Virtual Reality Raises Dresden Church From Rubble : Restoration: Using a headset, viewers can ‘see’ building’s ornate interior. Computer scientists’ model will be used to generate money to rebuild the historic structure destroyed in World War II.

As workers in Dresden, Germany, lay the first stones to rebuild a Baroque church destroyed in World War II, computer scientists here are creating a 3-D version of what the finished project will look like.

Using a virtual reality headset, viewers can see the blue doors of the church open to a view of the ornate ivory and gold altar and the organ that Johann Sebastian Bach played in 1736.

Light coming through the Protestant church’s clear windows illuminates paintings of the Apostles in the inner dome, which virtual tourists can observe more closely by pushing a button to “fly” up there.

IBM Germany hired the scientists at Research Triangle Institute to help create the virtual reality model in order to generate money to rebuild the actual Frauenkirche, or Church of Our Lady, said Robert Haak, special projects manager for IBM Germany. The reconstruction is expected to cost about $150 million.

Some critics have questioned the wisdom of spending such a large amount of money on the ruined church, which lies in the economically strapped former East Germany.

But Haak says most Dresden residents support the project. All but 10% of the money comes from private donations.

“One could think it’s more important to build apartments,” Haak said in a telephone interview from his office in Stuttgart. “But the people of Dresden want this.”

The Foundation to Rebuild the Frauenkirche, a private group made up mainly of Dresden residents, has been working since the late 1980s to generate support for the reconstruction.

IBM Germany offered its help in 1989, providing money, equipment and consultants, and workers last year began clearing rubble from the site. They expect to complete the project by 2006, the 800th anniversary of the city of Dresden, Haak said.

The original church, on the Elbe River, took about 16 years to build and was completed in 1742.

The church survived the Allied bombing that destroyed much of Dresden in February, 1945, but toppled in the firestorm that immediately followed.

“It was a very elegant city,” said Gerhard Weinberg, a professor specializing in World War II history at the University of North Carolina at Chapel Hill.

Weinberg said rebuilding the Dresden church has political and social significance for eastern Germany.

“It’s the general sense of rebuilding religious life in a society in which religious life was tolerated but discouraged by the Communist regime for decades,” he said.

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The virtual reality model of the church received rave reviews in March, when it was unveiled at a computer trade show in Hanover. One person donned a special helmet and maneuvered a hand-held control to navigate the tour. For the demonstrations, the images were projected onto a small theater screen to be viewed by people wearing 3-D glasses.

The scientists plan to set up a similar demonstration pavilion in Dresden in September, Haak said.

The church’s interior is one of the most complex virtual worlds ever constructed, said Dale Rowe, director of RTI’s Center for Digital Systems.

Three RTI computer scientists--Jorge Montoya, Steve Duncan and Jim Chung--developed the virtual reality model of the church’s interior from an animated model, similar to a computer-generated film, supplied by IBM.

A French computer graphics artist, Luc Genevriez, directed a team of artists who drew the church’s interior, working from architectural plans, historical descriptions and prewar black and white photographs.

Haak said only one color photograph existed. In 1943, Adolf Hitler ordered that color photographs be taken, and one was recently found in Munich. The photo shows the church’s inner dome, and Genevriez used it when depicting the painted Apostles.

IBM scientists in New York and the United Kingdom did the calculations for the animated computer model.

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The RTI scientists’ task was to convert the animated model to a version that an individual could “walk through” in real time, Rowe said.

The animated model took 2 1/2 hours to generate a single scene. To walk through the models in virtual reality, the researchers needed to generate 30 frames per second.

The complexity of the animated drawings complicated the project, Rowe said. The scientists developed a way to simplify the images by mimicking the focus of the human eye and narrowing the field of view.

RTI also enlisted the help of a powerful graphics computer owned by Silicon Graphics of Mountain View, Calif., which helped generate the dinosaurs in the film “Jurassic Park.”

Haak said the RTI scientists are still working to increase the speed of the virtual reality church before the September demonstration in Dresden.