Segundo uma notícia veiculada na ReactorCritical, o novo chipset da NVidia não terá total compatibilidade com o DX9 da Microsoft, pela falta da tecnologia Displacement Mapping
21 November - Nvidia Strongly Dislikes Curved Surfaces: No Displacement Mapping Support in the GeForce FX
We were very astonished when Nvidia decided to turn off the parametric surfaces (or RT-patches in the DirectX parlance) support in their GeForce3 drivers a year ago. When asked why, Nvidia officials told that the support of curved surfaces should be turned off because several game developers implemented ATI’s TruForm technology in their games and the software decided that the GeForce3 accelerators also supported the N-Patches, whereas the GPU just tried to emulate them through RT-patches causing the performance to drop dramatically. Since the higher order surfaces are not used widely these days, their support is not something the end-users can take any advantages of, we forgot about this fact shortly after it had been revealed.
The higher order surfaces are here to allow game-developers to create very complex 3D-models without using too many triangles. There are many approaches of creating HOS surfaces, however, there are only two of them on the consumer market: RT-Pathes and derivatives and N-Patches in different incarnations. RT-Patches require control points definition over a surface at the stage of creating a model. Another way to achieve complex models and environments is to utilise N-Patches and its derivatives that calculate the control points on-the-fly. Since the latter were introduced by ATI, Nvidia said that they were not going to implement this in their own chips.
What is even more interesting is that they decided not to support Displacement Mapping technology from DirectX 9.0 due to unknown reason, according to sources. Maybe because the approach is based on the notorious N-Pathes?
Microsoft wants IHVs to support Displacement Mapping and points it out in every document they issue in regards DirectX 9.0. Both ATI Technologies’ RADEON 9700/9500 VPUs and Matrox Graphics’ Parhelia 512 graphics processor support the Displacement Mapping.
I now wonder if Displacement Mapping is “must be” function of the DirectX 9.0. If it is, Nvidia may not be able to claim the DirectX 9.0 full hardware support for the GeForce FX VPU.
alguém sabe dizer oq eh isso ???