3D Virtual Reality Placing Live Action into the Virtual World Andrew Butler, Product Manager, Vinten Radamec

Programme makers are increasingly pushing technical and creative boundaries in a drive to reduce costs and offer ever more attractive content. Today, they have a vast range of tools at their disposal to help achieve these objectives including computer generated graphical elements that vary from simple foreground stationary graphics to fully immersive 3D virtual reality (VR) environments.

VR is becoming increasingly popular in the broadcast world and has been deployed in a wide range of applications. Its use is particularly prevalent in children’s television where live action is often combined with virtual reality.

In Bamzooki Street Rules, for example, four teams of children design their own “zooks” – 3D computer-generated creatures – which compete with each other in a range of challenges. The zooks and their games are generated in real time, and the production design submerges the teams in what appears to be four floors of an industrial building.

News and current affairs programmes have also achieved high impact results by using VR elements extensively. Coverage of the recent UK General Election, for example, featured a multi camera virtual set and a 3D “swingometer”, combined with a model of the House of Commons and a data table touch screen.

There is also growing use of VR graphics in live outside broadcasts, and particularly in sports. This has evolved from placing team logos on the pitch, to showing the distance to the pin in golf or the length of a kick in rugby and adding a ‘virtual’ offside line in football, or tracking the world record pace in athletics or swimming.

In all of these cases, the ability to interact between real and virtual elements is key in stimulating the audience’s interest and adding value to the viewing experience.

The success of this approach relies on ensuring the virtual elements precisely correspond to the real objects on the set. And to achieve this, all camera movements must be captured then tracked and communicated back to the computer that is rendering the graphic. This ensures the correct viewpoint is obtained.

This approach to tracking has a vital role to play in 2D and 3D environments. For example, Vinten Radamec offers manual and robotic tracking solutions for both which deliver excellent physical and tracking performance.

This kind of precision tracking is a complex requirement. Digital lenses provide zoom and focus data, but the rest of the information must come from the camera support equipment. Significant innovation is needed to

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deliver the location and angle with the required degree of precision. In some applications, the graphics system can be used to control the cameras through studio robotics. In most cases, however, cameras are flexible, either controlled as a group by a single operator at the robotic controller, or moved on tripods or pedestals by individual operators. In each scenario, the need for precision location remains and so the encoding of the camera support is an equally key requirement.

A Perfect Solution to Pan and Tilt

The simplest case is when the camera is free to pan and tilt but is fixed in location on a heavy-duty tripod or post.

Production values cannot be sacrificed simply because virtual reality elements are involved and it is critical that camera support movement is smooth. That means ease of counter-balance, perfect balance to ensure the camera can be left at any tilt angle, and infinitely adjustable fluid drag for both pan and tilt.

The best solution is to take an established, market leading professional pan and tilt head and add precision encoding. In the case of Vinten Radamec, they offer encoded versions of several of the most popular Vinten heads. The most recent, the Vector 750i, offers an accuracy of around 1/5000th of a degree in both pan and tilt, without changing the performance, or the external physical dimensions of the head.

This high degree of accuracy is particularly important for outside broadcast productions. For example, when a very long lens is zoomed at 100:1, a mere fraction of a degree of tilt will appear to be a significant movement to the viewing audience.

Indeed, outside broadcast applications add significantly to the complexity of providing precise position information. While in the studio, cameras tend to be used around the horizontal, in outside broadcasts this may not be the case. The camera high above the football or rugby centre line will be pointing down all the time, so the head must be able to set its zero point at any angle.

Finally, the location of the camera may not be completely stable. The use of scaffold towers, for example, is common, and they often move during operation. Without inclinometers within the head to measure and compensate for this movement, the location data will be offset and the graphics out of place.

Putting Cameras on a Pedestal

There will also be occasions when cameras need to move around the studio floor, and so must be mounted on a pedestal. In such cases, the location of the pedestal’s mounting point must be included, in three-dimensional space. This information is added to the data from the lens and the head.

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