Re: Interesting article, but...
"It's a technique that allows a single polygon to simulate multiple smaller polygons with a smooth gradation between the joins.This allows a model to appear to be high-polygon when it is in fact relatively simple and low-polygon.
What's more the technique is open and as such is widely used. Blender includes it as a modifier"
Blender may use Catmull-Clark as a method to decide how to subdivide faces but it doesn't "simulate" the additional smaller polygons to make a model "appear" like it has a high polygon count as your post would suggest; Subdivide a simple cube 4 times with Subdivision Surface and you'll end up with a sphere (of sorts) with 1,536 faces. All those extra faces are there as if you manually created them. Catmull-Clark, or at least it implementation in Blender, isn't some visual trickery, like Smooth Shading, to "simulate" the "appearance" of extra detail. The editable verts/edges/faces do become something more akin to "handles" on curves in vector based image editors but you don't get the look of a high polygon model without the extra CPU/GPU overheads that brings.
What I'm more impressed with is it appears that some games are now using live Catmull-Clark subdivision (slightly edited to keep edges without adjoining faces always sharp) on their models in certain circumstances where there is less going on (like in menus or photomodes) and they can afford to significantly bump up the per-model poly count. It wouldn't surprise, on the next gen of consoles, if we start to see live Catmull-Clark subdivision in many more (playable) areas of games since, as well as making lower poly models look better, it also effectively acts as a form of "compression" in a similar way as vector based images do compared to a bitmap based image for certain types of images.
Biting the hand that feeds IT
