...So what more features does this chipset contain?
Up The Rez
Ok, maybe you've heard some babble about 'super sampling.' Somewhere I read that the Katana would render internally at resolution X, then scaled to the correct output resolution for the monitor. This is super sampling. NEC defines it as such: Image is rendered to a specified resolution and then is scaled to the users view port using a bi-cubic filter (similar to Photoshop). The effect of the function is similar to anti-aliasing, except it works much better as the full scene is covered instead of specified edges. The PowerVR supports output resolutions of up to 1600x1200 pixels, and internally up to 2048x2048 pixels. The performance hit comes in a lowered fill rate, but not enough so that using the super-sampling vs. a higher resolution is slower.
Ok, so the chip does volume modifiers. What's that do for me? This feature is an extension to light and shadow volumes. Lets say you have two objects. A cloaked spaceship passing through a nebula of some sort. The spaceship is a regular object, while lets say the nebula has the volume modifier property. When the spaceship is inside the nebula, you can assign a graphic way in which it is effected. Say, its cloaking starts to fail when its inside, revealing the hidden ship. Here you'll see a volume modification demo with an x-ray effect. I've reduced the colors from full color to 64 to keep the file size down (3frame animated gif).
Chipset Arrival: Now To Developers, Summer '98 to Consumers.
Ok, so there you have it, the dEX PVRSG technology overview. I've left out some things, but you should be able to find more information on the source sites listed below. Later this week on May 21st, Sega of Japan will have a formal announcement regarding its next console. Then we shall see how this great chipset relates to the console.