When the opening of the new “Art Mall” shopping center was planned in Kiev, we were invited to participate as a studio of innovative technologies. The concept of the mall involves an art installation as the central content for the shopping space.
We developed a couple of interactive installations, but there still was a desire to create something really outstanding and large-scale. Then we offereded to transform a 1400 m2 gallery in a shopping center into a multimedia art space. We illuminated one wall of the gallery with 8 projectors to prove the concept, producing a small demo.
Engineering & optimization
The idea was gladly accepted, and we started to develop the project documentation. We aimed to map the walls and columns of the gallery with the maximum resolution and brightness possible, keeping cost-effectiveness in mind. We’d had experience of creating large-scale multimedia installations before, using a multi-projection setup. However, this particular project raised the bar. The projection was supposed to cover an area of 200 m in width and 3.4 m in height, resulting in an extreme resolution of 47,344 x 800 px, with a 60:1 video aspect ratio. In addition, the pixel density had to be much higher than in outdoor mappings.
60:1video aspect ratio
Preliminary calculations showed that we might need 50-55 projectors. Normally, so many projectors required the use of at least 5 powerful media servers. However, prior to this project, we already had the experience of connecting up to 32 projectors to a single media server. We used our proprietary Screenberry technology to create an immersive visual experiences for events and shows. Our innovative fulldome projects are powered by Screenberry technology as well.
Our engineers started looking for a way to connect all of the projectors to a single computer. In the beginning we designed a server architecture, which would support up to 64 projectors. We assembled a powerful server with a 6-core Intel processor, 32 GB RAM, SSD RAID array (3GB per second, yes we mean 3 gigabytes) and 2 latest NVIDIA Quadro GPUs (K6000) based on the Kepler technology.
GPUs were synchronized with the help of the NVIDIA Quadro Sync. We used 14 Datapath display wall controllers to distribute the video signal from 2 powerful graphics cards (with 8 outputs) to all 52 projectors.
8 output video cables connected to 2 graphics cards
2 latest NVIDIA Quadro GPUs (K6000)
Project setup in TouchDesigner
The next challenge was to make TouchDesigner play back files with such an extreme resolution. Just imagine, the video that we wanted to play had a 6,848 x 6,848 px (46.9 MP) resolution, and the output image would be 15,360 x 4,800 px (73.7 MP). We were unsure if TouchDesigner, although a versatile piece of software, could handle it. As we knew, no one had done it before. We installed the latest version, which supports 64-bit systems, and started experimenting with it. The support team was prompt and effecient in helping us with issues that arose in the process.
The next step was to configure GPUs. To achieve maximum performance and smooth video playback, we had to go through numerous combinations of settings and parameters. The output module in TouchDesigner was also reworked several times to achieve target performance. We heavily used Python, which was added in the latest version of TouchDesigner, to program the logic of the playback and calibration modules.
geometry slices for projection in the network editor
geometry slices for projection
scripts and configuration tables of the panorama
To achieve perfect projector alignment, the output pipeline included not only video playback, but also geometric distortion, blend effects and color correction, which were applied to the video stream in real time. After 2 months of fine-tuning and a number of experiments, we achieved a fully synchronized and smooth playback.
TouchDesigner UI mapped on the walls
Using the TouchOSC app on the iPad, we designed an intuitive UI to control calibration and playback.
screenshot with TouchOSC panel
TouchDesigner UI mapped on the walls
In this project we used ultra-short throw projectors with a 0.49 ratio, so that visitors would not cast shadows on the walls. However, the specifics of wide-angle lenses is that they have no zoom or lens shift. So each projector had to be mounted with centimeter-level precision. Exact technical drawings allowed us to hang the truss and mount the projectors correctly.
projector and cables
Video cables were also laid out in such a way that power cables would not cause interference. The total length of the cables exceeded 1800 meters.
Another step was to create a template for our video designers.Based on our projection layout tech drawing, we created a UV map where the exact position of each pixel on the map corresponded to the projected pixel on the wall.The UV map (or frame) had an extreme resolution of 6,848 x 6,848 px, or 46.9 MP for each frame. Furthermore, the total length of the video was 43 minutes or 64,500 frames, and thus we had to upgrade our file server, adding another 20TB of disk space and 10Gbit cards to the server and workstations to ensure an effective workflow.
UV template for video production
frame 6,848 x 6,848 px
In Front Pictures we call this process “spatial video design”. Unlike 3D mapping, we project the content onto a complex surface, which consists of a variety of planes with different angles. Not all of the surfaces are visible from all positions, adding another level of complexity to the process of content creation.
In addition to playback, we used TouchDesigner to create a virtual 3D stage where designers could preview their work in real time. They could move a virtual camera inside the set to observe the content the way visitors would see it from different angles and positions, while walking around. Our team and the client could experience “The Renaissance” even before the real gallery was actually built.
Virtual 3D stage (real-time preview):
Exhibition was opened on 29th March at Art Mall’s “A-gallery” and become a great attraction for the whole city. The “Renaissance: the Age of Genius” is getting a lot of positive feedback from visitors. The client was impressed and now we are working on the next big project – the “Alice in Wonderland” exhibition. Our tests have shown that we can successfully connect up to 64 projectors to a single media server, which will allow us to make the next exhibition even more spectacular!
Art Mall’s “A-gallery”