AAA – Analytical Anti-Aliasing • Hacker News Board

Re: AAA – Analytical Anti-Aliasing

#61

Post by globular-toast » Wed, Nov 20, 2024, 10:05 PM UTC

> Mobile chips support exactly MSAAx4 and things are weird. Android will let you pick 2x, but the driver will force 4x anyways.

Hmm... On my Android phone I definitely see a difference between 2x and 4x, but it's not "rounded" like the iPhone one.

Re: AAA – Analytical Anti-Aliasing

#62

Post by kbolino » Wed, Nov 20, 2024, 10:20 PM UTC

Waterluvian wrote: post #59

art0rz wrote: post #25

Earlier quoted context omitted.

I really dislike TAA, especially on lower framerates. There's too much ghosting. I often switch it to a slower algorithm just so I don't get ghosting.

My feeling is if I can render at 4K I can just not do AA at all. It really looks quite fine without, at least for me.

No AA on 4K/high-DPI has been almost perfect for me, but I still occasionally notice thin edges flickering and objects getting dithered when fading in or out. It's definitely better than TAA though, which just ends up smearing everything that moves.

Re: AAA – Analytical Anti-Aliasing

#63

Post by zadler » Wed, Nov 20, 2024, 10:30 PM UTC

FrostKiwi wrote: post #2

Thanks for sharing! Author here, happy to answer any questions.

Massive thanks for this! I’m already using my own version of analytical antialiasing but there were some bits I couldn’t get quite right so this is perfect!

Re: AAA – Analytical Anti-Aliasing

#64

Post by ferbivore » Wed, Nov 20, 2024, 10:48 PM UTC

mastax wrote: post #55

ferbivore wrote: post #5

Earlier quoted context omitted.

> Mobile chips support exactly MSAAx4 [...] the driver will force 4x anyways On what GPUs and through what APIs did you see this? This seems fairly weird. I especially wouldn't expect Apple to have problems.

I’m definitely seeing similar artifacts when at 2x on an iPhone 15 Pro.

Through Metal or in a web browser? Apple's docs say it's supposed to use the standard 0.75/0.25 sample positions with 2x MSAA: https://developer.apple.com/documentation/metal/mtldevice/28...

Re: AAA – Analytical Anti-Aliasing

#65

Post by wizzard0 » Wed, Nov 20, 2024, 10:52 PM UTC

those buttery smooth gradients are soooo pleasing to watch <3

Re: AAA – Analytical Anti-Aliasing

#66

Post by aappleby » Wed, Nov 20, 2024, 10:54 PM UTC

delusional wrote: post #54

aappleby wrote: post #51

Earlier quoted context omitted.

Google Maps uses AAA on capsule shapes for all road segments - I wrote it ~10 years ago. :D

Neat. Does that mean that every road segment is a separate mesh?

Depends on what you mean by "mesh". Each road segment is an instanced rectangle that gets extruded and beveled so that it fits tightly against adjacent segments, and then the pixels are shaded using AAA (with a capsule-shaped distance field) so that the result looks like an antialiased wide line with round end caps and joints.

Re: AAA – Analytical Anti-Aliasing

#67

Post by mastax » Thu, Nov 21, 2024, 1:13 AM UTC

ferbivore wrote: post #64

mastax wrote: post #55

Earlier quoted context omitted.

I’m definitely seeing similar artifacts when at 2x on an iPhone 15 Pro.

Through Metal or in a web browser? Apple's docs say it's supposed to use the standard 0.75/0.25 sample positions with 2x MSAA: https://developer.apple.com/documentation/metal/mtldevice/28...

Viewing the article in Safari.

Re: AAA – Analytical Anti-Aliasing

#68

Post by 01HNNWZ0MV43FF » Thu, Nov 21, 2024, 1:20 AM UTC

Now I'm very curious about analytical AO and shadows as you mentioned Last Of Us uses. I'd heard about the spheres but never seen an explanation of how they get turned into shadows

Re: AAA – Analytical Anti-Aliasing

#69

Post by Arelius » Thu, Nov 21, 2024, 1:46 AM UTC

enbugger wrote: post #24

FrostKiwi wrote: post #2

Thanks for sharing! Author here, happy to answer any questions.

As a non-gamedev person but just gamer, I should expect that this will replace TAA anytime soon? Should it replace TAA?

Basically no... Analytic AA is a really hard problem for video games, and I know of no general purpose solutions.

For font and 2D vector rendering it's likely, in fact afaik, some solutions, such as Slug already do.

But for 3d rendering I don't know of any solutions.

For an intuition, consider two triangles that intersect the same pixel.

Consider if say one has 20% coverage and the other 30%, does that pixel have 50% coverage, 30% by one, 20% by one and 10% by another, or any other conceivable mix? It's very difficult to say without selecting specific points and sampling directly.

Re: AAA – Analytical Anti-Aliasing

#70

Post by FrostKiwi » Thu, Nov 21, 2024, 1:46 AM UTC

Lerc wrote: post #30

FrostKiwi wrote: post #2

Thanks for sharing! Author here, happy to answer any questions.

How long did this take to write? I have done a few live visualization based blog posts, and they take me ages to do. I kind of think that's the right idea though. There is so much content out there, taking longer to produce less content at a higher quality benefits everyone.

The commit history [1] reveals that, took a while. I don't write professionally, something I do in lunch breaks from time to time. Thanks for the kind words.

[1] https://github.com/FrostKiwi/treasurechest/commits/main/post...