PhotoCAD Guides
A facade or interior orthophoto from Metashape, RealityCapture, or Pix4D, a rectified photograph, an orthomosaic of a floor. PhotoCAD drafts the elevation or plan as clean linework, at real scale.
A planar orthophoto of a front from Metashape, RealityCapture, RealityScan, or Pix4D, drafted as a measured elevation.
Each drawing was converted in PhotoCAD from an orthophoto or a rectified photograph. Drag the slider to compare.
Santissima Annunziata portico, Florence. Photogrammetry: E. Pellis et al., CC BY 4.0, adapted.
A photogrammetric orthophoto of a Renaissance portico. PhotoCAD draws the arches, columns, capitals, and the pedimented door, reads the inscription letter for letter, and leaves the deep shadows out.
| Method | Time | Cost | What you get |
|---|---|---|---|
| Trace it by hand | Hours per elevation | Your time | Attach the orthophoto in AutoCAD, scale it from two points, and draw every stone and opening on layers. |
| Auto-trace | Minutes, then cleanup | In AutoCAD or Illustrator | Follows pixel edges, not the building, so stains, shadows, and weathering become a tangle of lines to delete. |
| Drafting service | Days | Hundreds of dollars per elevation | A survey or drafting firm draws the elevation from your orthophoto or scan, to their standard. |
Project the model onto the plane you are drawing, the facade, the wall, or the floor, and export the orthophoto as a JPG, PNG, or TIFF, cropped to that front.
PhotoCAD converts each image at a fixed resolution, so a close crop gives every stone more detail than a whole front does. Historic England sets the largest orthophoto pixel for each drawing scale; this is the width of facade that allows in one conversion.
| Drawing scale | Facade per conversion, about | Good for |
|---|---|---|
| 1:20 (1 mm pixel) | 2.4 m | One bay, a window or door surround, stone by stone |
| 1:50 (2 mm pixel) |
Architectural photogrammetry has made the orthophoto the standard record of a building: a photograph with the perspective taken out, true to scale across a whole facade, an interior wall, or a floor. Historic England now treats it as the more accurate successor to rectified photography. But the client, the conservation officer, or the repair contractor still wants a measured drawing, and the usual way to make one is to attach the orthophoto in CAD and trace every opening, course, and stone by hand.
Tracing tools cannot do that for you: they follow pixel boundaries, so every stain, shadow, and patch of weathering becomes a line. PhotoCAD works from a semantic understanding of the image instead. It sees the architecture, the openings, moldings, string courses, and joints in the masonry, and drafts it as clean, proportionally accurate vector lines, with nothing for the stains and shadows. Set the scale from a length you surveyed, lay the drawing on a sheet at 1:50 or 1:100, and download a DWG that opens at real size: an as-built drawing for a heritage survey, a repair schedule, or a permit set.
A record drawing must show what is there and nothing else. PhotoCAD does the initial drafting; you review it against the orthophoto, where a ragged edge may have been tidied or an unclear detail misread, and correct it in CAD before you issue it.
Project onto the facade plane. A planar orthophoto keeps every opening its true shape across the whole front.
Upload an orthophoto and see PhotoCAD draft the elevation in a minute.
Your first 3 conversions are free — no card required.
An orthophoto of a wall inside, drafted as an interior elevation for a fit-out, a repair, or a conservation record.
Rectified photography, the long-standing heritage method, drafted the same way as an orthophoto.
An orthomosaic of a floor, tiles, or a mosaic, drafted as a plan of the pattern and its borders.
Diamond Street, Philadelphia. Photo: Joseph Elliott, HABS, Library of Congress.
Several attached fronts in one image. PhotoCAD draws the cornices, window bays, doors, and stoops as one continuous elevation.
Tabernacle Presbyterian Church, Philadelphia. Photo: Jack Boucher, HABS, Library of Congress.
A perspective-corrected photograph of a church front. PhotoCAD draws the tower, the tracery, the rose window, and the entrance arch.
Roman mosaic floor. The Metropolitan Museum of Art.
A mosaic floor, photographed straight down. PhotoCAD draws every border, knot, and rosette as linework, ready to set to scale.
 PhotoCAD | About a minute | ~$1 per drawing | Drafts the orthophoto as an elevation or plan: openings, moldings, and stones as clean lines, at real scale, as DWG. |
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Drop the file into PhotoCAD, up to 150 MB. One front per upload; a long facade can go bay by bay.
PhotoCAD recognizes the openings, moldings, string courses, and masonry joints and draws them as clean lines, leaving the stains and shadows out.
Click two points with a known distance between them, ideally surveyed control or the full width of the front, and type it.
Add dimensions and notes, and place the elevation on a titled sheet at 1:50 or 1:100, beside the other fronts.
Compare the drawing with the orthophoto, then open the DWG at real size, assign the linework to your layers, and add what a record needs.
3 free conversions. No card required.
| A small front, or one bay of a large one |
| 1:100 (5 mm pixel) | 12 m | A house front, a church gable |
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| 1:200 (10 mm pixel) | 24 m | A short street elevation |
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Pixel sizes from Historic England, Geospatial Survey Specifications for Cultural Heritage (HEAG317, 2024). A guide to the detail an image carries, not a statement of accuracy: check every drawing against its orthophoto.
The closer the crop, the more each stone gets. Draw a long front a bay at a time and join the bays on the sheet.
Mask the sky, scaffolding, parked cars, and the torn edge of the model before export, so they stay out of the drawing.
The full width of the front or two surveyed points, not a single brick.