Impossible Trident / Blivet
The classic Blivet: three cylindrical prongs at one end become two rectangular arms at the other. Follow the six contours to see solid material turn into empty space.
Click the visible surface to select a piece; drag to move it. Labelled handles resize along the solid’s own axes; the green handle rotates. Hold Shift to bypass snapping, or Alt to move a piece apart from its joints.
Keyboard: arrows move; Shift+arrows move by 10 px; Delete removes; Ctrl+D duplicates; Ctrl+Z / Ctrl+Shift+Z undo and redo.
Click joints to build connected lines. Drag a yellow midpoint to curve a segment; drag a blue joint to reshape adjacent segments. Enter or double-click finishes. Click the first joint to close a path. Shift snaps new points to the grid.
Tip: crisp, connected lines give the clearest clues. Nothing is uploaded to a server.
Reconstruct and inspect in 3D
Inspect closed solid pieces with their exact dimensions, shared vertices and 3D connection equations. Uploads fit visible piece silhouettes; unsupported pictures use surface boundaries. Partial versions omit conflicting pieces or surfaces; possible versions leave incompatible joins disconnected. Your image stays on your device.
AnonMoos, Poiuyt.svg, Wikimedia Commons, public domain. Uniformly scaled and recoloured; the original contours are preserved.
Inspect the pieces and their connections
Cover the round ends: the remaining contours read as two rectangular arms. Cover the handle: the same contours read as three cylindrical prongs.
An edge that bounds solid material at one end bounds empty space at the other. The classic drawing cannot keep a consistent assignment of surfaces along all six rails.
This is the classic contour drawing, with its three round ends and two rectangular arms. The unedited example is identified as a known impossible reference. Adding or changing lines switches to drawing analysis; it does not inherit the reference verdict.
Read the Impossible Trident / Blivet drawing guide, then try your own construction in the impossible shapes detector. The reconstruction method explains how solid dimensions, image fitting and connection equations contribute different evidence.
Compare the source view with a rotating model
This contour changes the number of prongs as you trace it. Its visible lines do not define solid pieces with reliable thickness, so reconstruction preserves the drawing instead of inventing a connected model. Share, PNG and PDF preserve a result locally.
Raster uploads are fitted from their visible silhouette and colour regions. A recognized complete construction supplies its intended connection rules only after the pixel fit succeeds. Separate fitted primitives remain separate. An unfamiliar picture can leave hidden structure unresolved; see how to inspect an ambiguous drawing.
Compare Tribox — Impossible Square, Impossible Hexagon — Beam Study and Impossible Ladder — Frame Study to examine how different piece arrangements change the joints and openings.
For further editing experiments, open Tribox — Impossible Square, Impossible Hexagon — Beam Study or Impossible Window — Frame Study and compare their closure equations after detaching a connection.