Virtual reality via photogrammetry
John D. Zahrt, George J. Papcun, Russell K. Childers, Naama Rubin · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1996
We wish to walk into a photograph just as Alice walked into the looking glass. From a mathematical perspective, this problem is exceedingly ill-posed (e.g. Is that a large, distant object or a small, nearby object?). A human expert can supply a large amount of a priori information that can function as mathematical constraints. The constrained problem can then be attacked with photogrammetry to obtain a great deal of quantitative information which is otherwise only qualitatively apparent. The user determines whether the object to be analyzed contains two or three vanishing points, then selects an appropriate number of points from the photon to enable the code to compute the locations of the vanishing points. Using this information and the standard photogrammetric geometric algorithms, the location of the camera, relative to the structure, is determined. The user must also enter information regarding an absolute sense of scale. As the vectors from the camera to the various points chosen from the photograph are determined, the vector components (coordinates) are handed to a virtual reality software package. Once the objects are entered, the appropriate surfaces of the 3D object are `wallpapered' with the surface from the photograph. The user is then able to move through the virtual scene. A video will demonstrate our work.