Art Illusion — Optical Illusion Art | artillusion.store
An oblique anamorphosis is built by transferring a subject from a square grid onto a sheared grid, then reading it back from one fixed sight line.
Start by fixing the viewing point before any drawing happens. Mark a small dot on the desk edge or on the sheet itself where your eye will rest; every later test is made from that exact position, because oblique anamorphism forms an affine transformation of the subject and the transformation only resolves along the intended sight line.
Draw the subject on a square grid first — a letter, a star, or a simple silhouette works well. Number the rows and columns in pencil so the transfer has an unambiguous reference. Keep the subject small: an 8 × 8 cell grid is enough for a first attempt and takes about 60 minutes end to end.
Draw the receiving grid as a sheared parallelogram rather than a square. Rows stay horizontal; columns lean at a consistent angle. The shear angle and the viewing point must agree — a steeper shear needs a lower eye position, a gentler shear needs a higher one.
On narrow screens, swipe or scroll the plate sideways.
Transfer cell by cell. Copy what each square contains into the matching parallelogram cell, stretching horizontally but keeping vertical proportions. Because the transformation is affine, straight lines stay straight, so you are only relocating vertices, not re-curving edges.
Check from the marked viewpoint before inking. Slide your eye to the dot and confirm the subject reads upright. If it leans, the shear angle and sight line disagree; adjust one, not both. Once the pencil version reads correctly, erase the grid and ink the outline.
Common failures at this stage are a grid that shifts during transfer, a viewing point set too far off axis, and construction lines that do not erase cleanly. Use a 2H pencil for the grid so it lifts without scarring the paper, and re-check the viewpoint after every correction.
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