terrain op• Data kinds: image2d × image2d → table
• Call: import fullseye as fs; fs.ledger.perlin2(x, y, seed: 'int' = 0, freq: 'float' = 1.0) -> 'dict' (to call the implementation directly, import driveterrain; driveterrain.perlin2(x, y, seed: 'int' = 0, freq: 'float' = 1.0) -> 'dict'; from the registry, opsdrive.get("perlin2"))
Evaluates Perlin's (2002, improved noise) 2-D gradient noise at world coordinates (x, y).
The lattice has a spacing of freq [periods/m], gradients are unit vectors in 8 directions, interpolation is the quintic fade 6t⁵−15t⁴+10t³. Return value {"value", "dx", "dy"} (derivatives are analytic, d/dx is per world coordinate). Theorems: value 0 at lattice points, period of 256 lattice cells, |value| ≤ 1.
• 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_world_terrain — py -3.11 examples/poc_world_terrain.py
table as input)course_layout · course_occupancy · course_contains · world_build · world_camera · world_move · lidar_scan · rss_longitudinal_same
terrain)fbm_params · fbm_height · fbm_gradient · radial_periodogram · spectral_slope · course_distance · terrain_params · terrain_height
*Provenance: driveterrain.py — DRIVE 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.