1. Modeling methods.
There are three ways to create 3D models [6]: Property stretching, establishing
with 3D symbols, and importing MultiPatch type data. The method of property
stretching is rarely used in ArcGIS. Besides, though such method as establishing
with 3D symbols and importing MultiPatch type data all can create 3D models, but
the shape of the 3D models generated by the same universal symbol are identical.
So the second method could not simulate the real situation. While 3D models
generated by the type of the MultiPatch collections are different, possessing their
own attribute information and being independent of each other. Therefore, in most
cases, we use the method of importing MultiPatch type data to create 3D models.
This paper mainly explores the method of importing MultiPatch type data to create
3D model as well.
2. Modeling process [7].
Firstly, the vector data is loaded into ArcMap. When the coordinate system is
set and all elements are endowed with height value, the elements to be modeled
will be selected, and then imported into SketchUp via SketchUp ESRI plugin.
Secondly, elements are modeled and rendered. In this step, we should pay attention
to the amount of the data, because the larger the amount the slower the operational
speed. When models are created completely, we export them out as MultiPatch
(*. mdb) type data. Thirdly, models are imported and reprocessed in the ArcScene.
Finally, browse the realistic 3D scene in ArcExplorer or Google Earth.