To welcome the new year, I thought we'd look at the burgeoning activity surrounding image projection on building façades. But first, let me direct a few seasonal words to our friends in the WorldStage e-mail community.
2010 provided us with many opportunities to appreciate the important things in life - friends, family, good health and happiness. At WorldStage we are thankful that we can count our many clients and colleagues as friends and family and we hope you've enjoyed a safe, happy and relaxing holiday season.
Josh Weisberg
President, WorldStage
To The Wall
As the amount of building façade projection work we're seeing continues to increase, so it seems does the amount of confusion related to what is façade projection and what is actual 3D mapping. The difference is important because one objective requires a totally different set of design and implementation parameters than the other.
When It's Mapped & When It's Not
In broad terms, mapping a façade entails creating media that specifically accounts for the architectural elements of a building façade. In addition, if any of those architectural elements create a new plane, by extending inward or outward in respect to the majority of the façade surface area, then we can extend the definition and say the surface is "3D-mapped".
To illustrate, let's look at three example. The first is a flat façade projection where the media only takes into account the height and width of the façade - there are no architectural details that link the media to the façade. All the building detail is contained within the media, which very effectively creates the illusion of building wall transparency, allowing the viewers to see "inside" and witness the activities of the fictitious occupants.
The second example, which was created using scale models of real buildings set inside a convention center, illustrates 2D mapping of media to specific architectural elements. This means that the content was created using a two-dimensional map and the projectors were aligned and geometrically corrected so that the windows, doors, cornices, etc, were coincident with the projected media.
Finally, the third example illustrates façade projection with extensive 3D mapping. In this example, you can see where the content and the projector configuration use the depth of the architectural elements, along with their height and width. Since some of these elements contain more than eight feet of depth, the mapping is somewhat involved.
What Flat Façade, Mapped Façade and 3D-Mapped Façade Mean to Content Development
Flat façade projections, or façade projection that ignore architectural elements, need not require special attention since the display environment can be considered a standard flat projection screen. We still advise that content developers pay attention to light levels within the image to ensure that the visual energy is high enough to standout against ambient light levels or a façade that sucks up projected light such as dark brick.
Compared to a flat façade application, a mapped façade requires that content be developed very precisely, but still only in two physical, versus virtual, dimensions. The required precision can be attained by using a detailed map that shows the exact size and location of the façade elements. In these circumstances we create a pixel map that shows where the elements are within the projected image and the precise size of those elements.
For true 3D-mapped applications, an accurate 3D model is the starting point for content design, manufacture and implementation. Hopefully, the accurate 3D model already exists and can be utilized. If not, it may be worthwhile to hire a 3D architectural mapping company to create a 3D model using laser scanning tools. Alternately, it may be possible to create a 3D map by extruding façade elements from a 2D elevation - although that can be risky and the resulting map should be checked against the physical site.
Why the Content Matters More
Having been involved with a number of façade projection projects and having looked at many others examples, one of the aspects we've noticed is that content projected on building facades carries an additional burden, compared to standard video presentations. Because this video content is situational and exists in tandem with the architecture, it must support the context effectively.
Just like a 3D movie, façade projections must show the justification for the special effect, otherwise it's just a movie displayed on the wall of a building. On the other hand, a façade projection that relies solely on gimmicky effects and lacks a healthy dose of wit, humor or drama can be lifeless. However, content that effectively integrates visuals with building architecture or environment in a compelling and interesting way can really make an event a memorable experience.
