Creating Internet Friendly 3D Tours Using 3D Range Scanner Data
The case of a Byzantine Castle in Northern Greece

The castle (Acropolis) of Kavala is located on the top of the Panagia (Virgin Mary) peninsula where the old town is built. During the Byzantine times successive reconstructions and operations for the fortification of the town took place. The castle, as we see it today, was built in the first quarter of the 15th century, based on the Byzantine era's foundation. It is a two bailey castle with a tower situated in between.

The equipment used for the digitisation of the castle included, apart from a typical 6MP dSLR camera, a time-of-flight 3D colour range scanner (Optech ILRIS-3D).The raw scan data composed of 36 millions 3D points. These partial scans were merged using the Iterative Closest Point algorithm and with further processing (overlapping elimination, noisy and unnecessary parts removal) resulted a 27 millions 3D points.The final model is composed by 15,000 polygons and it can be described using the VRML 2.0 format with a total of 430KB (gzip compressed).The size of the texture images was 15 MB compressed using the JPEG algorithm. The texture baking technique has been used to display in real time ambient occlusion shadowing.

In order to experience the virtual tour with the ambient occlusion shadows it is required to have installed the BS Contant VRML 7.1 viewer which supports double texturing. You can download the BS Contact viewer from this site. Otherwise, you can experience the vertex paint version which is compatible with all VRML viewers including the Cortona VRML Client.

Optimum Settings for the BS Contact Viewer: Game Like Control Method (CTRL+SHIFT+Q) with speed set to Fast, Collision Enabled (Ctrl+Shift+C), Gravity (Ctrl+Shift+G), MIP MAPPING ENABLED using OPENGL as the Rendering Engine.

Ambient Occlusion Shadows Version
Vertex Paint Shadows Version
Click on the image above to start the virtual tour
Click on the image above to start the virtual tour
Copyright 2008 - Cultural and Educational Technology Institute / Research Centre 'Athena'