3D-skanning som teknik för digital hopsättning - Ett alternativ till fysisk hopsättning inom aktiv konservering

Abstract

This thesis aims to test and assess 3D-scanning and digital reassembly of objects in conservation. To do this, two 3D-scanning techniques have been tested, first scanning with structured light and secondly photogrammetric triangulation. The reassembling was done in Meshlab for the structured light and in Agisoft Metashape for the photogrammetric triangulation. The research questions were: How does these scanning techniques work for digital reassembly of objects in conservation and how does the result differ between the two techniques? How can the working process look when using the techniques for digital reassembly and what is important to consider to achieve the best possible result? The objects used in this examination was a terracotta pot, the breastbone from a bird and a skull from a deer. The three objects were scanned, two were later broken and the fragments were scanned again and then digitally reassembled. All three objects were scanned with structured light and the breastbone was also scanned with photogrammetric triangulation. The result shows that there are many aspects to consider in the working procedure. After evaluating the result, it was clear that one important factor to get good 3D-models and good texture on the models was to have good light conditions. This is especially important when using photogrammetric triangulation. Both scanning techniques were relatively fast and easy to use but because the camera was fixed in structured light it was harder to control the process compared to photogrammetric triangulation. Using photogrammetric triangulation also gives the possibility to take photos from different angles but requires more settings to get good and high-quality images. Meshlab and Agisoft Metashape both requires good computer capacity for usage. The conclusions were that 3D scanning and digital reassembly is possible to apply in conservation and can be an alternative to physical reassembly. Furthermore, conservation knowledge and skills in non-destructive supporting materials and stabilising arrangements could improve the work process. It is also important to have a critical perspective in the digital process, as there are many choices that impact the reliability of the digital output.