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Nintendo Revolution: Displacement Mapping be the last key factor against PS3 & Xbox 360?
Is displacement mapping the last secret?
Browsing for more clues concerning the Revolution´s last secret, I came across the issue of displacement mapping, an improved version of bump mapping, if you will. This cropped up briefly in relation to the Nintendo Revolution some months ago, but I believe it has not been given enough attention. But before we go into that, let´s understand what this technique is about.
Why could displacement mapping be Nintendo related?
Firstly, there is a Nintendo patent that has caused this topic to crop up in this community before. It is entitled Method and apparatus for efficient generation of texture coordinate displacements for implementing emboss-style bump mapping in a graphics rendering system. Its abstract is a bit of a mouthful, unfortunately. Read my highlights, though:
A graphics system including a custom graphics and audio processor produces exciting 2D and 3D graphics and surround sound. The system includes a graphics and audio processor including a 3D graphics pipeline and an audio digital signal processor. Emboss style effects are created using fully pipelined hardware including two distinct dot-product computation units that perform a scaled model view matrix multiply without requiring the Normal input vector and which also compute dot-products between the Binormal and Tangent vectors and a light direction vector in parallel. The resulting texture coordinate displacements are provided to texture mapping hardware that performs a texture mapping operation providing texture combining in one pass. The disclosed pipelined arrangement efficiently provides interesting embossed style image effects such as raised and lowered patterns on surfaces.
This proves that Nintendo has not only been interested in this technique but is a patent holder. The section entitled ´cross-reference to related applications´ references 25 separate provisional patent applications that are thereby incorporated into the patent. Almost all of them date back to 2000. This would suggest that it is an important patent that has kept Nintendo busy but doesn´t date back too far to be cutting edge.
Secondly, relating back to making the process of displacement mapping more efficient and less of a strain on the CPU, one way of adaptive tessellation might actually be the last Nintendo patent I talked about in great detail, called Three-dimensional image generating apparatus, storage medium storing a three-dimensional image generating program, and three-dimensional image generating method. A number of readers pointed out that the patent had nothing to do with actually visualising graphics in 3D, but rather optimizing a 3D world to be viewed on a 2D display. Then, that patent made little sense to me. But in the context of trying to reduce the computational strain on the CPU involved in displacement mapping, this may make perfect sense.
Lastly, whether the Revolution´s graphics chip will turn out to be based on the R520 or R530, it will be Radeon technology. And its manufacturer ATI has the following advice for developers on their Designing for Radeon development support page: Use multi-texturing effects for realistic low polygon primitives. For example, you can use emboss style bump mapping to achieve the illusion of a bumpy surface that would take a lot more polygons to approximate otherwise. Similarly, other intelligent use of texture maps can reduce the polygon count of your mesh designs.
This may not be unusual, since nVidia will undoubtedly have similar advice on their development support pages, but at least it shows that ATI is also very concerned with this technique. In fact, ATI supported this technology earlier than nVidia, it seems. While the Radeon 9500/9700 was capable of displacement mapping, the GeForce FX was only partly so. The Radeon 9700 Pro already supported adaptive tessellation. In fact, ATI has an exclusive technology called ´Truform 2.0´, which is a kind of tessellation.
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