Closely associated art forms are projectors, 3-D map projection, multi-media, video art, and photography where light technology projects images rather than using light as the medium. Large light festivals and events have helped to develop the use of light on large canvases such as architectural facades, building projections, the flood lighting of buildings with colour, and interactive media facades. These forms of light art have their antecedents in new media-based, video art and photography which are sometimes classified as light art since light and movement are important to the work.