← artdaily

Cube From Plane

grow the face into a correct cube

round
–
score
–
best
–

Loading…

Growing one face into a whole box

The sheet shows a horizon and one vertical face of a cube. Three numbered dots are yours — 1 far-bottom, 2 far-top, 3 top-back — to drag until all nine visible edges converge; then press done. Three boxes per round (two on a first-ever round, so the first score arrives in about a minute), the right-hand vanishing point pulling in further each box. The dots start 25–33% of the face diagonal off the truth, so pressing done without moving anything cannot clear 30 on any hardware.

The habit being replaced is placing corners; the habit being built is aiming edges at vanishing points. The word arrives before the drill leans on it: while the dots are still live, faint dashed lines carry the drawn face's two horizontal edges out to the left vanishing point, tagged these edges aim here. Underneath, the truth is an actual unit cube through a real pinhole camera — the 90° constraint ties the pair of vanishing points to the focal length, so the square face you were handed secretly fixes both.

What each dot costs you

Per corner, the error is the distance from your dot to the true corner over the face diagonal; a box scores 100 · clamp(1 − mean(err)/0.30, 0, 1) with a perfect zone around the truth so 100 is reachable, and the round is the mean of the boxes. That zone belongs to the hardware: 1.5% of the face diagonal is the pen standard, opened ×2 for a mouse or trackpad and ×1.5 for a finger, then floored at 4 eased pixels, 9 on a coarse screen — 1.5% of a 140px phone face was a 2.1px target, under the device's own noise. The 0.30 ramp is identical everywhere, because that part is judgement, not hardware. Nothing is judged by a model — the mark is that comparison of your three dots against corners the camera fixed before you touched them.

More form & perspective drills: Box Check · Vanishing Point Hunt · Rotate & Place · the whole catalogue