Virtual Spectator

Using 3-D graphics to broadcast additional match information

If you remember, some time back when India was being thrashed by the Kiwis in New Zealand, some new type of graphics were being shown on TV. Instead of tardy 2-D wagon wheels for the shots played, it showed color-coded 3-D views of a wagon wheel. This actually showed the path taken by the ball before it crossed the boundary, and the placement of fielders on the ground depicting a ‘theoretical’ area of influence. These views were fairly realistic representations, generated by a 3-D rendering machine called Virtual Spectator. 

Before a match starts, an aerial photograph of the ground and the surrounding area is taken. Pictures are also taken by somebody standing on the pitch. These photographs are then used to make a 3-D model of the stadium in 3D studio MAX.

People wearing team colors are also photographed. This is mapped to 3-D player models created on the screen. 

The Virtual Spectator system consists of two machines. One is used to record live data from the match, like score, fielders’ positions, where the ball was hit and how high it bounced. The data-entry operator sits in a high position to get the whole view of the ground. The other machine is used to provide feed to the broadcaster, and its operator works out the various graphics based on data coming from the first machine. These graphics may include field placements on the screen, proposed field placements , wagon wheels, etc. The graphics are fed to the broadcaster through a BNC cable using a digital down converter that takes the DVI monitor feed from the computer and grabs a particular area of the screen and converts it to industry standard SDI. The BNC cable comes to the video mixer directly and the director uses the feed as needed.

The software used is written in C++ with MFC (Microsoft Foundation Classes) for the interface and OpenGL for graphics.

Both machines used are 2.4 GHz P4 processors with GeForce 4 graphic cards for great graphic results. Animation Research Ltd, a New Zealand company, has developed the product.

Geetaj Channana