# A Methodical Approach to 3D Scanning of Heritage Objects Being under Continuous Display
## 5 Results and Discussion
### Case Study 3--\"Buddha\"  
The surface of the statue with a uniform, non-glossy texture (limestone) made it possible to perform 3D scanning from the minimum allowable distance. It was important due to the limited space inside the display case.  
Three dimensional scanning of the statue lasted 45 min in total. It took 35 min to scan the statue's front. 15 scans were made with different orientation and trajectory of the scanner in relation to the object. The aim was to obtain the fullest possible scan of the deep grooves (especially in the area depicting leaves of a Bodhi tree). In addition, five scans of the statue's rear surface were made, using the scanner placed outside the display case. Scanning that part took 10 min. Despite many attempts to scan with different  
Figure 8: 3D dissemination model of the “Snake” figure [40].  
The side walls of the grooves in the area of a Bodhi tree leaves and the grooves around the monks have not been completely digitized. The problem here was not so much limited access to the object due to the display case, but the shape of the grooves: narrow, deep gaps smaller than the dimensions of the scanner. It was not possible to position the scanner so that it could properly see the problematic surfaces of the grooves with all its cameras. The statue's rear part, despite scanning through the glass, did not show similar problems (mainly due to a fairly uniform surface without major depressions and gaps). The scan matching process did not reveal any significant deformations due to potential interference while scanning through the glass.  
During the data processing stage, the obtained partial scans underwent processing and assessment, which lasted 5.3 h. As a result, two scans of unsatisfactory quality were rejected. The remaining 18 scans were used to generate the high-quality base 3D model (Figure 12--on the left). It was estimated that the obtained model covered 85% of the original \"[PERSON]\" statue. Luckily, the obtained fragmentary scans of Bodhi tree leaves turned out to be sufficient to apply the algorithms for filling gaps in the meshes of triangles, obtaining the effect visually similar to the original (Figure 12--on the right). A similar situation took place in the areas around the monks, although this time the deviation from the original is more evident. Nevertheless, it was possible to obtain a complete 3D model of the statue, reproducing the original sufficiently in terms of shape and color--which was the main purpose of the scan (Figure 12--on the left).  
It took another 1.2 h to prepare the dissemination 3D model (Figure 13) for the purpose of publishing it on the 3D Digital Silk Road Portal [39]--similarly as in the case of the \"Snake\" figure. Again, the time spent is mainly the result of finding a balance between the model quality and mesh complexity, thus providing fair performance for the viewers. Although this time the mesh was noticeably more complex.  
It was the most complicated of the cases used. It can be seen from the long preparing, scanning and restoring times that lasted 70 min in total. Due to the dimensions, hard accessibility and troublesome shape of the surface influencing the scanning approach, the size of scans was large, just as the processing time leading to the 3D base model. To conclude, in this case, the methodology applied was verified successfully, despite the final model not fully complying with the original heritage object.  
Figure 11: Incomplete 3D scan of the “[PERSON]” statue.