Why do we need tesselation for curved surfaces?

[Tuna-Fish]

But that's missing the point. Why the hell use tessellation on mostly flat surfaces when you could use the tech on character and enemy models or anything else that could use the additional polygons. Why walls? Unless you're a fuzzy masonry affectionado, the 50-75% performance loss is insane.

The answer is really simple. Remember that it's not the early days of game design anymore when designer/programmers hand-crafted models polygon by polygon. Most models today are built by model designers who don't really even know what tech precisely renders their stuff. They just use the tools they are given, build a pretty model, and press export when done.

The tools that were used to make the assets for the presently available games were not designed to utilize gpu tesselation. As such, all the complex assets were built for traditional rendering methods. In contrast, a cinderblock or a cobblestone road is a very simple asset, and it's feasible for an interested programmer to hand-craft a prettier tesselated version to the game afterwards when tesselation is the new buzz and you want to get your feet wet.

Soon, (probably with the next console generation), GPU tesselation will become a feature that is fully supported by all the tools, and the designers will start making models with tools that use tesselation to render them.



Also, to all the people complaining that tesselation is not worth it and should not be used: Fundamentally, tesselation is just a method of compressing geometric detail. Nothing more. It could be used to make a game faster, by building the models to have less real tris and use tesselation instead. Or it could be used to render your cinderblocks with a million triangles. Right now, tesselation is not used very well -- but that's normal. It always takes a few product cycles for the industry to get a hang of a new technology. Also, because most of their customers don't presently have tesselation, it necessarily has to be a bolt-on feature, something that can be easily turned off without much fuss. So we get better cobblestones and pretty cinderblocks.

The next-gen consoles will support tesselation, and so when they become the main target that games are built for, tesselation turns from something bolted on to something that will be used for every model, by the model authoring tools.

 

[Kenmitch]

Man it would be nice if I could view the pics without ads splashing across the whole pic.

Or if they were mouse over to get a better comparison.