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A perspective grid to draw over, laid out on a real sheet — Letter to ARCH E, the 36″ square, an iPad screen — and built as a real construction rather than a decorative fan of lines. Pick the system: ONE-POINT (the room you face, its back wall on the picture plane), TWO-POINT (the corner you turn), THREE-POINT (the camera tilts), FOUR-POINT (a 360° cylinder unrolled, four points on the horizon) or FIVE-POINT (the hemisphere, every straight line a compass arc). Set the eye height, the viewing distance, the architect's scale that is true on the picture plane, the grid's turn and the pitch, and a measured room or corner is projected onto the sheet with its horizon, ground line, vanishing points, measuring points, distance points, the 60° cone of vision and the construction that proves them — the station point folded down on its semicircle, the swing to the measuring points, the true-height line. Drag any point and the camera is solved back from it (the CV is the orthocentre in three-point). Every point says how it was found on hover; a lesson beside the sheet says what the system is, what to check and where it breaks. Exports a true-size PDF to print under trace, a layered SVG for Illustrator, and a transparent PNG to drop into Morpholio Trace or Procreate as an underlay. Client-side; nothing uploaded.

in
Method: The guide lines are clipped to the sheet inside this border.
ft
Method: The horizon IS eye level: the ground line sits eye height × scale below it. 5′-6″ is a standing adult; 4′-0″ a seated one; 2′-0″ a child's view.
ft
Method: How far your eye stands from the picture plane. On the sheet it is d = distance × scale; the station point is d below the CV, the cone of vision has radius d·tan 30°, and the vanishing points move apart as it grows.
Method: The architect's scale that is true ON the picture plane (the ground line, the true-height line, the one-point back wall). Everywhere else the perspective has no scale.
°
Method: The angle between the grid's first family and the picture plane. VPL sits d′·cot α left of the CV and VPR d′·tan α right of it; 45° puts them symmetric at ±d′.
in
Method: Where the horizon line sits on the sheet, from the bottom edge. It does not change the camera — it moves the window on the picture plane. Low horizons look up at a room; high ones look down into it.
in
Method: Where straight-ahead lands, from the sheet's left edge. Off-centre is normal — a view framed to one side — as long as the sheet's corners stay inside the cone.
Method: The grid's module in the world. On the ground line one unit is unit × scale inches, true size.
ft
Method: How high the wall grids rise. On the true-height line a foot is one scale-foot; elsewhere the construction carries it.
units
Method: How many grid units the ground runs from the corner (or the back wall). A long run packs lines toward the horizon; a short one keeps the sheet clean.

A post as tall as your eye at each grid line — every top lands on the horizon.

Station point, semicircle, measuring points and lines, the true-height line.

pt
Method: The grid's line weight on the exported sheet, in points. The horizon and sheet edge are heavier, the construction lighter, in fixed ratios.
Two-point · 36 × 24VPL 13.18 in off the left edge · VPR 28.39 in from the left
Two-point perspective guide grid on a 36 by 24 inch sheet. Horizon 12 inches from the bottom, eye height 5′-6″, grid unit 2′-0″. Vanishing points 31.18 inches left and 10.39 inches right of the centre of vision; the grid is turned 30 degrees to the picture plane and seen from 36′-0″ away. Two wall planes meet at the corner and rise 10′-0″.HLGLCVVPRMPLMPRTwo-point perspective underlay · eye 5′-6″ · viewing distance 36′-0″ · ½″ = 1′-0″ on the picture plane · grid 2′-0″ · grid turned 30° / 60° · 36 × 24 in

Read the construction

5′-6″
36′-0″
½″ = 1′-0″
18 in
13.18 in off the left edge
28.39 in from the left
22.82 in from the left · 7.61 in from the left
30° / 60°
1 in

The sheet's far corner sits 48° off the view axis — outside the 60° cone. The grid will stretch toward it; stand farther back (a longer viewing distance) or use a smaller sheet.

Plan — folded down

picture planeSP (eye)CV60° coneVPLVPRα = 30°d

The lesson

Two-point — the corner you turn

Two families of level lines recede to two vanishing points on the horizon; verticals stay vertical because the camera is level.

The camera

The camera is level, but the building is turned to it: its two sets of walls meet the picture plane at α and 90° − α. The corner stands on the picture plane, so the vertical edge at the corner is the true-height line — the one place a height can be measured with a scale.

The points

  • VPL and VPR — where the two families meet the horizon. They are not free: seen from the station point they subtend a right angle, so SP sits on the semicircle whose diameter is VPL–VPR. Pull them apart and the viewing distance grows (d′² = CV→VPL × CV→VPR).
  • CV — the centre of vision, where the perpendicular from your eye meets the picture plane; the cone of vision is centred on it. In two-point it lies on the horizon.
  • MPL and MPR — the measuring points. Swing the station point onto the horizon about each vanishing point. A true length marked on the ground line and joined to the measuring point cuts the receding line at that depth; that is how the grid's divisions were found, and how you measure any dimension off the sheet.
  • The 45° diagonals' points (dashed) are the two families' bisectors; with α = 45° they fall at the distance points, as in one-point.

Check it on the sheet

Drag VPL toward the centre: VPR races away and the corner opens out — a near, acute view. Drag it away: the two points close toward symmetric, the station point drops and the view calms. The semicircle never breaks.

Draw this one for

Exterior corners and building masses; interiors looking into a corner; the default architectural perspective.

Where it breaks

Vanishing points off the sheet are normal — the tool tells you where they are — but a grid that needs them inside a small sheet is a camera standing too close. Check the cone: the sheet's corners should sit inside 30° of the centre of vision.
Underlay · Good Tools