Fable's .splat4d format shrinks dynamic 3D Gaussian splats 16–58× and streams over plain HTTP Range

Fable created novel 4D splat format

Fable open-sourced .splat4d, a 4D Gaussian splat format that makes dynamic scenes 16–58× smaller than raw .splat sequences and 14–20× smaller than gzip, while encoding at ~640 MB/s. It splits static background from moving splats, stores background once, and uses H.265-style keyframes plus integer deltas for motion. A 2-second scene compresses to 7.4 MB. The format is built for HTTP Range streaming: a scrub into an unbuffered region shows a keyframe in ~145 ms. Error bounds are pointwise and deterministic—±2 mm position, ±4/255 color and opacity, exact rotation, ±2% scale. A Python encoder and a WebGPU browser viewer are available, with benchmarks across 8 sequences from three capture pipelines.

Why it matters: A new 4D Gaussian splat format with 16-58× compression and HTTP Range-native streaming, with a well-documented technical design. Useful for spatial video and real-time rendering folks, but the audience is narrow — not industry-shaking. H and K both hit, R is weak, lands right ...