is that true?