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AR Bridge Builder

AR Bridge Builder Project: Laptop, webcam and whiteboard

F. Petzold, J. Pfeil, C. Riechert, R. Green, AR Bridge Builder: Real-Time Vectorisation of Freehand Sketched Structures for an AR Application, Proceedings of Image and Vision Computing New Zealand 2007, pp. 192–197, Hamilton, New Zealand, December 2007.
Award for the best oral student presentation

An augmented reality (AR) version of the game Bridge Builder where the goal is to get a train safely across a river or valley. The bridge is drawn on a whiteboard using blue and red markers. Blue for the trusses and red for the anchor points.

Our computer vision algorithm recognizes the bridge and its anchor points. The resulting model is simulated using PhysX and overlaid over the camera image on the laptop monitor. Tension and pressure on the trusses are visualized using shades of blue and red, respectively.

The simulated bridge is drawn perspectively correct using the camera position and orientation at the start as a reference coordinate system. This works because all the points of the bridge lie on a flat surface, enabling us to compute a homography.

// Hardware
webcam, whiteboard
// Software
C++, OpenCV, PhysX
// People
Frank Petzold
Jonas Pfeil
Christian Riechert
// Advisors
Prof. M. Billinghurst
Dr. R. Green
// Year