Structured vs. Unified & Unstructured Scan Data

Terrestrial or Static Laser Scanning

Each individual scan comes with its depth map, associating X, Y, Z data to each pixel of the panoramic image grid.

Structured Scans

• The structured data contains each scan location, each panoramic image & depth map, and the 3D point cloud, as the result from the registration process.
• Each scan location is visible in the 3D space.
• It’s possible to be in each scan position, see the panoramic image and navigate from scan to scan.
• File size for each scan is big.

Scan view from one scan Position

Unified Scans

• Unified scans lose the ‘structure’ of the project.
• Scan positions are no more visible in the 3D view.
• Panoramic images are lost.
• Navigation from scan to scan is no more possible.
• The quality of the scan project is affected.
• Overall file size is slightly smaller, making the 3D point cloud somehow easier to consume in desktop modeling apps such as Revit for example.

3D View—Scan Positions are no longer visible

Unstructured point clouds are generated from:

• Mobile Lidars
• Drone-based photogrammetry
  • This data is ‘unstructured’ since there are no scan positions associated to a depth map as produced with laser scanners on a tripod.
  • It’s pretty similar to a ‘unified’ point cloud.

Structured scan file formats

• (Structured) RCP: the native format for Autodesk ReCap projects
• (Structured) FLS: the native format for Faro Scene projects
• (Structured) E57: the standard exchange format for terrestrial laser scanning
• Every point cloud software provides the option to export a structured E57 file.
  • Faro Scene, Trimble RealWorks, Leica Cyclone, Topcon ScanMaster…
  • To know how to generate a structured E57 from these software, please ask us at: [email protected]
    • There are other structured scan formats generated by point cloud software: FLS, PTX, TZF…

Structured-to-unified is possible.

• Every point cloud software provides the option to generate a unified point cloud.
• Turning a structured point cloud into a unified point cloud is a destructive operation though since the structure of the scan data is lost and the overall quality is affected.
• Typically, 2 formats are used:
  • Unified RCS, making your scan data directly consumable by all Autodesk desktop apps.
  • Unified E57

Unified-to-structured is impossible.

• Once the scan data has been unified, all the ‘structure’ data of the project is lost, making it impossible to recover it.