typed op• Data kinds: rgbimage → rgbimage
• Call: fullseye.apply(img, "tb_wetness", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])
*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*
Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):
▸ tb_wetness: knob a sweep (docs site)
Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):
▸ tb_wetness: knob b sweep (docs site)
Stages (the ops that come before → this op, left to right):
▸ tb_wetness: stages (docs site)
On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):
▸ tb_wetness: other inputs (docs site)
Base colour of a wet surface. Diffuse darkens (and specular increases).
base_rgb: colour in the dry state, (H,W,3) or (3,). wet: degree of wetness (0–1).
ior: refractive index of the water film.
Return value: diffuse colour in the wet state (same shape).
Why it darkens: total internal reflection occurs inside the water film, so diffuse light is sent back to the surface again and again and absorbed each time. As an approximation, for the dry reflectance ρ a re-absorption equivalent to the internal reflectance Ri = 1 − (1 − Ri0)/n² is applied ―― exactly the phenomenon of wet sand looking dark (the increase in specular reflection is expressed by layering clearcoat_shade(coat=wet) on top).
The optics op wetness bridged into the 2-D evolution registry. The implementation is the same; only the calling convention is adapted to op(v, a, b). a sweeps wet (default 1) and b sweeps ior (default 1.33).
• 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 program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.
img_to_rgb 0.50 0.50 tb_wetness 0.50 0.50
▸ Load this pipeline · Load & run
The examples below call the underlying ledger op wetness. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).
• machined_metal_and_materials — py -3.11 examples/machined_metal_and_materials.py
rgbimage as input)identity · tb_sensor_capture · tb_specular_diffuse_split · tb_specular_coefficient_map · tb_specular_free_transform · tb_rgb_to_quaternion
typed)tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal · tb_voxel_grid_downsample
*Provenance: ops.py — 2D 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.