Originally Posted by JunkoXan
the XBOX 360 did have tessellation functionality but it was never used as it was never efficient like todays hardware but it does show the 360 did have some DX11 compatibility but mainly was DX9 due to what i mentioned a moment ago.
Wind waker appears to just be using a simple discrete LOD technique, in which it swaps the water for lower LOD in certain cases. It definitely doesn't seem to be adaptive based on distance, the vertex density of the water appears to be the same at both near and far distance. The waves in the middle image are simply added on top of the water, they don't appear to become part of the water's geometry.
Here's a larger version of the image (if you click on this), which is a bit easier to see:Or click here for the full-size image.
Forms of tesselation, like CLOD (Continuous LOD) technique, have been around for quite awhile. It works like tesselation, but in many cases in games on older hardware it only works on surfaces that can be considered a heightfield. Heightfield means that for any given X,Z (horizontal) coordinate there can be only one defined Y (vertical) coordinate. Water planes and terrains in many games are implemented as a heightfield, for efficiency reasons, and any overlapping areas are often done using 3D mesh. Things like a land bridge for example would overlap terrain and thus would require a separate model.
Here's a good visualization of a chunked CLOD being used on terrain:
Similar to Wind Waker, the above images have geometry in the distance with more vertices than necessary. The water in Wind Waker is fairly sparse in terms of vertices though, so not much optimization was necessary.
In this example we can see that the terrain is using a technique that lowers detail of terrain chunks as they get further from the camera, however, they are not using a CLOD technique, so the terrain there are still sections of terrain that have a higher vertex density than necessary. This is easily noticeable because of the pattern of straight lines throughout the mesh.
It's pretty rare to find both techniques used together though, I couldn't manage to find a screenshot of both techniques combined. For most games usually one technique or the other is plenty.Edited by lordikon - 8/24/12 at 11:20am