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3D Laser Scanning
10/14/2015 1
What is 3D Laser Scanning?
• A 3D scanner is a device that analyses a real‐world object or environment to collect data on its shape and possibly its appearance.
• The collected data can then be used to construct digital three‐dimensional models.
• 3D scanning and spatial data acquisition has become the standard behind accurate scene management and evidence collection.
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3D Laser Scanning at CASE• Captures critical scene information before the scene is
disturbed, evidence moved, restoration efforts begun, etc.– You may not get a second chance!
• Gathers large volumes of data very quickly– Large scene scans in under an hour – Millions of data points
• Full color photographs in addition to point cloud data• Capable of capturing large scale scenes
– Fires/Explosions– Natural Disasters/CAT events
• “Sees” difficult to access spaces– Underneath a bridge– Underneath a collapsed section of a building
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3D Laser Scanning at CASE• What can you do with the data?
– Visualize entire scene• Video• Photographs
– Converted to 2D and 3D models– Create 2D floor plans– Create Trial Documents– Create Fly‐throughs– Use scanner generated photographs for small items, in conjunction with photogrammetry to see minute details.
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CASE STUDY3D Laser Scanning
Grist Mill 3D Laser Scan Generated Photos
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Grist Mill 3D Laser Scan Generated Photos
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Grist Mill 3D Laser Scan Generated Photos
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Grist Mill 3D Laser Scan Generated Photos
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Grist Mill 3D Laser Scan Generated Photos
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3D Photogrammetry Modeling
• 3D spatial data extracted from digital images – Data can be utilized for
• Visualizations• Mapping• Digital preservation• Reconstruction• Anything else that would benefit from information acquisition beyond standard photos and drawings
3D Photogrammetry• Ability to capture data on‐the‐fly • A backup, and alternative to 3D Scanning
– Sometimes though, because of small size or surface material, laser scanning is not possible. Photogrammetry is a great way to augment the scan data.
– Even if you have a laser scanner at your disposal, the need for 3D visualization may not be initially apparent, the scanner isn’t logistically available, or the site conditions are not optimal for a laser scanner.
– By capturing the subject with a camera or even a smart phone, the site, or evidence can still be developed into interactive models.
3D Photogrammetry Evidence Visualizations• Accurately recreating subjects such as tire or shoe tread patterns, and small threaded items like pipe and bolts can be difficult.
• Photogrammetry works ideally to capture fine detail and texture overlay the model with paint color, rust patterns, dirt, or whatever physical markers may be on the evidence.
• Final 3D models make outstanding visual presentations to clients or juries.
• Models are interactive and can be annotated with pertinent data and information.
CASE STUDY3D Photogrammetry Evidence Visualization
Rusted and Broken Threads
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Sketchfab
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Old Clay Pipe
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Foundation Rubble
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Tire Treads
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