The continuing story of our recent art installation project. Today - it's time to delve into the technical side of the project...

With the physical installation and design/animation direction agreed, the next stage was to research and implement a delivery system that would fulfil the following requirements:

- To display the animations on a 4m x 1m surface in as high a resolution as possible. The most likely configuration would be three 1024 by 768 'screens', displayed edge to edge. (Luckily this gives a resolution of 3072 x 768, which is exactly 4:1)

- To be able to display multiple content types, such as QuickTime movies, images, openGL containers and Quartz Compositions

- To generate the animations in such a way that the key assets and text within them were created at run time, and hence would be easy to edit

- To run from one computer, to simplify installation and maintenance

- To provide edge blending and other alignment tools to reduce the need for physical projector alignment

The very high graphical requirements ruled out any off-the-shelf software. Instead, we decided to build our own display engine, written in Cocoa, which could then utilise both OpenGL and Apple's Quartz Composer

Although the Eye display would be comprised of three 'screens', we decided to show the animations using four projectors, with a great deal of overlap between them. The alternative was to butt the three screens together with no gap between them - something which would be very difficult (if not impossible).

Using overlaps created a new problem: the areas of overlap were much brighter than the rest of the display.

The engine displaying a simple alignment grid.

To counter this, the Engine needed built in edge-blending:

Test pattern with no edge blending - note the blue area on the right hand side.

Test pattern with edge blending.

In addition to edge blending, we also added a variety of other tools to the Engine, including: x and y position editor, colour balance editor and the ability to rotate each 'screen' on its x, y or z axis.

Our early tests with the Engine used trailers for Ratatouille and - heaven forbid - Fantastic Four, so it was a delight when we were finally able to show prototype animations at full size:

A demo animation projected onto the wall. Note that the screens are not perfectly aligned; some blurring is visible on the latin body text.

After experimenting with different media types, we discovered the optimum set was as follows:

- QuickTime, for full screen animation elements

- Quartz Composer, for individual animated objects built around live images and movies

- OpenGL, for animated on-screen text

Animation elements were controlled and synchronised via a markup language developed especially for the Eye. We used an existing Cogapp technology, CEF, to author and edit the xml files, and then developed a schedule function so it could show any story or combination of stories at any time.

The innovation theme explodes into life, a combination of QuickTime, Quartz Composer and OpenGL.

In the next blog: finalising the animations, late night installation, robots and remote desktop...