|An Immaterial Depth-Fused 3D Display|
We present an immaterial display that uses a generalized form of depth-fused 3D (DFD) rendering to create unencumbered 3D visuals. To accomplish this result, we demonstrate a DFD display simulator that extends the established depth-fused 3D principle by using screens in arbitrary configurations and from arbitrary viewpoints. The performance of the generalized DFD effect is established with a user study using the simulator. Based on these results, we developed a prototype display using two immaterial screens to create an unencumbered 3D visual that users can penetrate, enabling the potential for direct walk-through and reach-through manipulation of the 3D scene.
Simulation of a General DFD Display
We demonstrate the feasibility of the DFD principle with arbitrary screen configurations and arbitrary user position using a stereoscopic 3D graphics simulator we implemented. Virtual transparent screens are observable to the user in different configurations. Each of these screens show a specifically calculated contribution of the whole 3D scene in between the screens using per-pixel accurate intensity values. When the individual screens overlap with the other screens, a 3D image impression is created in the visual system of the observer. Note that this still allows the user to freely move in and interact directly with the virtual scene, but several requirements and limitations of the DFD technique need to be mentioned: First, we need to track the user's head pose, since the 2D images displayed on each screen are dependent for the user's specific viewing direction and are computed in real time, and second, a 3D impression occurs only when the user looks in a direction where two or more screens overlap each other and depict objects in between them.
Evaluation of the Simulator
To evaluate the effectiveness of a general DFD display, we conducted a study comparing the 3D perception of different display configurations within our simulator.
Prototype of a Walk-through DFD Display
The system we assembled uses two FogScreens, each with their own standard DLP projector, in the stacked and L-shaped configurations. For head-tracking, we use WorldViz's Precision Position Tracker, which tracks the 3DOF position of an infrared LED inside our viewing volume, using four infrared cameras placed around the display system. The displays are driven by a single desktop computer with a Quadro FX 4500 graphics card. The images on the screens are generated using the same DFD technique implementation as in the simulator, to ensure visuals are consistent across the two systems.
C. Lee, S. DiVerdi, and T. Höllerer