23/05/2018

Visgraf uses probabilistic editing in 'The Tempest'

Luiz Velho explica para a plateia o processo de escolha do modo de exibição

In the audience, computer engineer Bruno Madeira awaits the start of the presentation of "The Tempest," a production conceived by the Vision and Computer Graphics Laboratory (Visgraf) at IMPA, based on a work by William Shakespeare. He is seated in the same IMPA auditorium where, in January , he saw the experiment. But what he is about to witness, on the evening of Tuesday , May 22nd, is not exactly the same spectacle.

As explained by Visgraf coordinator Luiz Velho, each of the four performances of "The Tempest" held since last December is unique. The "real-time" attribute of the production influences the final result. Furthermore, the inherent interactivity of the production causes it to transform, although the changes are subtle.

In tonight's presentation, the audience is greeted with an invitation: to access an app to choose the viewing mode. The most cinematic style (68%), which prioritizes close-up shots, wins. The others opted for the more theatrical style, in which medium shots predominate.

Faced with this decision, Manoel Prazeres, the director of the show, which combines theater, cinema, virtual reality, and gaming technology, selects the cameras in real time following a probabilistic logic, automatically defined from parameters entered into the program. Although, here and there, he decides to do the framing manually.

Ayres foi um dos sorteados que assistiu a produção com equipamento de realidade virtual

While the audience enjoys the result on the big screen in one of IMPA's auditoriums, two of those present at the screening watch the spectacle many steps away, in the laboratory. Chosen by lottery, audiovisual director Márcio Ventura and IMPA doctoral student José Eduardo Ayres immerse themselves in the story of Próspera – in the Visgraf version the protagonist is female – Miranda and Ariel.

“It was fantastic to be able to decide my angle of vision. I moved my body and could see the scene unfolding from a particular perspective,” says Ayres, leaving the lab. In the discussion with the audience after the screening, Ventura suggests a change. “I missed being able to get very close to the character and thus be able to see the scene from his point of view.”

In the next showing of "The Tempest," Velho reveals, the audience can expect a closer connection between the viewer using virtual reality equipment and the characters. Other surprises are in store.

“We are already working on creating a kind of guided tour of the show,” reports the coordinator of Visgraf, who, faced with the audience's curiosity, mentions one detail or another of the tool created for the virtual reality cinematic presentation.

The topic will be discussed this Wednesday afternoon (23), in auditorium 3 of IMPA, in the seminar “Live Probabilistic Editing with Virtual Cinematography”. Velho will present concepts and applications of probabilistic editing integrated with the VR Kino+Theater platform.

Uma das cenas da produção criada pelo Visgraf e baseada em obra de Shakespeare

“One thing is the mathematical theory behind 'The Tempest'. Another is validating the process. What people see on the screen is, mathematically, a graph. We created a high-level tool to be used in editing and we are evaluating how it works. In other words, we are pedaling and changing the bicycle tire at the same time,” summarizes the IMPA researcher.

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