Visual Plane
every picture states the point it is correct from
Concept

Design plane — where it appears

The plane an intended picture is written on before it is carried onto a surface. Pinning it upright in front of the viewer is right for a picture on a wall and wrong for a projection with no viewer, and freeing it is what lets a design be cast along a direction rather than from a point.

Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.

no single viewpoint — the rays miss by no distance at all — the rays are parallel13 of 21 faces

A picture with no eye

The anamorph field measured which parts of an object one eye can paint, and every finding in it is about a point. A parallel projection has no such point, so the same questions have a different shape — and the two that change are the dimension of the answer and the map onto each face. The one that does not change is occlusion, which is routinely assumed away.

parallel · Noeye no single viewpoint — the rays miss by no distance at all — the rays are parallel4 pictures on 3 kinds of face

A flight that has ends

A real staircase has three families of faces and the rule proposed last round predicted three pictures. It supports four, because a picture is fixed by a direction and the flight's two sides point opposite ways — one kind of face that no single direction reaches both of. The rule counts words and the object counts orientations.

viewing · Anamorphreach

Named alongside it

The objects these essays reach for when they reach for this one.

Anamorphosiscentre of projectionCoverageFaceted objectOcclusionParallel projectionAffine mapCountingDisjoint setspoint at infinityStretchSurface normal

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