light op• Data kinds: none → rgb (an op determined by its arguments alone — it takes no image or data input)
• Call: import fullseye as fs; fs.ledger.radial_light(height, width, x, y, radius, intensity=1.0, falloff='smooth', color='emphasis', scheme='okabe_ito') (to call the implementation directly, import gfx2d; gfx2d.radial_light(height, width, x, y, radius, intensity=1.0, falloff='smooth', color='emphasis', scheme='okabe_ito'); from the registry, opsgfx2d.get("radial_light"))
A radial light map, rgb (H, W, 3), centred on (x, y).
falloff:
• "smooth" — (1 - t^2)^2, compactly supported: exactly zero at and beyond radius. The default, because a light that ends somewhere is the only kind you can budget.
• "linear" — 1 - t, also compact.
• "inverse_square" — 1 / (1 + (3t)^2), the physical law softened at the origin. Not compactly supported: it is 10 % of peak at the nominal radius and never reaches zero, so a scene full of these never gets dark.
The value at the centre is exactly intensity * color. This is a *linear-light* quantity: add lights together, then encode once.
With intensity > 1 the result leaves [0, 1] — deliberately, because a light map is not a picture. light_mask accepts it; the operators that take an rgb *image* reject it with the documented range error rather than clipping a light budget behind your back.
• 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.
• gfx2d_scene — py -3.11 examples/gfx2d_scene.py
rgb as input)srgb_to_linear · linear_to_srgb · blend_mode · light_mask · normal_map_decode · bloom · vignette · chromatic_aberration
light)light_mask · normal_map_decode · normal_map_shade · shadow_cast_2d
*Provenance: gfx2d.py — GFX2D 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.