Model Builder is an excellent tool for getting a head start on your Autodesk InfraWorks project by autogenerating a 3D model representing existing site conditions. After you designate your site’s location and target coordinate system, the utility will pull alignments for roads and rail from OpenStreetMap, buildings and waterways from OpenStreetMap, aerial imagery from Bing Maps, and surface data from USGS (for sites in the United States). The only problem is that the resulting model may not appear as one would expect. Compare the InfraWorks model in the top image to the Google Earth model in the bottom image:
Here are some suggestions on how to proceed:
1. You do not need the roads unless you are tying into them. I suggest you turn them off using the Surface Layers dialog. If you are tying into them, create a short piece of roadway over the existing road over the image at the tie-in location; use this to create the “tie-in” intersection and it will appear you are rehabbing that area. Be sure to create a road style that matches the road geometry.
2. If the imagery is not crisp enough, use ArcGIS to extract high-resolution imagery of the area. Or you may download imagery from other locations but you must receive a world file with that image in order to place it onto the site with ease. You can turn the Model Builder imagery off in the Surface Layers dialog. Be sure to drape the new imagery over the ground surface.
3. You can replace buildings within the proximity of the site with 3D models created in AutoCAD, Sketchup, or even Revit. You can also download buildings that are similar in style from Sketchup’s 3D Warehouse; if the building model is similar in style, no one may notice if the dimensions are slightly off; and you can always map new materials to them after you place them in InfraWorks.
4. Of course, Model Builder does not place trees or other types of landscape. Using the tools in InfraWorks, you can quickly add landscape which will exponentially improve the look of your model’s existing conditions. You may use Style Rules to automatically randomize tree types while you are “planting”.
Creating a model that portrays existing conditions resembling actual conditions is a valuable step in the 3D rendering process. If the audience cannot picture how your design will impact the site, it maybe difficult winning their approval. Consider Model Builder content a “template” (so to speak) for you to use to start your site model. Remember, it’s okay to tweak Model Builder data.
– Cyndy Davenport