When loading the scene (Open vrml file) for the first time if the file has been created by ArchiCAD 8.1 and subsequent versions (without any modifications), this is automatically optimized, after which the Geometry Tree (tree structure of the 3D scene) is created. Even vrml scenes not generated by ArchiCAD can be loaded and edited, but in this case they will not be optimized and Pharus does not warrant correct works with such files.
When an ArchiCAD scene is loaded for the first time the background remains black (colour default in viewer, which can be modified by means of Cortona "preferences" table) and the scene is lit by five preset direction lights (default) that can be adjusted, integrated or cancelled.