Play it Again SAM Scanning Process


One of the team members, Mona Hess, describes in detail below the process of scanning SAM that took place recently at the home of Richard Ihnatowicz in London:

 

3D scanning based on fringe-projection – Chris Cornish

To produce a non-contact, metric record of the sculpture, a three-dimensional optical surface scan was provided by Chris Cornish , from Sample& Hold. After a preliminary session with a low-cost infrared sensor, called Gotcha, the compatibility of the surface for 3D scanning was established.

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Chris calibrating the scanner

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Scanning SAM

A more accurate 3D scanner based on triangulation by a fringe projector and and a calibrated camera, produced a complete set of surface measurement results, with a submillimeter resolution . After SAM had been placed on a turntable to enable easier ‘in the round’ scan, the total time for 3D scanning took only about 4 hours.  The different view points, were also taken from above and below, could now be mathematically aligned in the software. The 3D scan produced a surface model from all sides. Even though the surface was potentially challenging, the aluminium vertebrae being shiny and of complex geometry, and the fibreglass ‘head’ being half transparent, the Mephisto 3D scanner produced excellent results that can now be used for the 3D reconstruction and remodelling into a surface model in CAD (Computer Aided Design).

 

3D Microscribe documentation – Alex

A contact-based engineering tool, a Microscribe-3DX, was included in the documentation progress to produce a record with a selected set of surface points by tracing along its contours. The microscribe consists of a mechanic counter-balanced arm with six degrees of freedom and features a touch probe.  The methodology is closer to the manual engineering drawing. The outcome are a series of points, directly readable by CAD software, and will be used to complement the 3D surface measurements, to re-engineer the sculpture.

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Alex using the Microscribe touch probe

 

 

2D documentation: film and photography – Mona and Emily

Next to a time-lapse video, taken with the iPad throughout the day, a comprehensive photographic documentation of all steps was taken. These included , setting up, calibration of the 3D scanner, use of the microscribe methodology, and subsequent steps to record all surfaces.

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Film – Interview with team members and Richard Ihnatowicz – Emily and Mona

Every team member is contributing a different technical and curatorial aspect to the project, therefore we were very interested to document the motivation and decisions of every team member.  Jana’s point of view will soon be added. We were grateful to include Richards impressions and memories about the ‘genesis’ of the sculpture. The video’s will also serve to introduce the team for the final symposium.

 

SUMMARY

Next steps will include archival work and modelling of the acquisitioned 3D data. An metadata-set of the technical hard-and software of the 3D technologies will be recorded, to serve as metadata alongside the decision making processes for further modelling and subsequent steps towards a physical and virtual replica.

This project is exemplary in the use of technology, originating from engineering quality control (2) and entertainment industries (1), and their use for the digital documentation of an artists sculpture. These digital documentation technologies are complementing the more conventional methods, like photography, film and consultation of drawings, used to grasp the gist of the ‘biography of the object’ and its physical appearance.

But the dialogue with people involved in the making of the sculpture, with their memories, are a priceless addition to any archival documentation process.

We thank our kind hosts, Richard and Carol, for welcoming us into their home for the day and making this project possible.