Projection Mapping

Projection mapping, also known as video mapping and spatial augmented reality, is a projection technology used to turn objects, often irregularly shaped, into a display surface for video projection. These objects may be complex industrial landscapes, such as buildings, small indoor objects or theatrical stages. By using specialized software, a two- or three-dimensional object is spatially mapped on the virtual program which mimics the real environment it is to be projected on. The software can interact with a projector to fit any desired image onto the surface of that object. This technique is used by artists and advertisers alike who can add extra dimensions, optical illusions, and notions of movement onto previously static objects. The video is commonly combined with, or triggered by, audio to create an audio-visual narrative.

Although the term projection mapping is relatively new, the technique dates back to the late 1960s, where it was referred to as video mapping, spatial augmented reality, or shader lamps. One of the first public displays of projections onto 3D objects was debuted in 1969, when Disneyland opened their Haunted Mansion ride. The ride used fake disembodied heads as objects which had 16mm film projected onto them to make them appear animated. The next record of projection mapping is from 1980, when installation artist Michael Naimark filmed people interacting with objects in a living room and then projected it in the room, creating illusions as if the people interacting with the objects were really there. The first time the concept of projection mapping was investigated academically was at the University of North Carolina at Chapel Hill in the late 1990s, where scholars worked on a project called Office of the Future to connect offices from different locations by projecting people into the office space as if they were really there. By 2001, more artists began using projection mapping in artwork, and groups such as Microsoft began experimenting with it as a means of technological advancement.

After the object which will be projected on is chosen or created, software is used to map the corners of the video to the surfaces. First, one must choose the images or video to project. Then, place each video on to its designated surface. Alternatively one may choose to map the entire scene in 3D and attempt to project and mask the image back onto its framework. The next step is defined as "masking," which means using opacity templates to actually "mask" the exact shapes and positions of the different elements of the building or space of projection. In 3D Mapping, coordinates need to be defined for where the object is placed in relation to the projector, the XYZ orientation, position, and lens specification of the projector have to result to a determined virtual scene. One such tool to help achieve this end is BLAM! add-on for blender 3D's open source 3D animation suite. Adjustments are commonly needed and made by manually tweaking either the physical or virtual scene for best results. Large projectors with 20,000 lumens or larger are used for large-scale projections such as on city skyscrapers. Otherwise, for smaller productions, a projector with a basic lower lumens will work. A 2200 lumen projector is adequate for projections under indoor light or theatrical lighting in most cases. Video mapping software such as MadMapper, Qlab, Troixatronix's Isadora, FaçadeSignage and VPT 6.0 are all downloadable for use in projects like these, though Adobe Photoshop, Adobe After Effects, Blender Blam!, and other packages can also be used by a creative artist. Also, extensible open-source software frameworks such as MPM (Multi-Projector-Mapper) are available among others. Projection mapping can be separated into four categories:

...
Wikipedia