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Comment by simonw | Hacker News Reader

I didn't want to shell out for Max again, so I piped the SVG created by Max back into Fable 5.1 at its default thinking level (of high):

  llm logs -cx | llm -m claude-fable-5.1 -s 'animate this'

Here's the result, which cost $1.37: https://tools.simonwillison.net/markdown-svg-renderer?url=ht...

It's excellent!

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First time this benchmark impressed me - 10/10 I would believe a human spent hours making this. There are details a human would have done better (beak attaching to the head) but still impressive.

I like how precise it got about the math behind the chain/gear/wheel/leg movement... these are the details that ain't no one really got time for.

Well, the wheels are rotating the wrong way, but other than that!

(Maybe it's a strobing artifact?)

I looked closely. They are going the wrong way. Still the best one I've seen by a lot.

Probably some temporal aliasing on your device. The SVG elements are 100% rotating clockwise.

Still a flaw--the SVG should account for how different client devices will render it! Existential doom averted, for now.

Let me know when AI patches this bug in the wheels on all the vehicles on the highway, AND my box fan when it's next to the light with the bad PWM dimming. Then we can resume our existential doom.

Looks fine on safari iPadOS 26.6.1 wheels rotating forwards. I’m a skeptic but man, this actually has me revising my opinion a bit.

Are they? Looked correct to me. At high enough speeds even real ones can look rotating either way in videos depending on fps.

This is an optical illusion. If I stare at it and mentally expect a direction, I can make the wheels appear to turn either way.

I find it interesting that you put the instruction ("animate this") in the system prompt, while the prompt just had the existing SVG and no actual instructions on what to do with it. Anthropic's consumer-facing tools generally don't let you do this, unless maybe you're particularly clever with Claude Code command line flags (you can start Claude Code with a custom system prompt).

Do you think this had a substantial effect on the output?

You can do it with the Claude cli. You can pipe into it like that and set system prompt

Sorry, yes, that's what I meant by being "clever with Claude Code command line flags", I guess it's not really that clever. But in general if you just launch Claude Code normally and use it via the interactive CLI, you can't change the system prompt, so most users probably never do it.

He looks very happy riding along the beach. I love the basket fish animation as well. Impressive!

Dang the little fish jiggling around the basket is a nice touch

Not sure if it's a rendering artefact, but the wheels are spinning backwards for me?

Also, 10 tooth sprocket with 22 tooth chainring? Not impossible, but so small!

How can you tell which way are they spinning? The constant fps acts as a shutter.

Now that it's a solved benchmark, can we get the 3d animated version?

I can't waste Fable for play time, but I was curius, so I used plain claude.ai with Opus 5 High. It's pretty cool.

I asked "create a 3d animation", and pasted the Simon’s animation code.

I must admit I used a second prompt to adjust the opening camera angle, but that is all. Originally the camera was above, about 30 degrees.

https://claude.ai/public/artifacts/b37a9ee2-f5bc-4ff9-ae90-a...

That's seriously impressive.

I have to admit, these are not directly comparable to Simon's tests though, as I was using claude.ai, and he is using raw API correct?

I suppose I could use Claude Code, and disable system prompts. That should be the same, right?

If I have spare tokens at the end of the week, I will try real tests.

I couldn't help myself. Here is the game, one-shot on claude.ai, Opus 5 Extra. There could certainly be play-ability improvements made with 1 or 2 prompts, but neato for one-shot.

"Create a fun and cool game from this" - and pasted the code from above.

https://claude.ai/public/artifacts/e723244b-fa52-4e63-9819-4...

If anyone has the spare Fable tokens, would love to see the difference in the 3D animation and maybe even game.

Jesus. It's not the world's greatest game, but still. What a world we live in now.

No feet lol (also it's not animated for me)

Same happened to me (the feet are on the top left corner, brw). But the generated MP4 works.

I see both feet and animation.

For me it worked on Chrome but not on Firefox

For me:

Firefox: No feet, no animation

Chrome: Feet included, animated very nicely (uses significant CPU)

What browser are you using that doesn't have feet (or animations)? Seems to all be there in Chrome.

Firefox

And no pedals, also no animation on Firefox.

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