Reality Capture

Reality capture

Creating realistic, virtual representations of buildings or sites by means of laser point clouds (LiDAR technology) and/or photos from multiple angles (photogrammetry). Reality Capture models may also be geotagged, BIM compatible and photorealistic.

Reality capture is the process of creating virtual 3D models of real world objects (e.g. buildings or sites) by scanning and/or photographing the object from multiple angles. The data is typically captured by means of laser 3D scanners or cameras, which are either handheld, terrestrial or attached to a vehicle or drone.

Laser 3D scanning technology (also known as LiDAR) uses laser beams to collect data about the distance to points on surfaces within its field of view. This data is used to produce 3D point clouds.

Another reality capture technology is called photogrammetry. This refers to the analysis of multiple photos of an object to obtain data about e.g. distances and colours of the object.

Depending on the task, construction companies may use 3D laser point clouds and photogrammetry – sometimes in combination with GPS data or BIM models – to create a photorealistic virtual 3D model of buildings or sites.

Benefits and challenges

  • Quick way to analyse the conditions on site before, under and after construction projects
  • Improved accuracy of 3D models and the ability to measure change over time
  • Improved communication between construction stakeholders due to realistic 3D visualisations
  • Lower time and cost of capturing on-site conditions due to automation in data collection and processing
  • Need for large data processing capability

Application examples

In the U.S, reality capture technologies has been used to create a detailed digital 3D model of the Glen Canyon Dam in Arizona in 2016. The Bureau of Reclamation commissioned the software developer Autodesk to supplement the 1963 paper plans of the dam with a digital model to make it easier to assess the dam’s conditions and the effects of aging, weather and water flow changes. Autodesk used LiDAR, sonar and cameras to capture a very large amount of data on the massive site from land, water and air (www.autodesk.com).  

The technology developer SKUR offers reality capture solutions that compares the as-built conditions to the design models. These solutions allow the general contractor to verify the construction and identify areas of variance on-site where corrective action is needed (skur.com). 

Development stage

Reality capture technologies are mature and readily available in construction. 

Construction impact

Reality Capture technologies are expected to affect the following phases of construction projects: 

  • The design phase: Capturing on-site reality
  • The construction phase: Comparing as-built to design models.
  • The operational phase: Inspecting maintenance needs

References

connect.bim360.autodesk.com

www.aecnext.com

www.engineering.com

www.getrevue.co

http://www.technologycards.net/the-technologies/reality-capture
21 AUGUST 2019