anti aliasing has no effect

[sofar]

Enable shaders, mipmap and anisotropic filtering, then:

1. set antialiasing to (none). Take a screenshot
   
2. set antialiasing to (8x). Take another screenshot
   
3. Run:

composite screenshot1.png screenshot2.png -compose difference diff.png

4. Inspect the diff output image.

Expected outcome: various delta pixels all over the place.
Actual outcome: clouds moved, no other pixels differ

Conclusion: 8x antialiasing doesn't do anything.

[sofar]

What I'm looking for is something like this instead, after I force pp_jimenezmlaa_color=16 for instance:

[HybridDog]

FSAA works for me but I do not like it: #6860
There's an issue about removing the setting from the main menu: #8367

Changing the antialiasing setting only works when I fully restart minetest.

[Calinou]

Make sure your graphics driver isn't forcing MSAA in all applications. However, only the NVIDIA proprietary really offers this on Linux… (Moreover, this setting generally isn't effective in newer games, but it'll often work in applications using "legacy" OpenGL versions, including Minetest.)

[paramat]

Changing the antialiasing setting only works when I fully restart minetest.

Maybe this is the cause?

[juozaspo]

composite screenshot1.png screenshot1.png -compose difference diff.png

Make sure you're not comparing first screenshot against the same one in the command line (notice the second image is also named screenshot1), look for minor differences beetween screenshots and check command output image if it's shown there, look for things like clouds appearing in different spots or similar stuff

[sofar]

Make sure you're not comparing first screenshot against the same one

Was a typo in the bugreport. Note that the clouds appear in the delta - I was comparing and making the correct delta images.

[sofar]

Make sure your graphics driver isn't forcing MSAA in all applications.

I'm using the mesa radeonsi here in this case. Note my point about pp_jimenezmlaa_color=16 which shows that the hardware can do antialiasing properly.

[HybridDog]

Make sure your graphics driver isn't forcing MSAA in all applications.

In minetest it's called fsaa.
According to wikipedia, FSAA (full-scene anti-aliasing) is the same as SSAA (super-sampling anti-aliasing): https://en.wikipedia.org/wiki/Multisample_anti-aliasing#Definition, https://en.wikipedia.org/wiki/Spatial_anti-aliasing#Super_sampling_/_full-scene_anti-aliasing.
MSAA works differently because it only affects the edges of the graphical primitives (triangles); this can be seen in minetest:

Why is the setting in minetest called FSAA and not MSAA?

This is an excerpt from the first screenshot without minetest's antialiasing:

The nearest-neighbour interpolated pick texture has jagged edges and the edges of the wielditem mesh's triangle are smoothed, so I assume somehow there is MSAA enabled.

[Calinou]

Why is the setting in minetest called FSAA and not MSAA?

It was probably an oversight. Fixing it would break existing configuration files, but I guess it's a small breakage.

[paramat]

Changing the antialiasing setting only works when I fully restart minetest.

Maybe this is the cause?

This had no response, needs checking, could be the simple cause of this.

[Calinou]

@paramat I don't think Minetest supports changing MSAA at run-time. Therefore, you need to restart Minetest to apply MSAA changes.

Edit: I can confirm you need to restart Minetest to apply MSAA changes (tested with 5.3.0 on Linux + NVIDIA).

[paramat]

Thanks, this unconfirmed bug needs retesting then.

[paramat]

Seems likely to be a restart issue, and seems to work for others, so closing.
PR for improving docs in progress #10279