Collaborative 3D City Modeling
- Details
- Category: 3D Building Models
Throughout recorded history humans have used maps, paper drawings, and physical models to communicate ideas relating to construction and planning. Leonardo da Vinci and his peers used detailed technical drawings and 3d perspective drawings to provide realistic illustrations of urban scenes, and “technical drawing” or “drafting” is still a foundational course taught in public schools today. Since the 1980’s, with the advent of personal computers, much of technical drawing has shifted towards computer-aided drafting. We have continued to use these techniques in the present, expanding our capabilities with advanced 3D modeling and visualization techniques. Common objectives are evident over the whole arc of this history: to document our surroundings, to visualize possible futures, and to help in the process of constructing that future state. And increasingly, these technologies have been used for objectives that may be new and distinct: movies, gaming, and digital arts; these applications in turn have driven the development of the technology to even further heights.
3D city models didn’t reach the mainstream until the early 2000’s, when a company named Keyhole developed 3D globe viewing software. This technology was the foundation for Google Earth, which is now used by both experts and novices to view aerial imagery, terrain, 3D buildings, street-level photography, and other geographically-referenced content. Google Earth and similar 3d visualizations have become commonplace in a variety of activities, ranging from individual uses like planning a trip, to collective uses like urban planning.
The 3D city model is a platform which can support many uses, and there is power associated with the control of that platform. By providing such a platform at no cost, Google can help steer users towards Google’s core business function (advertisement). However, to provide the best user experience for the greatest number of users, Google must often rely on commercially-licensed aerial imagery and buildings models; the “terms of use” associated with commercial datasets often limit the potential for individuals to freely reuse the content in creative ways. So, while commercially-licensed 3d city models (and virtual globes more generally) are extremely useful for many applications, there are still situations in which an independently produced 3d city model may be preferable.
It is the goal of the 3D Blacksburg project to produce a 3D city model for Blacksburg that will be less constrained by licensing and terms of use limitations, and in the process, engage the community in the development of new applications for 3D city models. But producing a 3D city model is a lot of work; that’s why most 3D city models cost thousands of dollars. To produce a 3D city model that will be placed into the “commons” will require a collaborative effort, with experts providing guidance, and interested students and private citizens volunteering their efforts –but hopefully learning something and having fun in the process!
To help guide the creation of 3D building models for the virtual city, the Virginia Tech Center for Geospatial Information Technology (www.cgit.vt.edu) will provide reference data that can be used to help individuals determine the 3d position and size of the building models they create. This reference data will come from sources that agree to make their data publicly available for this project; initially, this reference data will include legacy datasets that have been released to the public by the Town of Blacksburg. As the project progresses, other sources of reference data may also become available (depending on license restrictions associated with each dataset).
Individuals interested in creating a 3D building model will download a “package” of this reference data in a format that they can import into their 3D modeling software. Using the reference data in combination with additional field observations, photographs, and their own judgment, individuals will create 3D building models and help complete the model of 3D Blacksburg.
