06.03 Projection Mapping Basics
Specialized projection mapping software offers the best solution for projection mapping, many graphics programs such as After Effects or Davinci Resolve, can be used to get started with projection mapping. Although After Effects, a general use motion graphics and visual effects program, is not intended for projection mapping, it can be used for simple setups with simple masking. Once you start using dedicated projection mapping software, animations and other video content used in the projection may still be created in a program like After Effects or Davinci Resolve, yet be projected via a dedicated projection mapping program.
Projection Mapping Setup
Projection Mapping Equipment
At a minimum a projector and a device to play media is required. In addition software to make content as well as make the map will also be needed. Then
Finding a Projection Mapping Location
Select a location with low light levels for projection mapping. This can be a controlled light situation indoors or outdoors at night. Indoor 24/7 emergency lighting and exit signs can potentially interfere with a projection. Outdoor street lights, car headlights and pathway lighting can interfere with a projection. Scout out a projection mapping location at different times and lighting conditions to best predict light interference and then plan around them.
Look at the surfaces. Are there more dark colors than light colors? Light colors work best. It is also a good idea to avoid high gloss surfaces that tend to reflect light. Solid, non-moving surfaces are the most predictable. Fabrics and translucent objects can create interesting effects but surfaces that move should be avoided for “ultra short throw” projectors to avoid image distortion.
Choosing a Projector for Projection Mapping
It is important to have a project with enough brightness and enough scale. To achieve brightness, a high lumens project should be used. The brightness of a projector drops the farther it is moved back from the projection surface. The inverse square law governs light “falloff” and the illuminating power of a projector diminishes quickly as it is moved back. Sometimes the only way to make a projection larger is to move the projector back with the consequence of less light. To avoid the need to back the projector away from the viewing area, projectors with a “short throw” should be selected. This projector distance calculator from Optoma can help determine throw ratios.
For large scale projections, multiple projectors can be synced together to cover more area with greater detail and brightness. Special software can handle the “edge blending” or the seamless overlap of the two projections.
Methods of Projection Mapping
Projection mapping content can be made with perspective baked in or it can be made as an head on, orthographic, view and then put into perspective with projection mapping software.
Basic 2D Masking
Setup the projector to project on the object or surface to map. Use software to mask out the parts of the scene that should not receive a projector. The benefits of this method are that it is quick and intuitive. The downside is that the projection mapping will just be a 2D image projected and won’t follow the contours and shape of the object.
Pseudo 3D Masking with More Surfaces
For simple objects, multiple masks and surfaces can be made to fit the different parts of the surface to be projected on. These ca nbe adjusted to “fake” 3D perspective and placement. The benefit is that it is still relatively fast but the downside is it is still limited by not have a full 3D representation and workspace.