Maybe it's targeting a different use-case, but these things (at least on the Web) appear to be more-heavyweight and less-capable than the things people were doing 20 years ago with Macromedia/Adobe Flash, e.g. compare the animated-GIF-like examples linked from TFA ( https://thorvg-perf-test.vercel.app/ ) to the animations and games found on sites like Newgrounds. Last I checked, the latter make heavy use of emulators like Ruffle, or (based on loading screens) 3D game engines like Unity etc.

As someone who's been out of that scene for a long time: what's the overall state of things, if I want to make long, complex, 2D vector animations? (i.e. not using a 3D engine; and not rendering to video). SVG seems pretty established; but for animation, how capable is Lottie? Does anyone still use SMIL (outside of DVD menus)? Am I better off "rendering" to a big pile of JS + CSS transitions?

In inkscape you can make only a one direction gradient, never a gradient with more than 2 points, I don't know if it is a limitation of the format itself.

Also when you have multiple gradients in one file, the software becomes extremely slow. And they don't mix correctly when overlapped with transparency.

It seems a low hanging fruit to optimize that, but I guess there is little traction

But then it goes on to say that "interactivity" is unsupported. Embedded UI would be the first thing I'd be interested in using this for; wouldn't that be hampered by the lack of support for interactivity? I don't know what SVG "interactivity" consists of.

Does it has a stable c API?

I had to use Chrome to test it, as the viewer doesn't play on Safari.

https://thorvg.github.io/thorvg.viewer/

I'm an almost complete code novice so I was wondering if anyone can tell me if this solution would allow animations that are constructed in code rather than just play start to finish etc as a preset thing that can't be easily augmented.