Why not much info/buzz about Real Time Tessellation?

[Dr. Ffreeze]

Hello Beyond3D! =)

I have often wondered why we don't see more Real Time Tessellation in PC games. I have seen many in depth articles on Bjorn3d, and I would really enjoy such an article.

To further the scope of the article, you could also discuss various ways that current and future games and video drives scale up and down real time depending on the work load. I remember seeing something about Real Time Tessellation from Valve (Team Fortress II?), Carmak (Trinity?), and Intel, but I am not sure how much it is being used in today's games.

I would really like to use as close to 100% of my video card's power in my games without hitting the dreaded st-st-stutter. I see no need for 300+ FPS. What is being done to achieve this (if much of anything)?

Dr. Ffreeze



--- QUESTION ---
Also, I do not understand why ATI and NVidia don't just put a setting in their drivers like: "Min Desired Frame Rate". In the most basic of implementations, you could monitor the Frame Rate, and just scale Ansiotropic Filter up and down real time.

If Measured_Frame_Rate < Min_Desired_Frame_Rate
Then Anisotropic_Filtering = Anisotropic_Filtering - 1
Else Anisotropic_Filtering = Anisotropic_Filtering + 1
-----------------------

Dr. Ffreeze

 

[Dio]

'Reactive' methods of tweaking framerate tend not to work particularly well - you end up making a choice between slow reponse to rate spikes and oscillation between two states. Predictive methods work much better, but would be very hard to implement at the driver level.

Sudden changes of IQ features can also be quite visually disturbing. If there was enough demand for it though, I guess it could be considered...

 

[Dr. Ffreeze]

Dio,

I guess I would just like to be able to play my games with the most visual quality that I can without ever getting below a Min Frame Rate. When I start playing a new game, I fire up the game, fire up FRAPS the play in a few areas. Then I parse my FRAPS data into Excel and get a feel for the Average Frame Rate and Min Frame Rate. I then increase or decrease settings.

K.I.S.S! MAN I would love to get max quality without havinging to do all this work. I would think someone would be able to fix this issue?

Any thoughts?
Dr. Ffreeze

 

[ET]

Well, what you do is certainly something that seems too much for a driver to do. You're asking a driver to note frame rates for a run, then "get a feel" for the average and minimum frame rate, and then adjust settings accordingly. That's quite a bit of not too well defined work. That said, perhaps an application could be written to automate this.

 

[KimB]

Hello Beyond3D! =)

I have often wondered why we don't see more Real Time Tessellation in PC games. I have seen many in depth articles on Bjorn3d, and I would really enjoy such an article.

It is necessary to have higher-order surfaces support before realtime tessellation becomes very useful. It can be done on the CPU, but it's not terribly easy to program for, and it sucks up cycles. With current hardware, it's typically much faster to not bother with realtime tessellation, but instead just store static geometry (or, sometimes, multiple models at different LOD's).

Once we HOS come into use, however, real time tessellation will become trivial to support, and it should also look very good. Current rumors indicate that the NV40 (which is planned for release this Christmas) will support a programmable primitive processor, which promises to provide robust HOS support (we've had HOS support in the past, but games have typically not bothered to support the various techniques available currently because they're just, well, very poor for one reason or another).

 

[Hyp-X]

The first card with adaptive tesselation is the Parhelia.
Sadly it's still the only one.

 

[Riddlewire]

Didn't Messiah and Sacrifice both use realtime tessellation pretty effectively? ("effective" in terms of framerate; there were obvious popping effects in Messiah)

 

[Arun]

Well, what you do is certainly something that seems too much for a driver to do. You're asking a driver to note frame rates for a run, then "get a feel" for the average and minimum frame rate, and then adjust settings accordingly. That's quite a bit of not too well defined work. That said, perhaps an application could be written to automate this.

Actually, AFAIK, some games already automate it.
Grand Prix 4, for example, got a basic automation system for this, but IMO, it isn't very efficient. Although it certainly gives you a better basis than doing everything by hand!


Uttar

 

[ET]

It does make more sense as part of the game. That's partly because games can use LODs, which would be next to impossible to do in a driver. The range of optimisations a driver can do is not that great, and certainly making the drivers faster and more stable and compatible would always be more important to the drivers developers.

What I was thinking about is an application like FRAPS but that also analyses the performance data, and allows running games through it with optimal options.