Projection mapping

Projection mapping is the use of projectors to manipulate a piece of internal or external architecture. This is achieved by covering the surface with light from the projector. If it is a particularly large, or three dimensional layouts, more than one projector can be used, and then linked through a single computer. Once the surface is satisfactorily covered, there is usually what is effectively an overspill, where light may be falling on the pavement in front of the selected surface, or onto the ceiling. These areas are then removed by applying a layer of black pixels on the screen in the correct place, so light there is no longer bright enough to register. The light in place works in the same way as a light bulb, so the surface appears lit by a spotlight if entirely black. With the work area in place, the surface needs to be laid out by using UV mapping, similar to 3D program such as Maya. This works by applying and moving a grid on the projection to be evenly placed, moving the lines to be an equal distance apart. Any separate walls can be laid out and added to a master copy. With the surface in place, animations can be placed onto the grid to correspond with the architecture of the building, for instance a window can be outlined with a V glow, or certain parts of the façade can be coloured. The surface becomes a breathing canvas, which can be edited however the artist wishes. Advertising companies are frequent users of the technique, manipulating flagship shops or newly opening buildings, however some have branched out, recently cars have become a popular surface. Acting as a lightshow, passersby and people who are aware of the event can revel in the attraction of seeing concrete architecture move, spin, fall apart, change colour and pulsate. Specialist software is available on commercial licences, and is popular amongst VJs in live arenas as well as architectural mappers. The technique of laying out UVs will be needed in some form should I press ahead with an environment.