How We Did It
The Amarna Virtual Museum brings together a number of innovative approaches to the capture and distribution of digital information. This section provides an overview of how the data was acquired and the steps taken for making the data presentable.
The process of digitization begins as laser scans of the original objects collected with a Konica-Minolta VIVID 9i system. As the laser scans across the surface of an object, it collects a series of x, y, and z point data (called a point cloud) and sends it back to the computer, where the points can be visualized in 3D digital space. The VIVID 9i also has a digital camera that records a color image during the scanning process. As a result each location in three dimensional space has x, y and z as well RGB (or red, green and blue = full color) values associated with them.
The laser scanner only scans what it can see, and typically the scanner can only see a part of an artifact at a time. In order to collect the data from an entire artifact, we must make several scans from different sides of the artiact. To facilitate the process the VIVID 9i comes with a turn-table that rotates the item a precise 60 degrees between each scan. Usually additional scans are needed to collect data for the tops and bottoms of objects.
The next step in the process is to merge these scans into a single digital object. For this purpose software from InnovMetric called PolyWorks is used. The software reads the multiple scans and, with some input from the analyst, automatically merges them into a single point cloud covering all the surfaces. A variety of editing steps are necessary to remove the extraneous data and clean up the point cloud. More details on the technical process will shortly be provided here.
The laser in the laser scanner only provides the three dimensions. The digital camera in the system (or sometimes a separate camera) records the color texture or image of the object. Taken alone, the laser scanner provides a grey scale representation of the object. When the color data is integrated with the dimensional data a more photo-realistic digital object is created.
To obtain an accurate representation of the color of an object, it is critical that the object be uniformly illuminated so that there is no shadow or change in color intensity as the object rotates. In order to provide for this uniform illumination a light tent was developed for scanning the artifacts. In instances where there were continued color inconsistencies within an object, the data were brought into Inus Technology's Rapidform software where the RGB data were adjusted.
The final step in the process involves converting the edited point cloud to various mesh file formats that can be used in other 3D software applications. In the Amarna Virtual Museum, the models are available for download in three mesh formats: VRML, 3D PDF and OBJ and at two data resolutions: low and high. This allows for maximum useability across different platforms. Information on the file formats and their associated free viewers can be found in the About the Models section.