To follow up the discussion of my quick and dirty Revit model OBJ exporter, I want to point out that Adam Nagy completed his series of posts on the AEC DevBlog on a Revit model exporter and viewer for iOS using an even more minimalistic custom data format for uploading to the cloud and viewing on an iOS mobile device:
- Part 1: Revit add-in to upload geometry data to a storage service
- Part 2: An iOS application to download and display the model using OpenGL
- Part 3: Interactive view orientation and manipulation using gestures
While the OBJ format I looked at is more heavy-weight than Adam’s minimal custom format, my implementation includes some other enhancements which make it quite effective as well.
I have also heard of other home-grown viewer implementations with some support for switchback, individual element tagging and object identification based on VRML and on the Unity gaming engine.
If you are interested in a finely tuned exporter with more complete coverage and control over what gets exported, you might want to take a look at the open source STL exporter.
Finally, for high-end exporter requirements, the Revit IFC exporter is also open source.