SMR No.: ME019-030001-
Monument Type: Megalithic Art
Basin stone located in the northern recess of the eastern passage at the megalithic passage tomb at Knowth. Probably installed before construction of the recess was completed, as it is too large to be positioned once the structure was completed. The basin stone is approximately 1.2m in diameter and sculpted from a single block of sandstone with a portion of the rim missing to the rear and some damage to the right rim. The basin originally contained the cremated remains of several humans.
Interior decoration: Circular design containing radial lines, circles and crescent shape.
Exterior decoration: Parallel design of lines lines running around the side of the bowl. Design at front exterior of bowl within lines of concentric circles consisting of a crescent shape with smaller circle position to the top right. Right side of bowl displaying design of four vertical parallel lines.
3D Capture Method: Close range Scanning
3D Capture Description: The Artec EVA scanner is used to generate high resolution models of surfaces with small scale detail. The Artec EVA uses structured light to record. A forensics tent is used to create a controlled lighting environment and ensure measurement can proceed regardless of the weather when used outdoors. Scanning is undertaken with the fastest speed setting (15 frames per second) and with a minimum 400 mm depth of field. The data is recorded with sufficient overlap between scans to ensure easy registration.
- Resolution 0.5 mm
- Accuracy 0.1 mm
- Accuracy over distance 0.03% over 100 cm
- Texture Resolution 1.3 mp
- Colours 24 bpp
- Light Source flash bulb (no laser)
- Video frame rate 16 fps Exposure time 0.0002 s
Post-processing is done in Artec Studio 9 software: individual scans are edited, aligned, before a final surface is generated using global registration, fusion, and a small objects filter algorithm. If required, a textured surface can also be created. The model is exported from Artec Studio 9 as an .obj file. For dissemination purposes a 3D pdf of the model is generated using Geomagic Studio 2012.
Data Processing Software: Artec Studio 9 & Geomagic Studio