A 3D projection is a design technique used to display a three-dimensional (3D) object on a two-dimensional (2D) surface. These projections rely on visual perspective and aspect analysis to project a complex object for viewing capability on a simpler plane.
Axonometric projection of a scheme displaying the relevant elements of a vertical picture plane perspective. The standing point (P.S.) is located on the ground plane π, and the point of view (P.V.) is right above it. P.P. is its projection on the picture plane α. L.O. and L.T. are the horizon and the ground lines (linea d'orizzonte and linea di terra). The bold lines s and q lie on π, and intercept α at Ts and Tq respectively. The parallel lines through P.V. (in red) intercept L.O. in the vanishing points
Projection mapping, similar to video mapping and spatial augmented reality, is a projection technique used to turn objects, often irregularly shaped, into display surfaces for video projection. The objects may be complex industrial landscapes, such as buildings, small indoor objects, or theatrical stages. 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 then interact with a projector to fit any desired image onto the surface of that object. The technique is used by artists and advertisers 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 audiovisual narrative. In recent years the technique has also been widely used in the context of cultural heritage, as it has proved to be an excellent edutainment tool.
The Sydney Opera House during the 2013 Vivid Sydney projection display