Photogrammetry creates a three dimensional model from a set of ordinary two dimensional photographs. By taking many overlapping images of an object or scene from different angles, software can work out where each surface sits in space and rebuild it as digital geometry. It is a core part of our 3D scanning and photogrammetry service, and it solves problems that handheld hardware scanners simply cannot reach, especially on subjects that are far too big to fit on a scanning table.
The real appeal is reach and flexibility. A camera can capture a building, a vehicle, a landscape or a delicate artefact without ever touching it, and it records full colour and texture at the same time as the shape. For subjects that are large, remote or fragile, photography is often the only practical way to record true geometry, which makes photogrammetry an essential companion to contact based scanning rather than a rival to it.
The science behind the photos
When the same feature appears in several photographs taken from known positions, its location can be triangulated in three dimensions, in much the same way that two eyes judge how far away something is. The software automatically finds thousands of matching features across the entire image set and solves for all of their positions at once, recovering both the shape of the subject and where each photo was taken from.
From those matched points it builds a dense cloud and then a textured mesh that carries the real colours straight from the photographs. The accuracy of the result depends almost entirely on the quality of the input, so generous overlap between frames, sharp focus and even, consistent lighting are what separate a crisp model from a soft and unreliable one.
Where photogrammetry wins
Photogrammetry is brilliant for subjects that are too large, too remote or too fragile for a contact scanner. Building facades, terrain, large machinery in the field and museum pieces sitting behind glass are all natural candidates, because a camera can reach them when a scanning arm cannot. A drone extends that reach even further to rooftops and tall structures.
Because the camera records colour and surface texture, the finished model looks genuinely lifelike rather than a plain grey shell. That makes it ideal for visualisation, games and virtual reality, where appearance matters as much as measurement. For pure engineering accuracy on small parts, though, a dedicated scanner still has the edge, and we will say so when that is the case.
Getting good source images
The quality of a photogrammetry model depends almost entirely on the photographs that feed it, so a careful capture session is time very well spent. A handful of simple habits make the difference between a clean, measurable model and a session that has to be repeated, and we follow them on every job.
- Overlap each shot with the last by at least sixty percent.
- Keep lighting flat and consistent, avoiding hard shadows and glare.
- Hold focus sharp and keep the shutter fast enough to freeze any motion.
- Circle the subject at several heights for complete coverage.
Equipment and software in practice
You do not need exotic gear to get a strong photogrammetry result, but a few choices make a real difference. A camera with a fixed focal length lens keeps the geometry predictable, and shooting in a raw format preserves the detail the software relies on when it matches features between frames. A steady tripod, or a fast shutter when working handheld, keeps every image crisp, since even slight blur quietly weakens the final mesh and forces the software to guess.
On the processing side, the software aligns the photos, builds a dense point cloud, generates a mesh and then drapes the original colours back over it as a texture. Each of those steps takes time and computing power, so a large set of high resolution images can take hours to solve on a capable workstation. We run this work from our Perth studio and scale the photo count to the subject, capturing more frames on intricate areas and fewer on broad, simple surfaces, which keeps the project efficient without sacrificing the detail that genuinely matters.