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

That's awesome! Added this as an addendum to the post.

> Do you have advice on linear vs srgb space antialiasing?

Unfortunately, this is completely context dependent. One central point is, whether or not the graphics pipeline is instructed to perform corrections (GL_FRAMEBUFFER_SRGB in OpenGL), as that changes the answer. Another point is, in which context blending is performed. Luckily the developer has full freedom here and can even specify separate blending for alpha and color [1], something that GPU accelerated terminal emulator Alacritty makes use of [2], though it doesn't do MSDF rendering.

One thing I can say though: The alpha, the fading of edge, has to be linear at the end or perceived as such. Or rather if the edge were to be stretched to 10 pixels, each pixel has to be a 0.1 alpha step. (If smoothstep is used, the alpha has to follow that curve at the end) Otherwise the Anti-Aliasing will be strongly diminished. This is something you can always verify at the end. Correct blending of colors is of course a headache and context specific.

> fonts have been tweaked to compensate, so sometimes srgb is better

This should not concern MSDF rendering. These tweaks happened at specific resolutions with monitors popular at that time. Especially when considering HiDPI modes of modern window systems, all bets are off, DPI scaling completely overthrows any of that. MSDF is size independent and the "tweaks" are mainly thickness adjustments, which MSDF has control over. So if the font doesn't match as it looks in another rendering type, MSDF can correct for it.

[1] https://developer.mozilla.org/en-US/docs/Web/API/WebGLRender...

[2] https://github.com/search?q=repo%3Aalacritty%2Falacritty+ble...

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...

Disclaimer: I haven't really played games with high-end graphics on a high-end system in over a decade, and have always had more of a soft spot for games that use beautiful art design to work around the limitations of "underpowered" systems (IMO the graphics in those games hold up much better throughout the decades anyway). And as I mentioned elsewhere I'm generally quite lost when it comes to AA names and abbreviations. It would be disingenuous of me to tell a community I'm not part of what the best solution is for them.

However, on a meta-level I find something like “r/FuckTAA” fundamentally entitled and ungrateful to the people who put years of their lives into making these games. Of course the loudest gamers tend to be smaller subgroup of the entitled toxic ones, so perception is distorted anyway. Plus, I do get it to some degree: if you invest a lot of money and time into powerful hardware to get beautiful graphics, you'd like to actually get beautiful graphics out of it.

Still, every time I read any article on the technical workings of modern graphics, it strikes me as a community full of extremely passionate people who care about squeezing beautiful graphics out of the available hardware. There are nicer ways to say "sorry but this particular technical solution/aesthetic trend doesn't vibe with me".

(Obviously this is not aimed at your nuanced take with a sincere question for discussion. And thank you for the link, will watch, because the tech still is an interesting topic to me even if I don't play these types of games)

Ohh right! I'm sure the must be an Eleventy setting for that...

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.

I tried to do this for polygons rendered aliased by computing edge position and reweighting pixel colours. It looks great when polygons are large but it breaks for small polygons (when polygon size is close to pixel size)

True, this is something I struggled with writing and ended up with just a small note commenting that this is not widely applicable. Will clarify more in coming posts. It's all incredibly context specific. The reason for this order, is that you can very much can use all these approaches (SSAA, FXAA, MSAA etc.) for rendering simpler shapes and HUDs. So going through them, where these approaches break down and when it does make sense to go the extra mile with SDFs.

Still, non-standard rendering approaches are very much a thing [1] and I could see setups like [2] be used in scientific particle visualizations.

[1] https://www.youtube.com/watch?v=9U0XVdvQwAI

[2] https://bgolus.medium.com/rendering-a-sphere-on-a-quad-13c92...

What happens during overlap, is something you control fully, at every step. (Except when using this with MSAA, as that is implementation defined) How intersections happen when blending shapes of multiple draw calls or multiple quads is defined by the blending function you set before issuing the draw call. In WebGL the call is blendFunc() [1] and there are a bunch of options.

How to blend multiple shapes on the same quad, within a draw call is shown in the section "Drawing multiple?". There you fully control the intersection with the blending math.

Finally, there is always the gamma question, which is true for all AA solutions. This is not covered in the post, but that might mess with the results, as is true for any kind of blending.

[1] https://developer.mozilla.org/en-US/docs/Web/API/WebGLRender...

The blog is built with eleventy https://www.11ty.dev/ and as the previous reply already mentioned, the source code is on GitHub [2]. All posts are single Markdown file each with HTML inserted where I need it. The javascript for the demos is custom and changes from post to post. The basic style comes from Sakura CSS [3] with a bunch of custom stuff on top.

[1] https://www.11ty.dev/

[2] https://github.com/FrostKiwi/treasurechest

[3] https://github.com/oxalorg/sakura

Not the parent, but seems this is the source code for the blog. https://github.com/FrostKiwi/treasurechest

Found it by going to the comments since the comments are GitHub issues the "x comment" is a link to the issues page.

Yes, that also surprised me and I tested it on multiple mobile Apple devices. It's not really a mistake per se, the implementation is free to do what it wants. Selecting MSAAx2 on these types of mobile GPUs simply has no upside and isn't really supported over MSAAx4 and I guess apple still wanted to make the choice somehow possible, as opposed to Android, where there is only an illusion of choice.

It's just so happens to produce visible artifacts in this case. I suppose for 3D scenes it's mostly fine.

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