Constructing Digital Archive in a 3D space.
Citadel of Bam, Iran
Our challenge is on the 3D virtual reconstruction of Citadel of Bam, Iran, which is totally destroyed by the earthquake, with the goal of using the virtual reconstruction to the physical reconstruction in the future. Important parts of the citadel are now being reconstructed by experts, but we are planning to combine automated reconstruction using computer vision techniques toward the reconstruction of the whole citadel.
Most important parts of the citadel have been reconstructed by experts. Unfortunately we do not have precise measurements of the buildings before the earthquake, and the reconstruction requires the integration of heterogeneous data based on expert's knowledge on the building. This process cannot be done by automated methods, so two groups of people - architects for managing CAD data, and CG designers for rendering 3DCG - worked together for reconstruction, The summary of the achievements is available on the following page.
Various data used for reconstruction, more detailed explanation for experts, and more photographs and videos are available in the following Web site.
3D Reconstruction using Computer Vision
Manual reconstruction is better in accuracy because it is based on the knowledge of experts, but the whole process is very costly so it is not realistic to apply manual methods for the whole citadel. For less important parts of the citadel, we need to apply automated methods for reconstruction. Toward this goal, we are now doing research on the following topics.
- 3D reconstruction from multiple photographs
We first collect tourist and recording photographs from around the world, and construct 3D models from them. Due to the lack of camera parameters, less linear features, and small number of photographs, we concluded that this method is technically very difficult at this moment.
- 3D reconstruction of video taken from a helicopter
We are exploring a method for reconstructing 3D models from video taken from a helicopter.
- Overlay of photographs on digital elevation models
We are exploring a method for making pseudo 3D models by overlaying photographs on digital elevation models.
Bezeklik Caves, China
Bezeklik Caves in China is famous for very good wall paintings preserved under the sand, but those wall paintings were completely removed by German expedition Team and brought back to Germany, and now people cannot see the wall paintings at the site (reference). They however published the wall paintings in the catalog Chotsho, we moved the wall paintings of Cave No. 9 from books to a 3D space so that people can see and imagine the wall paintings in their original forms.
Collaboration with Helmut Prendinger Lab., we made a simple 3D model of Bezeklik Caves in Virtual World (Metaverse) so that people can freely visit there and see around. To visit Bezeklik Caves in Second Life, please visit the following link.
The following is a demo video on the caves (Youtube - DSRProject's Channel).
3D models built using Google Sketchup can be visualized on Google Earth. You can see the caves in a 3D space including the (current) environment around the caves.