stimulus op• Data kinds: table → signal
• Call: import fullseye as fs; fs.ledger.fly_view_plane_texture(lattice, distance_m, period_m, pattern='vertical', drho_deg=8.23, contrast=1.0, mean=0.5, lateral_m=(0.0, 0.0), phase_deg=0.0) (to call the implementation directly, import flyvision; flyvision.fly_view_plane_texture(lattice, distance_m, period_m, pattern='vertical', drho_deg=8.23, contrast=1.0, mean=0.5, lateral_m=(0.0, 0.0), phase_deg=0.0); from the registry, opsflyvision.get("fly_view_plane_texture"))
What each ommatidium sees of a periodic frontal surface — integrated analytically.
A plane at *distance_m* ahead of the eye (x = distance_m in body coordinates, texture in (y, z)) carries a reflectance mean * (1 + contrast * s(y, z)) with s in [-1, 1]: stripes of period *period_m* ("vertical" modulates along y, "horizontal" along z), a "checker" of that period, a pure "sine", a deterministic 1/f "pink" texture whose longest wavelength is *period_m* (24 plane waves with amplitudes summing to 1, so its rms contrast is 0.18 of *contrast*), or "grey". Each ommatidium integrates the surface under a Gaussian acceptance of FWHM *drho_deg* — without rendering or resampling an image. The texture is a cosine series; a surface wave vector k becomes the angular wave vector J^T k at the ommatidium (J the exact derivative of the line-of-sight intercept), and a Gaussian acceptance multiplies each term by exp(-pi^2 drho^2 |J^T k|^2 / (4 ln2)). That is the small-footprint
approximation fly_hex_resample documents, applied term by term, with no pixel grid in between.
lattice: a fly_hex_lattice or fly_vogel_lattice result.
distance_m / period_m: the plane's distance and the texture period, metres.
pattern: one of PLANE_PATTERNS.
drho_deg: the acceptance FWHM, degrees.
contrast: the Michelson contrast of the texture, 0 <= contrast <= 1.
mean: the mean reflectance (> 0).
lateral_m: the eye's (y, z) offset from the texture origin, metres — the
fly's sideways position, which shifts the stripe phase.
phase_deg: an extra texture shift, in degrees of one period.
Returns a 1-D float64 signal of n ommatidial intensities (>= 0). An ommatidium whose line of sight does not reach the plane (d_x <= 0) reads *mean* — the surface is not in its field, and a texture at an infinite distance has zero modulation anyway.
Square waves keep their odd harmonics up to where the acceptance has attenuated them below 1e-6 (at most MAX_HARMONIC); a checkerboard is the product of two such series. The partial sum is then already smoothed, so there is no Gibbs overshoot to clip; a maximum(., 0) guards rounding.
Ground truth (pinned in the tests): for pattern="sine" the amplitude at the central ommatidium is contrast * mean * exp(-pi^2 drho^2 (D/P)^2 / (4 ln2)) with drho in radians, and at an ommatidium at azimuth theta the angular frequency is D/(P cos^2 theta) — both to 1e-9.
Raises ValueError: a malformed *lattice* (an empty dict is refused — it has none of the lattice keys), a non-positive *distance_m* / *period_m* / *drho_deg* / *mean*, a *contrast* outside [0, 1], a *lateral_m* that is not two finite numbers, a non-finite *phase_deg*, and an unknown *pattern*.
• 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.
• poc_zebra_stripes_fly_eye — py -3.11 examples/poc_zebra_stripes_fly_eye.py
signal as input)fly_hex_quantize · fly_emd_response · fly_lgmd_eta · fly_tau_from_expansion · lattice_moire_peak · traj_tau_dot · fly_dsi
stimulus)*Provenance: flyvision.py — FLYVISION 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.