Paul Rajlich
Research Programmer
Visualization and Virtual Environments
National Center for Supercomputing Applications 		prajlich@ncsa.uiuc.edu
http://brighton.ncsa.uiuc.edu/~prajlich/
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me on top of mini-wall

Recently, we built a 5x3 mini-wall for TRECC using 18" NEC lcd panels. The panels are mounted onto an aluminum structure designed by Albert Khakshour that also holds the cluster of 16 PCs (MicroATX form factor, aluminum cases). The unit is on wheels for easy movement.

We arrived at the current configuration for the following reasons:

  • With an odd number of panels in both dimensions, the center of the display is a tile, not a border.
  • The 15 PCs plus the head node make a total of 16 machines. This allows us to use one 16 port gigabit-ethernet switch. The switch is tucked away in the back.
  • With the individual panels turned on their sides, the overall display resembles a paned window and has a nice 4:3 aspect ratio ( The aggregate resolution is 5120x3840).

    My job was to make the software from our projector-based tiled wall work on the mini-wall as well. I made small changes to my movieplayer (npb) to allow for rotated tiles. I also created a Chromium configuration to simulate the "paned window" effect. Basically, the borders between the panels are represented by hidden pixels in the final rendering window. This means that parts of the final image are "occluded" by the borders and are not displayed. As a result, it looks like you are looking out of a window rather than seeing a bunch of disconnected images.

    Here are some pictures of the mini wall.

    We took the mini-wall to SC 2002 and the reaction was very positive. Based on my experience, using lcd panels for a display wall works well with some content and not so well with other content. Specifically, content that has rectilinear features in it does not work well with the panel borders. With other content, such as the movies shown in the pictures, it works great. It really does feel like you are looking out of window.


    new VisWall-LCD - the mini-wall revisited.


    • (C)opyright 2003, Paul Rajlich       Want to see what I am doing now? Visit www.visbox.com


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