4D Projection - How it works
4D projection has taken the experiential, artistic and events world by storm in recent years.
It is an elusive and conceptional product that is frequently misunderstood. Here, SXS' Head of Special Projects Johnny Palmer explains.
First thing first: 3D or 4D?
These phrases are over, and mostly incorrectly, used. So let us first give definitions of each that help to have an overview of the subject.
Firstly, the "D" in 3D and 4D refers to dimension. The dimensions are Length (how long something is), Breadth (how wide something is) and Depth (how deep it is) and Time (which encapsulates movement, animations and anything else that requires time to occur).
As such, a drawing that depicts the width, depth and breadth of an object, such as a cube, is 3D as it is showing the three dimensions. Being the clever creatures that we are we will typically only be physically seeing two dimensions (on a computer screen, or piece of paper), but are able to percieve the third dimension of depth.
So, if this "3D" image was printed onto a piece of paper it is depcited in a 2D medium. Paper only has two dimensions: left to right and up and down. So it is fair to say that a piece of paper is a 2D medium but, due to our cleverness, we can interpret lines to make a 3D shape.
Hopefully that makes sense, and we understand that 3D images are not actually all that clever, but merely a drawing that depicts three dimensions. What might be a 3D image to us will probably be nothing more than a series of lines to a less intelligent creature, like a dog, pig or horse.
So what about 4D? You could argue that an image of a cube spinning around on a computer screen is 4D. It has length; it has breadth; it has width; and time is also used to create the impression of movement.
What about all this 3D Projection Stuff then?
3D projection is a set of technology used to give a more vivid and realistic impression of depth. See my full article about this here. 3D projection also gives a greater sense of Depth of Field and Parallax. If you want to learn more about this, I suggest Wiki:
And What About 4D?
So we saw earlier that all 4D imagery is really just an animation that gives the impression of space. However, people (including those in our company) have used the term "4D Projection" to refer to mapped projections onto flat planes that give the impression of physical movement.
Before I try to explain this rather abstract concept, I suggest you first watch this video to see some basic techniques in use:
This video was our first test of using these techniques in 2010 and we have subsequently done various projects for major international companies. Hopefully this will amaze you and give the impression that the building is lit up from multiple angles using different light sources. In reality the effects shown in this are all done with a single projector, staying in the same location throughout the demo.
The way this is done is by "mapping" the building in an animation program. This is first done by making a detailed 3D drawing of the building to work from. Once this is in the software unlimited effects can be created. For example, we can create (in the computer) the impression of a ball bouncing between the pillars of the building, or water flowing down the building.
Once this is created, it can then be "rendered" (see wiki article on this) and then projected back on the building.
It is interesting to see what is actually being projected. See the video to the right so as to see what is actually coming out of the projector lens. On your computer screen it will seem surprisingly plain. But click here to see what it looks like in real-life. This was a product launch for Virgin Media.
You will see from this that the lack of light is just as important as the presence of light. In essence it creates a form of negative space that tricks our conditioned interpretation of the images going into our brains.
At this point I would like to pay homage to some of the finest 4D projections I have seen, from some incredibly talented visual artists, see below:
Etienne De Crecy Live Performance
Inspiration, ground breaking and, once you figure it out, elegantly simple
Arguably the pioneers of 4D mapped visuals
How to Use This:
The SXS special projects team are here to help with bespoke and unsual projects, such as those requiring this kind of technology. Please contact us for more info here