There's a new trend in architectural lighting and projection involving the use of projectors fed by digital lighting media servers to illuminate the facades of buildings both for entertainment and advertising purposes. Media servers like the Green Hippo Hippotizer and the Barco High End Systems Axon have been used in some of these projects because they offer 3D surface mapping functionality. And because these media servers are capable of being controlled via a DMX lighting console, it's becoming more common for lighting programmers to be involved in these projects. So let's take a closer look at 3D mapping features of the Axon and Hippotizer. What is 3D mapping?
A media server with 3D projection mapping allows images to be manipulated and distorted across multiple points. This means that any image can be morphed and shaped for use on a 3D surface so that it will appear flat on a curved or 3D surface. Using a media server that has 3D surface mapping functionality also means that the programmer has more flexibility in the mapping to curved surfaces than would be found just projecting a 4:3 image on an uneven or irregular surface. Recent examples of architectural projection applications include the Fourth of July celebration at the Palms Resort & Casino and the Tropicana Casino, both in Las Vegas. Both resorts have recently experimented with this eye catching and exciting way of getting their messages out to the public. (For both of these applications, the HD content was created specifically for the client by TVP, a Houston-based video production company.)
Projectors
The first step in architectural projection is choosing the type and number of projectors needed to cover the projection area. When you use multiple projectors, you should take care and pay close attention to the positioning of all projectors in order for 3D surface mapping to be successful. Equal angles and position heights of the projectors are extremely important, because this will minimize the amount of keystoning in the projected image. The lens size is also critical to make sure the image utilizes the maximum number of available pixels in the image.
Axon and DL.3
The Collage and Spherical Mapping features of the Axon media server allow standard rectangular video output from the media server to be wrapped on a section of a curved or irregular surface using DMX channels on a lighting console to manipulate it. Some of these image control channels include controls for the vertical position of the projector, the vertical position of the 3D object, vertical size, the amount of vertical bend in horizontal lines, the vertical center of the added bend and horizontal size.
Here's a tip for if you are working with spherical mapping or aligning a collage with the Axon or multiple DL3 units: when you are setting up the projectors for a multiple projector project, it is very helpful to project an alignment grid onto the 3D surface so that edges, sizes and angles can be matched between each one. Once the positioning of each of the projectors has been set, it is necessary to align the centerline of the alignment grid with the center of the 3D surface. Since this is a media server, the image can be easily adjusted up or down using a DMX control channel. Once the vertical lines of the alignment grid are aligned with the vertical axis of the 3D object, the image can be moved to the desired area of the 3D surface, again using a DMX channel.
Essentially, once the projectors are aligned physically, the projected grid will need to be blended across the multiple outputs using the designated DMX channels for edge blending. Once edges are blended, any image selected from the library will be distributed across the multiple outputs and will be "mapped" to the 3D surface based on the settings for mapping channels including latitude, longitude, vertical and horizontal center and bend. All of these settings are accessible from the lighting console and are saved into the lighting cue as any other DMX channel value is stored.
Hippotizer
The Hippotizer's Screen Warp is a unique component of the Hippo software and is accessible from within the main Engine Master screen. In the Screen Warp Manager, warps are created according to the size and/or shape of the 3D surface. Control "nodes," or handles, can be added to the warp's grid and are necessary to manipulate the grid to fit on the non-linear surface. These warps can be easily saved and recalled in the Screen Warp Manager. And in applications where multiple servers are being used to create the completed projected image, Screen Warp also allows soft-edge blending around the perimeter of the warped area via controls for blend left, blend right, blend top and blend bottom. Gamma and overlap controls are also available for each side of the warp and are used to create the seamless blending of adjacent warps.
Both Axon and Hippotizer are easily configured and programmed, opening up the world of architectural projection to lighting designers. This new area of convergence between lighting and video is becoming an exciting new way of reaching new audiences for hotels, conventions and concerts. And with the rapid and advancements in projection technology, this style of advertising has the potential to become much more entrenched in the marketing budgets of many types of businesses.
For more images of 3D mapping applications, please visit
http://tvpmedia.com/jack_hattingh/167272.
