Many shows today involve combining multiple layers of video content, either on a single display screen or across multiple screens of various resolutions. When you're working with a media server, there are some tricks that you can take advantage of to set up the scale, aspect ratio, and X & Y position palettes to reduce the need to resize your content ahead of time. Here is a little known feature available in the Mbox EXtreme v3 that can make programming easier. Alignment Rectangles
On a recent show, I controlled four different video display devices from two Mbox EXtreme v3 media servers, providing four separate video outputs. By using a separate video output for each type of display device, I was able to set up a master "size/scale" palette for each screen, and that reduced the amount of programming required just to get each of the six layers per output organized. Because of a feature called "alignment rectangles," I was able to map out the pixels on my local monitor as shown in Figure 1.
Once the rectangles are created and enabled from the control channel of the camera layer, then I can more easily size my texture (image) layers to fit within the borders of the alignment rectangles being displayed on my screen, as shown in figure 2.
{mosimage}In figure 2, I've created an image showing the pixel counts for the actual sizes of the display devices being fed from one of the video outputs, plus I've overlaid the alignment rectangles on top of the image to allow you to see the correlation between the rectangles and pixel count.
The next step would be to select one of the six layers and size it to fit within the boundaries of each of the rectangles, and that would ensure the image being displayed fits correctly on the display device.
Keep in mind that as you size any image up or down to fit within a definite boundary box like an alignment rectangle, you may have to distort the original image somewhat to make it work. There may also be some spillage of pixels beyond the boundary of the alignment rectangle, but you don't have to worry because those pixels won't be visible anywhere but on your local monitor.
Saving Layers
Alignment rectangles are an easy-to-use guide and a tool for defining the areas within your raster that you will be using to display content. They can be enabled and disabled easily from the control channel of the camera layer, making them as easy to turn on and off as a cue on the console. But by using these rectangles, you will not need to use one of your image layers as a master layer to map out the pixel counts and locations in the raster.
The alignment rectangles in the Mbox are created within the alignment rectangle editor shown in figure 1. This is an additional application within the Mbox utilities folder, and it comes with every unit. Once it is launched, I like to choose different colors for each of the rectangles to further help me identify where the rectangle appears on the display device. This also makes it a bit easier to more quickly tell when something isn't lining up right on the display screen.
The alignment rectangle editor includes a preview feature that makes it possible to see the rectangles on your local monitor with or without the Mbox application running. This handy feature means you can quickly see if the rectangles appear correctly within the raster before exiting the editor application. And because Mbox EXtreme v3 includes a variety of output screen configurations, the alignment rectangle editor also allows you to define on which output the alignment rectangles will appear when it is turned on from the console.
Simplicity Embodied
Multiple rectangle alignment files can be created, saved and edited from within the rectangle editor application. Once all of the necessary individual alignment rectangle files have been created, these files can be loaded easily via the Mbox remote application, a second utility application included with each Mbox, and they can then be turned on and off via the camera layer from your lighting console. Sound complicated? It's not really. More simply stated, you can create many rectangle files and then easily call them up using other tools and applications that are already available on your Mbox. It really is as simple as that!
Since media servers are so flexible, they allow previously-rendered content to be quickly and cleanly resized to match almost any type of pixel configuration of a display device. The alignment rectangle feature of the Mbox EXtreme v3 greatly simplifies the process of mapping out the pixels within the raster of a display device. Give this feature a try the next time you are mapping content to a display if it requires sizing and scaling, and you'll free up more brain-time to dream up creative visuals for the stage.
