Building 3D models
We use 3D modeling and visualization very frequently and also in Geographical Information Systems, especially for modeling 3D city models. But creating 3D city models is not only simply modeling of sites, buildings, infrastructure and landscape elements, but it also thinking how to present them in the easiest way, where Level of Details (LoD) is the important concept in 3D city modeling.
I and my groupmate Gulzhan Kerimbay tried to learn about LoD and used it in our project of “Geocommunication” lesson, with the help of our tutor – Martin Loidl .
So what is Level of Details? LoD is a simplification of a complex object, when we create different kinds of LoDs to reduce the rendering cost of small, distant, or unimportant geometry, for instance the number of polygons in character model (LoD paradigm):
Fig.1:Simplification of a complex object
The current LoD concept was developed primarily for the “Building” module. It distinguishes between block models (LoD1), a representation roof forms and a shape of the building’s facade (LoD2), a representation of the exterior shell (LoD3) and a representation of internal structures (LoD4). All 5 Levels of Detail in the Building module are depicted in figure 2:
Fig.2: 5 Levels of Detail in the Building
“Level of Details” was implemented in our hands-on work. 4 Level of Details were shown in 3D model of Techno Z building (Salzburg, Austria). And the SketchUp 3D modeling program was used for 3D representation of Techno Z building . So below the result of work:
Fig.3: LoD0 – 2, 5 D with digital terrain model
Fig.4: LoD1 – Building block model without roof structure
Fig.5: LoD2 – Building block model with roof structure
Fig.6: LoD3– Building block model including architecture
Fig.7: Techno Z – 3D building model
Fig.8: Techno Z – 3D building model