To produce the 3D PDF below, I performed the photogrammetric pre-processing in LPS and then extracted 3D building vectors in PRO600 Fundamentals (which runs on top of Bentley PowerMap) via stereo feature extraction. After that, the steps are:
1) From PowerMap set the View extent to the area to be exported.
2) Choose File > Print. This opens the dialog below.
3) Ensure "Plot to 3D" is checked.
4) Choose Settings > 3D Plotting: you may want to change some settings such as the background color and a number of advanced settings.
5) Choose File > Print (from within the Print menu) when you're ready to save out the 3D PDF.
Click on the image below to download the 3D PDF I generated. I didn't get into any sophisticated modeling, but the tools within PowerMap and MicroStation will allow for creation of highly realistic models.
This post also gives me a chance to try out Scribd: check out the 2D PDF I exported from PowerMap as well, with imagery as a backdrop. Personally I like the zoom and pan functionality as well as full-screen mode: a nice alternative to viewing in Acrobat...
Los Angeles Ortho and Vectors See here for some more 3D PDF examples from the Bentley MicroStation V8i page.