July 4, 2026

Splats, stats, and side-eyes

Fable created novel 4D splat format

Tiny 3D video files wow fans, but the comments instantly turned into a fact-check fight

TLDR: Fable unveiled a new way to pack moving 3D scenes into much smaller files that can stream in a browser, which could make interactive 3D far easier to share. Commenters were split between being genuinely impressed and immediately grilling the demo’s speed claims and device support.

Fable dropped a new file format that promises something very internet-catnip: huge 3D scenes shrunk down to a tiny, streamable size. The flashy demo claims a 2-second moving scene can fit into a 7.4 MB file instead of a whopping 427 MB raw version, while still letting people scrub around in the browser almost instantly. In plain English: it’s trying to make rich, moving 3D captures behave more like clicking around a website than downloading a giant monster file first. That alone had commenters doing the classic tech-forum double take: “wow… this is seriously cool.”

But of course, no shiny launch survives first contact with the comments. The biggest drama came from people side-eyeing the numbers. One commenter basically hit the brakes and said, hold on, “Something’s way off with these numbers.” The confusion centered on the claim that it encodes at 640 MB per second, which sounded enormous next to the tiny demo file size. Was that the speed of making the file, the speed of playback, or just awkward wording? Suddenly the thread had that deliciously familiar vibe: half amazed, half squinting at the benchmark chart like it owes them money.

Then came the universal buzzkill of every web demo launch: it doesn’t work on my device. One user flatly reported that iOS Safari was a no-go, instantly giving the hype train a tiny flat tire. Meanwhile, the creator kept it chill, linking the demo and inviting contributions under an MIT open-source license. So the mood is clear: people love the idea, but they want the receipts.

Key Points

  • The article presents .splat4d as a 4D Gaussian splat format for dynamic scenes with tunable, deterministic error bounds and HTTP Range-native streaming.
  • It claims compression of 16–58× versus raw data and 14–20× versus gzip, with a demo showing a 2-second scene stored as 7.4 MB instead of 427 MB of raw .splat frames.
  • The codec separates static splats from dynamic splats, stores static content once, and uses keyframes plus exact integer delta P-frames in independently decodable GOP chunks.
  • The file format includes a header with absolute byte ranges, a static section for immediate first-view rendering, and GOP chunks with key streams placed before delta streams for fast seeking.
  • The article says reconstruction is guaranteed within user-set bounds for each attribute, using SZ/ZFP-style quantization, integer math, and bit-identical Rust and JavaScript decoders.

Hottest takes

“Something’s way off with these numbers” — gcr
“Doesn’t with for me, iOS Safari :/” — Lucasoato
“wow… this is seriously cool.” — mistahchris
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