Anisowhatevertheheck questions

[Shenanigunner]

There are two binds for anisotropic filtering, and I can't usefully sort them out. Someone with more hackery understanding of video settings, maybe?

 

/fsaa either reutrns the current setting (0-16) or sets it. The only effect it seems to have is that setting it much past 4 hammers the FPS. If there's a visible effect at any setting, I can't see it.

 

/texaniso also returns the current setting and allows setting 0-16. It supposedly reloads the textures as well. While I can see the difference between 0/2, 8 and 16, it has no effect on framerate.

 

In technical terms, what the 'ell am I looking at here?

 

(BTW, /maxaniso returns your card's max setting, pretty much always 16 these days. But I'm not sure what actual function it's reporting...)

[Luminara]

FSAA is full screen anti-aliasing.  Because pixels are square or rectangular, whenever a line isn't perfectly vertical or horizontal, the individual pixels used to draw the lines create little saw blade edges,  FSAA renders each frame at 2x, 4x, 8x or 16x the resolution, then scales it back down so the jaggies become less noticeable, or disappear entirely (settings above 4x).  How visible the jaggies are depends partially on display size and resolution.  The higher the resolution, the finer the pixels and the less noticeable the jaggies... but extremely large monitors counter that.  On my laptop with a 15" display, running at 1920x1080, jaggies aren't so distinct that they catch my eye, so I can use 2x FSAA.  If I had a 50" external display, they'd be very distinct and I'd want to use 4x or 8x, maybe even 16x, or run the 50" display at a much higher resolution.

 

FSAA isn't related to anisotropic filtering.

 

Anisotropic filtering improves texture rendering when viewed at a sharp angle, to make textures sharper and clearer .  If you disable anisotropic filtering, you'll see a band of blurriness on the ground a short distance away from your character.  With each level of anisotropic filtering applied, that band of blurriness is pushed farther away, and with enough anisotropic filtering, it's too far away to differentiate the blurriness from normal gradience (level of detail).

[Luminara]

 

Okay, here's an example of jaggies.  This is one of the power lines in PI.  Note the stairstep pattern.  You can see it on the side of the building, too.

 

 

Same power line and building with FSAA (don't remember if i set it to 4x or 8x, and doesn't matter because this is just to show what FSAA is doing, not to what degree at what setting).

 

Both of these are scaled up 300% from the original resolution in order to clearly show the difference, so it's not quite that dramatic in the game, but it is visible.

 

2x FSAA reduces, but doesn't remove, the jaggies.  4x FSAA reduces the jaggies enough that they're not noticeable unless you're actively trying to find them.  8x FSAA makes the jaggies go away even if you're hunting for them.

 

Now, earlier, I said that FSAA renders every frame at 2x/4x/8x and scales it down.  There are actually half a dozen methods of FSAA, with different approaches to the problem, but this is an old game, and even when it was officially supported by the people who created the engine, they weren't exactly doing their utmost to push the limits of modern (at that time) graphics card capabilities, so the FSAA used here is almost certain to be that basic over-rendering and downscaling.  Unfortunately, while AMD's GPUs run OpenGL applications, most of the user-accessible driver settings don't work for OpenGL, only DirectX and Vulkan, so I can't test how different FSAA methods impact performance.

 

I also can't get any screenshots of different anisotropic filtering settings in action.  There's no visual alteration when I adjust the setting, despite it saying that it updates on the fly, nor does it change after /reloadgfx.  It might be a driver bug, it might be that another setting in AMD's Adrenalin control panel overrides AF or sets it to max at all times (the control panel setting says it only affects DX9 games, and there's no change when i turn it on/off), or it might be that it only changes if the game is exited and restarted.  I don't know.  But I can show you what anisotropic filtering does.

 

 

At the top, you can see the double yellow divider line just disappear.  That's where the textures become blurry and indistinct.  I doubled the size of this picture so it would be easier to see, but you'll have to open it outside of the browser window to get the full effect.  Anisotropic filtering is why that blurry band isn't closer.  If I could turn it off, that blurry region would appear roughly where the white lines start.  Each step up, from Off to 2x to 4x and so on, would push the blur farther back, and at 16x it would be waaaaaaaaaaaaay off in the distance like it is here.

[EnosFay]

6 hours ago, Luminara said:

 

Okay, here's an example of jaggies.  This is one of the power lines in PI.  Note the stairstep pattern.  You can see it on the side of the building, too.

 

 

Same power line and building with FSAA (don't remember if i set it to 4x or 8x, and doesn't matter because this is just to show what FSAA is doing, not to what degree at what setting).

 

Both of these are scaled up 300% from the original resolution in order to clearly show the difference, so it's not quite that dramatic in the game, but it is visible.

 

2x FSAA reduces, but doesn't remove, the jaggies.  4x FSAA reduces the jaggies enough that they're not noticeable unless you're actively trying to find them.  8x FSAA makes the jaggies go away even if you're hunting for them.

 

Now, earlier, I said that FSAA renders every frame at 2x/4x/8x and scales it down.  There are actually half a dozen methods of FSAA, with different approaches to the problem, but this is an old game, and even when it was officially supported by the people who created the engine, they weren't exactly doing their utmost to push the limits of modern (at that time) graphics card capabilities, so the FSAA used here is almost certain to be that basic over-rendering and downscaling.  Unfortunately, while AMD's GPUs run OpenGL applications, most of the user-accessible driver settings don't work for OpenGL, only DirectX and Vulkan, so I can't test how different FSAA methods impact performance.

 

I also can't get any screenshots of different anisotropic filtering settings in action.  There's no visual alteration when I adjust the setting, despite it saying that it updates on the fly, nor does it change after /reloadgfx.  It might be a driver bug, it might be that another setting in AMD's Adrenalin control panel overrides AF or sets it to max at all times (the control panel setting says it only affects DX9 games, and there's no change when i turn it on/off), or it might be that it only changes if the game is exited and restarted.  I don't know.  But I can show you what anisotropic filtering does.

 

 

At the top, you can see the double yellow divider line just disappear.  That's where the textures become blurry and indistinct.  I doubled the size of this picture so it would be easier to see, but you'll have to open it outside of the browser window to get the full effect.  Anisotropic filtering is why that blurry band isn't closer.  If I could turn it off, that blurry region would appear roughly where the white lines start.  Each step up, from Off to 2x to 4x and so on, would push the blur farther back, and at 16x it would be waaaaaaaaaaaaay off in the distance like it is here.

Thanks for answering, you made my day.

[Shenanigunner]

The road stripes were where I noticed the texaniso affect the most. Oddly, it has no effect on framerate.

 

But yes, very good answer from Lumi. I'm not exactly new to this stuff — I've done graphics workstation hardware design — but the command/game explanation etc. was pure murk.