Date:
Sunday , April 25, 2004
Author:
Brent Justice
Editor:
Kyle Bennett
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Shader Model 3.0

NVIDIA recently distributed SM3.0 Screenshots and they got a lot of you asking questions. What was NVIDIA trying to show us with the screenshots from the FarCry game engine? We examine these differences and tell the truth about SM3.0.

continued...

The Bottom Line

It seems that most of the new features in Shader Model 3.0 are there to help performance, which is definitely a good thing. The new SM3.0 feature that we will likely see make a direct impact any time soon in gaming environment immersion is Displacement Mapping. Displacement Mapping can certainly add to an environment as shown in the NVIDA/FarCry screenshots, but for us to see those, the content developers have to be using those features actively. As you will see linked below, even this can be "faked" in SM2.0 to some extent, but even this is different from the effects that can be rendered with "true" DM.

Even game developers are unsure of the power of SM3.0 in realistic terms. This is what Tim Sweeney of EPIC had to say when asked about their usage of SM3.0.

We have some PS3.0 code up and running now, but since our access to capable hardware is quite recent, there's a lot of opportunity for further optimization and generalization.

But even though it is new and solid tangible results are not readily apparent, Sweeney lets us know that he thinks SM3.0 will be much better compared with what we have today.

We haven't made final decisions regarding performance and visual quality scaling between 2.0 and 3.0. But I expect that by the time Unreal Engine 3 games begin shipping 18+ months from now, any PS 2.0 hardware that is on the market today will be considered relatively low-end and run at reduced visual quality or resolution. Keep in mind that UE3 is designed for next-generation PC's and next-generation consoles, so the performance and feature set requirements are very high relative to today's hardware.

So what is the real bottom line here about SM3.0 and the rather misplaced NVIDIA comparisons that have been made public so far? If you are using an older graphics card not capable of supporting SM2.0, like any pre-GeForceFX NVIDIA or pre-Radeon 9500 graphics card, you are going to be in for an upgrade soon if you want to see all the eyecandy in the newest games. If your current video card will support SM2.0, like NVIDIA's GeForceFX or the ATI’s Radeon 9500 series and "better," currently nothing in terms of Shader Model quality is going to be revealed with an upgrade. Of course all this forgoes talking about better AntiAliasing, Anisotropic Filtering, and higher resolutions that play a huge role in gameplay.

We are happy to see NVIDIA pushing the envelope again and giving content developers newer and better ways of doing things. This is the first tangible "jump" that NVIDIA has had in technology over ATI in the desktop graphics market for quite a while. Undoubtedly, ATI's ground breaking DX9 cards gave them a foothold with their R300 VPUs and beyond. It will be interesting to see if NVIDIA being first with SM3.0 has a similar influence on the GeForce 6 series GPU. We know from past experiences, until the hardware is on the market, content developers will not widely implement the features and then sometimes it is still not readily apparent. Can anyone say, "Transform & Lighting?"

UPDATE:

Tech Report posted an interview with Tony Tamasi of NVIDIA and they comment on the FarCry SM3.0 screenshots and they make some statements that might lead you to beleive that no real SM3.0 operations are being done in the "PS3.0 Screenshots" from NVIDIA. We are a bit familiar with Virtual Displacement Mapping and Parrallx Mapping, but we were not lead to believe by our NVIDIA contacts that is what is going on in the screenshots from NVIDIA. And quite frankly it is not really that important. This seems to simply further our thoughts that SM3.0 is not bringing much in terms of Image Quality to the table currently that cannot be done in SM2.0 and that is what will be important to the gamers buying the video cards.

Going back and reading exactly what we asked NVIDIA, "What exact PS 3.0 features are (Crytek) using?" They responded, "As stated earlier, displacement mapping is used for the walls and stone textures like the Buddha." Funny enough, as noted earlier, Displacement Mapping is a Vertex Shader feature not a Pixel Shader feature. So all in all, I would have to believe what Tamasi is quoted as saying in the TR interview as true.

It seems that once again getting the exact truth out of NVIDIA can be a painstakingly complex exercise.

UPDATE #2:

PC Perspective has posted an interview with the CEO of the makers of FarCry. We found that answers to questions 7 and 8 fully support our conclusions on the subject we have put forth here in our article.

Q: 7) What aspects of the screenshots seen at the launch event are specific examples of the flexibility and power of Shader 3.0?

A: In current engine there are no visible difference between PS2.0 and PS3.0. PS3.0 is used automatically for per-pixel lighting depending on some conditions to improve speed of rendering.

Q: 8) Is the same level of image quality seen when using Shader 3.0 possible using Shader 2.0? If so, what dictates which Shader you decide to use?

A: In current generation engine quality of PS3.0 is almost the same as PS2.0. PS3.0 is used for performance optimization purposes.