Big Pictures, Little Packages.(Technology Information)

NEW 3D COMPRESSION TECHNOLOGIES STRIVE TO ENABLE NETWORK-BASED DELIVERY OF COMPLEX MODELS

The challenge of compressing large or complex 3D digital models into a package small enough to be delivered quickly, efficiently, and unscathed across networks is easy to conceptualize.

In the everyday world, people are constantly trying to squeeze big things into small spaces. Consider the hapless airline passenger struggling to get a much-too-big carry-on bag into the much-too-small overhead compartment. The luggage will be squeezed, squished, turned upside down and right side left, its contents will be reconfigured, and some of its items will be removed. Ultimately, the passenger might hear the triumphant click of the hatch, but such success comes with a price. Not only might the duffel be horribly misshapen, the contents will likely be wrinkled, cracked, or otherwise traumatized, and the effort itself will have caused a bottleneck of passengers.

The same can be said for 3D models. There are many ways to manipulate the digital data for successful transmission across networks constrained by today's bandwidth limitations.

For example, information can be removed from the original file in order to reduce its size, the framework of the geometry itself can be altered to approximate the original shape using fewer bits of data, or the entire model can be delivered in progressive stages to prevent network bottlenecks.

However, each option has some undesirable consequences. Either information is lost and must be re-created on the receiving end or the shape has been somehow corrupted by geometry alterations or the delivery time for the fully detailed model is too slow.

The compression problem is exacerbated by the fact that advances in desktop graphics capabilities have far outpaced gains in network capacity. So while the models being created are getting ever bigger and more complex, the delivery channels they're being shoved through are not expanding proportionally. Similarly, until recently, available compression technologies have concentrated on small polygonal models, so they've been ill-equipped to handle the higher-quality models being generated even on low-end PCs. Instead, they result in large files and long download times before the first image can be rendered.