Reality Capture (Laser Scanning & Point Clouds)
Using laser scanners or photogrammetry to capture a highly accurate, three-dimensional "point cloud" of existing physical conditions, such as a site, a structure, or an already-built space, that can be compared directly against design drawings or a [[concept-bim|BIM]] model.
Why it matters
Existing conditions on a renovation project rarely match the original drawings exactly, after years of undocumented changes. Reality capture replaces guesswork about what's actually there with a precise, measurable record, which matters most on renovation and retrofit work where the design has to fit around what already exists.
On a real project
Before designing a building renovation, a survey team laser-scans the existing structure and produces a point cloud that reveals the actual floor-to-floor heights are two inches different from the original drawings, a discrepancy the design team accounts for before finalizing new ceiling and mechanical layouts.
Who this matters most to
A Surveyor increasingly uses laser scanning alongside traditional survey equipment to capture existing conditions with a level of detail conventional methods can't match. A Drone/UAV Specialist captures the same kind of point cloud data from the air for a site's exterior and topography, using photogrammetry instead of ground-based scanning.
Where this goes wrong
A renovation project designs against the original drawings without verifying existing conditions with a reality capture scan, assuming decades-old drawings are still accurate. Field crews discover a significant discrepancy once demolition begins, forcing a design change mid-construction that a pre-design scan would have caught.