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ArturNOW
07-02-07, 01:51 PM
Recently I bought NGC, ok like 2-3 month ago. I wanted to play some of the exclusive title like Super Mario Sunshine etc. I was playing LoZ: Wind Walker and I was surprised by the heat effect. Wasn't it untli DX 8 to see it on PC or am I wrong? As fas as I know GC's GPU doesn't have pixel shader capabilites... so have did they achieve this effect?

|MaguS|
07-02-07, 02:16 PM
It has Texture EnVironment which is ver similar to pixel shaders, basically it can accomplish the same effects through these.

ArturNOW
07-03-07, 01:23 AM
It has Texture EnVironment which is ver similar to pixel shaders, basically it can accomplish the same effects through these.
You just reminded me of Environment Mapped Bump Mapping with was able to symulate efect of hot air and produce other effect which were never catched by game developers on PC.

msxyz
07-03-07, 11:20 AM
You just reminded me of Environment Mapped Bump Mapping with was able to symulate efect of hot air and produce other effect which were never catched by game developers on PC.
EMBM is just one of the possible effects which are enabled by dependant texture reads.

You can do more than that. Heat haze, lens, specular bump mapping, water reflection/rifractions, procedural fire/fluids... just to name a few

Basically it's a multitexturing operation where the pixel values in the first texture are used to offset the texel coordinates in the second texture. EMBM, as described by DirectX, requires a third texture to be used as "diffuse" color but it isn't really necessary in a few of the other effects I mentioned

On the PC, it has been available since DirectX6 (1998) on the following 3D accelerators: PowerVR PCX2 (the PC version of the VPU used in the Dreamcast), the Matrox G400 and the first ATi Radeon. On DirectX 8 and newer hardware it's emulated through pixel shaders and made available as a "fixed function call" for backward compatibility

A shame it hasn't been used more often. Probably because both the TNT and the GeForce1/2/MX didn't support this feature (as well as having a lot of other things poorly implemented... but people seemed to care only about speed, back in the day)

Medion
07-03-07, 01:35 PM
PowerVR PCX2 (the PC version of the VPU used in the Dreamcast)

Just a correction. PCX2 was an update to PCX1, and was meant to directly compete with the Voodoo 1, Riva 128, and Rendition Verite. Neon 250 was the GPU based on the Dreamcast, and wasn't released until much later.

wollyka
07-03-07, 04:57 PM
PowerVR PCX2 that's bring old memories.. Half life 1 with OpenGL acceleration, Tomb raider 1, Hexen II ,MechWarrior 2 PowerVR Edition
They look sweet back in the days :)

Lfctony
07-03-07, 11:10 PM
Matrox M3D! My first decent 3D card! Wasn't too good though, lots of games, like Forsaken had massive rendering errors with these cards.

msxyz
07-04-07, 03:07 AM
Just a correction. PCX2 was an update to PCX1, and was meant to directly compete with the Voodoo 1, Riva 128, and Rendition Verite. Neon 250 was the GPU based on the Dreamcast, and wasn't released until much later.

Indeed, the chip was called the PowerVR PC250 or something like that. I got confused with the DC chip which was called the CLX2

It was an impressive accelerator, with full support of almost all DirectX6 features, 8 textures in a single pass, fast trilinear (when using S3TC) and dot3 + embm bump mapping. Feature wise, it was ahead of the competition, too bad it was released one year late with poor drivers. It wasn't until the Kyro II that it got its brief moment of glory.