Hand: A Figure in Miniature

"Every artist has a drawer of drawings with the hands hidden in pockets. The hand is the boss fight, and the construction is the strategy."

The Hardest Thing to Draw

Hands are the thing beginners hide and professionals respect. The reason is pure density: fifteen finger-bone segments plus the palm, each a small volume, all articulating independently, and half of them usually pointing toward or away from you at once. A hand is a whole figure compressed into a fist-sized space — more joints per square inch than anything else you'll draw. Which means it needs exactly what the figure needed, just more of it: construction.

Palm Box and Phalanx Frustums

The hand construction reuses the figure's logic at small scale. A palm box establishes the mass and the plane of the hand — the single most-skipped step, and the one that makes everything after it land. Then each of the fifteen phalanges (finger-bone segments) is built as a tapered frustum, a little truncated cone anchored to the detected joints. Box for the mass, frustums for the segments: it is the identical construction you met on the figure's ribcage and limbs, which is the whole point — the hand isn't a new problem, it's the figure problem at higher density.

The Pad Sweep

Getting there requires reliably finding the hand first. Detection uses a pad sweep — scanning the image for the hand rather than assuming where it sits — and returns 21 landmark points. Those points are, once again, only a proposal: the geometry that wraps a palm box and phalanx frustums around them is deterministic. The hand is the same propose-then-construct architecture as every other subject, just with a detector tuned for a small, self-occluding, endlessly-posed shape.

Per-Phalanx Foreshortening

The construction reports foreshortening for each phalanx, and this is where it earns its keep. A finger curled toward the camera is almost entirely foreshortening — a stack of compressed disks your eye desperately wants to draw as full-length. Naming the compression segment by segment turns the single hardest perceptual call in hand drawing into an explicit number you can check. The hand construction, like the figure and the portrait before it, is the engine pointing a spotlight at exactly the thing you can't yet trust your eye to see.

Code

Hand construction: pad sweep, palm box, phalanx frustums·python

# Hand: 21 landmarks via a pad sweep, then the SAME box+frustum logic as the figure.
hand_pts  = detect_hand(photo)             # 21 points, pad-sweep detection
palm      = palm_box(hand_pts)             # the mass and plane of the hand -- FIRST
phalanges = [taper_frustum(a, b)           # 15 finger-bone segments as volumes
             for a, b in phalanx_segments(hand_pts)]

# Per-phalanx foreshortening: a finger pointing at you is almost ALL compression.
readout = {p.name: foreshortening(p) for p in phalanges}

hand = apply_exaggeration(palm, phalanges, k=hand_exaggeration)
# Box for mass, frustum for each segment -- the figure's construction, densified.

Exercise

Hold your own hand up pointing roughly at your eye, so the fingers are heavily foreshortened. Draw it — but force yourself to build each finger as a stack of two or three short cylinders, and the palm as a box, before any outline. Notice how the construction makes you confront the compression you'd otherwise draw away. Then compare it to a quick outline-only attempt of the same view.

Hint

The outline attempt will quietly lengthen the foreshortened fingers, because a line has no way to admit it's pointing at you. The cylinder-stack forces each segment to declare its compression, which is exactly the per-phalanx foreshortening the engine reports. Hands get easier the moment you stop drawing their edges and start stacking their volumes.