What is the difference between Projection and Pixel Mapping?

Pixel Mapping, is simply the process of applying an image, motion image, or video to a group of fixtures. We are familiar with pixels on something like a TV. Look close enough and you see that your picture is made up of tiny dots which as a whole, make up your video that you watch.
pixel_houseWell this can be done with any group of lighting fixtures as well.

la back 1So let’s say if we make a grid of 10 lights wide and 10 lights high. That would require 100 lights to create ten rows across and ten rows high. Now we can lay that grid out in software like we find in many of the lighting consoles or in media servers. You only recreate the grid and then it is possible to feed video to your array of fixtures in this case. You can of course even spell out letters and more just by using your pixel grid.

Watch this video to see some students playing with simple pixel mapping on Source Four Pars.

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. By using specialized software, a two- or three-dimensional object is spatially mapped on the virtual program which mimics the real environment it is to be projected on. The software can interact with a projector to fit any desired image onto the surface of that object.

After the object which will be projected on is chosen or created, a virtual replica of the entire physical set up needs to be created. First, one must choose the images or video to project. Then, the virtual model of the projection surface is created within the computer using special programs. The next step is defined as “masking,” which means using opacity templates to actually “mask” the exact shapes and positions of the different elements of the building or space of projection. Coordinates need to be defined for where the object is placed in relation to the projector. Finally, the xyz orientation, position and lens specification of the projector add to the virtual scene.[6] Adjustments are commonly needed by manually tweaking either the physical or virtual scene for best results. Large projectors with 20,000 lumens or larger will be needed for large-scale projections such as on city skyscrapers. Otherwise, for smaller productions, a projector with a basic lower lumens will work. Video mapping software such as MadMapper and VPT 6.0 are all downloadable for use in projects like these. Also, extensible open-source software frameworks such as MPM (Multi-Projector-Mapper) are available.

Don’t be fooled though, this of course is still not a true 3D presentation. A true 3D image is typically holographic in nature. Although some other interesting illusion based processes are still widely used out there. One in particular involves the use of transparent screen material that is projected on with hidden projectors. This gives a very good illusion of an almost 3D object or person. An example of this would be the Tupac appearance (after his 1996 death) at the Coachella festval. Everyone refereed to this as a holographic image when in fact it was just another use of the basic peppers ghost effect in a more modern scope. Rather than glass the Tupac performance uses a proprietary Mylar foil, known as Musion Eyeliner.
tupac-snoop-4f8cb6e-introWatch the Tupac video here if you missed it. (WARNING – This Video Contains Foul Language)

Here is a video showing the very basics of doing video mapping to help illustrate how the video mapping process is accomplished.

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