What is projection mapping?
As Wikipedia states in their definition of 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.”
With projection mapping one can create interesting visual effects even optical illusions that make the static surface seem to move. Also an important aspect of the experience is the audio that complete the illusion. Many people have seen impressive examples such as this one on a clock tower
A number of tools exist that aid with the projection mapping. Madmapper, Blendy and TouchDesigner to name a few. These tools help the aligning of the video projection to fit onto the surface.
A mapping tool is not enough however. One will need to prepare graphical content especially tailored to the shape of the projection surface. This will most often be created in a 3d modelling and animation application such as 3D Studio Max, Blender or Cinema4D to name a few. Here a complete 3D model of the chosen surface will be modelled with all visual details.
Considerations before planning a projection mapping
Since the content needs to be tailored to the exact shape of the building or the surface one cannot buy ready made loops for projection mapping. Although I have seen this advertised it is fake and will not create the desired illusion.
Projection mapping is a quite expensive form of entertainment. Apart from the cost of creating the graphics (and sound) there is also the cost of renting video projectors. If you’re projecting outdoors onto a building you will need one or more big projectors (15.000 – 20.000 lumen) and also take care that they are protected from the weather. This alone can cost up to 3000$ USD. However this will be cheaper for smaller surfaces.
Also light conditions will have to be taken into account so street lights may need to be turned off. The darker the environment the better or the real shape of the building will be visible and take away from the illusion one is trying to create.