June 27th, 2008
Multi-projector digital dome systems are becoming commonplace, but real-time software to drive them is not. The majority of digital dome content is pre-rendered, and existing real-time software is largely proprietary and expensive. Real-time visualization is a valued goal as it enables a live planetarium show, an adaptive and interactive visitor experience, and rapid content creation. Additionally, real-time systems reduce the cost and complexity of back-end storage and distribution of pre-rendered video. Driving planetarium domes in real-time is feasible today. The video game industry has driven commodity graphics hardware capability to incredible heights at affordable prices, and this trend will certainly continue for the foreseeable future. Complex visualizations once possible only with off-line rendering can today be rendered at interactive rates. A complete system to do so costs only a few thousand dollars using off-the-shelf hardware.
But the freely available software, knowledge, and experience to support this hardware capacity has yet to catch up. In a continuing effort to exploit opportunities enabled by powerful, new hardware, the staff of the Space Visualization Laboratory at the Adler Planetarium and Astronomy Museum has installed an inexpensive cluster of off-the-shelf PCs in Adler’s full-dome theater. With this installation, we are working to implement solutions to the general problems of real-time multi-projector digital dome display, and to make them freely available, as Open Source software. We hope we can encourage and assist others in the creation of new dome software and in the adaptation of existing visualizations to dome display.
Toward this end, we discuss techniques for real-time dome rendering. We enumerate a number of solutions to its two major challenges: spherical correction and edge blending. Noting the broad range of hardware in use today, we review the evolution of technology that made each technique possible.
Kooima, R., Roberts, D., SubbaRao, M., Real-time Digital Dome Rendering Techniques and Technologies, Proceedings of IPS2008, Chicago, IL, International Planetarium Society, June 27th, 2008.