In my recent experience designing for huge canvases (the sides of buildings) I have discovered many useful tips and tricks. The purpose of this article is to explore these discoveries with the intention of making 3D projection mapping designs more successful, especially for inexperienced designers.
The first thing that becomes apparent when looking at work on such a massive scale is speed. Designs and animation are initially created and displayed on a computer screen, less than 2′ x 3′. Even preview projections rarely exceed 20 feet across. Seeing the same sequences play out on a canvas several orders of magnitude larger, the speed at which events happen is greatly magnified. As an example, a 3D projection mapping project I designed and led covered all 4 sides of a 450 foot tall building. This represents an increase in size of more than 200 times, therefore elements and transitions that are dragged at a crawl on the computer monitor, move at a speed that seems unrelated when implemented on the computer. actual program. To look at it another way: moving 1″ on the computer screen (a fairly small distance relative to full screen) is equivalent to moving 25 feet – in a building this size, a fairly large distance for a viewer view from the Editorial transitions are subject to the same concerns: there is simply more information to process when such a large area of the field of view is active.
The solution is simply to change the aesthetic reference point in terms of time. What looks alarmingly slow on a small computer screen will be just fine when it covers the side of a large building. Some techniques can be used to help in this practice.
The first technique is borrowed from visual effects work for movies, especially 3D where pacing concerns are similar (for similar reasons). Make a real world scale reference in your preview window. An excellent addition to this, aside from the obvious measuring stick and local features, is the scale of human beings. A simple silhouette against the preview screen is very helpful. Using the zoom feature, preview the animation at various zoom levels paying attention to the size of the silhouette relative to your size. 1:1 will show the actual speed (things will often slide across the screen in an instant – nice to see), and 2:1 etc. it will give the impression of standing in the back of the audience with people in front of you. This approach can help using another technique (traditional 2D animators) – pantomime. Zoomed to various close ratios, learn the choreography as if you were pushing things with your hands, as actors often do with view screens in high-tech Hollywood movies. After learning the rhythm of the movement, you can get another preview aid by taking this ‘performance’ somewhere where there are very large buildings and ‘performing’ the choreography as if it were happening in the building you are in. in front of. Bringing your laptop or iPad along with the reference movie can help if remembering rhythms is new to you.
A second refinement can be added to this technique once a comfortable stimulation approach has been reached using the above technique. This technique involves the addition of sound. A click track (a recorded metronome used by musicians to stay in sync on overdubbed recordings) can be very helpful in establishing a ‘backbone’ beat. This will keep you “under the speed limit” so to speak, and has the added benefit of creating a graceful beat drive. If the click track is too monotonous, just use it as a reference to pick a rhythmic piece of music at the same speed. (For non-musicians, search for the term BPM.)
The other major area of concern in achieving quality in this type of presentation is contrast ratios. It’s disappointing (to say the least) that finely crafted images turn flat, gray and desaturated when viewed in context. The ideal approach is to have control of the ambient light at the presentation venue. In this highly unlikely and ideal case, one would simply keep all competing light sources off at show time, allowing projections to play in the equivalent of a dark theater. The realities of 3D projection mapping shows are quite different: rarely (if ever) does one get the chance to present their work in such a pristine setting. Ambient light sources are everywhere and cannot be controlled at all. There is probably nothing or your program that comes close to the deep blacks of your computer screen. In most cases, the contrast ratio of the program material needs to be adjusted to reproduce pleasingly in the context in which it will appear.
If possible, visit the performance site with a camera and take as many photos of the lighting conditions as possible. While photos will distort lighting conditions, they will be a helpful reminder of the sources and degree of ambient light present. Import these photos into your preview and use them for reference. Use them as backgrounds. Experiment with changes to the contrast of your program to make the material look presentable in this context. A great way to test and preview this, regardless of whether on-site photography is possible, is to do small-scale projections in poor lighting conditions. Try to preview in broad daylight or, if you’re indoors, with your work lights on. Finally, in the absence of any of these testing processes, play it safe and adjust the contrast ratio (levels in Photoshop) by ‘crushing the blacks’ as much as you can without completely destroying the images. This will also increase the saturation, but probably not enough. Then use Hue/Lightness/Saturation (also in Photoshop) to increase the saturation as much as possible without destroying the integrity of the images. Generally speaking, this is a situation where heavy-handedness will pay off: this is not the place for finesse or subtlety. If the above testing techniques are available, use them to make an AB comparison between the pre-color-corrected material and the post-corrected material. 9 times out of 10 you will find that the material is best presented with the blacks and saturation ‘squashed’ and no important subtleties will be lost. The elegance of 3D projection mapping is in the fitting of the material to the context (surface) and the choreography of the narrative: the actual projection itself is much more of an exercise in brute force and optimizing the program for the challenges inherent in the medium. allowing the finer points of the narrative, along with the inherent majesty and virtuosity of the medium, to be fully appreciated.
Bottom line: remember to keep the pace appropriate for the scale of the show. Set references for relative sizes and use a rhythmic audio device to gauge the rhythm. Check and measure contrast ratios whenever possible and use forecasts in difficult lighting conditions to check. Crush the contrast and saturation of your elements, and know that with these key principles in place, the inventiveness and spectacle of your show and designs will stand out without distraction.
Colin Miller August 2011