Tangent — the glancing-contact drill

Drag the base handle

You do not aim the tip. You drag the base plate; a two-bone arm carries the tip toward a small surface. A hidden spot on that surface, and a hidden glancing angle, both score you. Dead-on, perpendicular hits overshoot and score negative — the reward is off-axis, tangential contact at a consistent shallow angle. Left-drag the plate (forgiving grab) · right-drag or hold Space to orbit · wheel zooms.

Incidence vs surface

— pick a target —

Score 0

left-drag the pink plate (forgiving grab) · right-drag / Space+drag to orbit · wheel zoom · the sweet spot and angle are hidden — read the strip

press New target to begin

Contact state: idle

Not in band
hold inside the glancing band to lock

0LOCKS

0OVERSHOOTS

—BEST SCORE

—LAST LOCK

Press New target. A hidden sweet spot and glancing angle appear on the surface. Drag the base plate until the strip reads warm — then hold steady to lock.

Why did I miss?

Error is split so a miss is legible — is your incidence wrong (too direct / too shallow), or your placement wrong (tip vs the spot on the surface)?

Assists & options

Reveal sweet spot & band (training wheels)

Show tip vector Show linkage

Show glancing band ring (on approach)

Keyboard controls

Click the 3D view first (it takes focus). ←→↑↓ orbit · Home reset view · wheel zoom.
Drag the pink base plate to drive the arm. The tip is the referent of all feedback — always.

What this drill teaches

One sub-skill only: indirect / glancing contact. The target is a small surface with a hidden position (the sweet spot) and scoring is dominated by the angle of incidence the tip strikes it at. A near-perpendicular, dead-center hit is not the goal — it overshoots and scores negative, modeling over-sensitivity from too much direct pressure. The reward zone is a ring of shallow, tangential incidence angles: too steep (near-perpendicular) overshoots, too shallow (nearly parallel) misses entirely, and a mid-band glancing angle is the sweet spot. Feedback is always tip-referenced — the strip reads the tip's incidence and contact point against the surface, never your drag input directly. Max two uncertainty sources: hidden target (spot + angle) + indirect linkage. Randomized per attempt, static within the attempt — no drift here.