volseq_synth_beating — LIVE4D synth op

• Data kinds: none → volseq (an op determined by its arguments alone — it takes no image or data input)

• Call: import fullseye as fs; fs.ledger.volseq_synth_beating(shape=(24, 32, 32), n_frames: 'int' = 24, period: 'float' = 12.0, amplitude: 'float' = 2.0, radius: 'float' = 8.0, thickness: 'float' = 1.5, noise: 'float' = 0.0, seed: 'int' = 0) -> 'np.ndarray' (to call the implementation directly, import live4d; live4d.volseq_synth_beating(shape=(24, 32, 32), n_frames: 'int' = 24, period: 'float' = 12.0, amplitude: 'float' = 2.0, radius: 'float' = 8.0, thickness: 'float' = 1.5, noise: 'float' = 0.0, seed: 'int' = 0) -> 'np.ndarray'; from the registry, opslive4d.get("volseq_synth_beating"))

Usage

Volume time series (T, Z, Y, X) of a shell pulsating according to a known radius law (volseq, values in [0, 1] + noise).

The radius is r(t) = radius + amplitude · sin(2π t / period) (t is the frame number), and the shell is exp(−(d − r(t))² / (2 · thickness²)) as a function of the distance d from the centre. A minimal model of beating heart muscle or a contracting cell; since ground truth = the radius law itself, the amplification, interpolation and rendering ops can each be verified numerically by "reading off the radius". With noise > 0, Gaussian noise (standard deviation) is added (reproducible with seed).

>>> s = volseq_synth_beating((16, 24, 24), n_frames=12, period=12.0, amplitude=1.0)

>>> s.shape

(12, 16, 24, 24)

Detailed usage guide

• live4d family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• poc_live4d — py -3.11 examples/poc_live4d.py

Ops the type connects to (they accept volseq as input)

volseq_mip_video · volseq_cut_video · volseq_speed · volseq_pathline_render · volseq_pathline_orbit · volseq_interpolate_flow · volseq_magnify_motion · volseq_render_orbit

Same category (synth)

volseq_synth_dividing

*Provenance: live4d.py — LIVE4D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.