Spray path planner — grading, deposition and robot targets

Spray path planner

Fixed nozzle, robot moves the last. The path is one continuous spiral of lines tweened between the two edges of the upper (collar and sole bite line): closer together where the upper is short, wider where it is long. Robot speed evens out the summed layer, in every size.

Graded last→Tween field→Spiral→Deposition→Speed→Robot poses

Size

Nozzle spray width

Max line spacing (coverage limit)

Speed compensation Toolpath Brand zone

How it works

Graded last — your foot-form mesh is US 10; other sizes: length +8.46 mm, girth +2% per size (assumed grade rule).
Tween field — u = d_collar / (d_collar + d_sole) from two geodesic distance fields (heat method). u runs from 0 on the collar to 1 on the bite line, so its iso-lines blend one edge into the other. The field is then smoothed (12 mm) so the lines round the crease on top of the forefoot instead of kinking there.
Spiral — one curve: the level set of turns·u − θ/2π, plus a closed loop along each edge. The widest spot sets the number of turns (line spacing there ≤ the coverage limit); everywhere else the lines are closer.
Deposition — each stretch of path lays a footprint as wide as the nozzle; the layer is the sum of all overlaps.
Speed — closer lines would mean a thicker layer, so the planner solves a robot speed for every point (40–250% of nominal, smoothed) until the summed layer is uniform.
Robot poses — for every point the last is posed so the point sits at stand-off under the fixed nozzle, normal facing it; checked against the spray-head envelope and exported with time and feed rate.

Why scaling fails: a scaled program keeps turns and speeds of US 10, so the layer gets thicker and heavier in small sizes and thinner in big ones. Regenerating changes the number of turns and the speed profile per size.

Every step is a pure function with no UI dependency: the same core runs here, headless for batch grading, and in tests. Simplified deposition model and assumed process values; no On data.

Drag to orbit · scroll to zoom

Each pass is a translucent ribbon as wide as the nozzle. Where ribbons overlap the tint stacks up; a slower pass lays a stronger ribbon.

bare1 pass234

Path colour = robot speed: slower · nominal · faster

Computing…

Batch grading — all sizes (US 10 program scaled vs regenerated)

Size (US)	Last mm	Turns	Path m	Cycle s	Scaled: mean layer	Scaled: within ±10%	Regen: mean layer	Regen: within ±10%