Games & N-Patches aka TruForm

[Goragoth]

Higher order surfaces (like TruForm) is problematic where shadows are concerned based on specific lighting solutions implemented in games. If shadows play a big part in a game, you don't want HOS. It fucks up shadow silhouettes. Better to spend the time using the good ole tradition (more polygons).

Care to elaborate? I know there are issues with current HOS implementations and all but surely a sensible design would allow shadows to be calculated after tesselation. I guess you are talking specifically about TruForm or other current HOS solutions. NWN has rather nice shadows though and I noticed nothing odd when TruForm was enabled.

More polygons won't last into the future but that was discussed in another thread already. I guess TruForm was a baby step into HOS territory, real usuage might come once we have a programmable tesselator unit and are no longer bound to a specific fixed function implementation.

Now I might go to try out the nPatches option in the UT2k3 ini file to see how unusable that is

 

[Ylandro]

The problem with shadows is ofcourse, that they probably don't receive the extra polygons. At least, in the current shadow techniques.
I actually don't see a good reason for it, but it's something you notice in the games.

I would imagine that shadow maps can use it without any problem...

 

[AlNom]

The problem with shadows is ofcourse, that they probably don't receive the extra polygons. At least, in the current shadow techniques.
I actually don't see a good reason for it, but it's something you notice in the games.

I would imagine that shadow maps can use it without any problem...

Bumpmapping/normalmapping sure doesn't help with shadows in Doom 3

 

[Rodéric]

The problem with shadows is ofcourse, that they probably don't receive the extra polygons. At least, in the current shadow techniques.
I actually don't see a good reason for it, but it's something you notice in the games.

I would imagine that shadow maps can use it without any problem...

Bumpmapping/normalmapping sure doesn't help with shadows in Doom 3

He is correct about Shadow Maps capable of handling truform just fine (being image space), while Doom3 Shadow Volumes can't since they are unaware of the additionnal geometry produced inside the chip.
So, I fail to see why you laugh...
Besides normal maps have nothing to do with proper shadowing (they are here for proper/enhanced lighting).
Parallax mapping is also an issue for Shadow Volumes and not for Shadow Maps.

 

[AlNom]

Bumpmaps/normal maps give the illusion of greater polygon counts to some extent. The models use less polygons. Stencil shadows adhere to those polygons. N-patches would make those models smooth. Shadows still remain the same. We no longer have pointy heads. laugh laugh laugh.

 

[Diplo]

Isn't the problem with TruForm simply that it isn't a standard? Why would developers spend too much time on a feature that will, at very best, only benefit half the target audience? Given the tight deadlines developers have they will probably spend the time on something that will benefit the majority of users unless, of course, an IVH can afford to give them financial and development help to implement the non-standard feature.

 

[AlNom]

Isn't the problem with TruForm simply that it isn't a standard? Why would developers spend too much time on a feature that will, at very best, only benefit half the target audience? Given the tight deadlines developers have they will probably spend the time on something that will benefit the majority of users unless, of course, an IVH can afford to give them financial and development help to implement the non-standard feature.

Well, N-patches is in the dx9 or dx8.1 specs (I forget) just not required..

 

[Diplo]

Well, N-patches is in the dx9 or dx8.1 specs (I forget) just not required..

Are they? Well, that shows what I know Still, the main point is that since they are not supported by a certain well known IHV then this sadly dramatically reduces their 'selling point' to developers.

 

[AlNom]

True

3Dc......it was worth a shot!

 

[jvd]

True

3Dc......it was worth a shot!

Just one big diffrence , 3Dc should have a better life , it should be in the new xbox and new nintendo system.

 

[Goragoth]

True

3Dc......it was worth a shot!

Just one big diffrence , 3Dc should have a better life , it should be in the new xbox and new nintendo system.

Also, as far as I can tell 3Dc should be a lot easier to implement for developers, since creating higher res 3Dc normal maps isn't much extra work (if you plan for it) while TruForm seems to have a lot of issues and you have to be very careful how you use it to prevent gaps appearing everywhere. Still, its always best for a technology if all major players implement it.

 

[Laa-Yosh]

Higher order surfaces (like TruForm) is problematic where shadows are concerned based on specific lighting solutions implemented in games. If shadows play a big part in a game, you don't want HOS. It fucks up shadow silhouettes. Better to spend the time using the good ole tradition (more polygons).

It isn't exactly so. The problem only exists if the tesselation of the shadow caster geometry and the rendered geometry is drastically different; but if you use only one tesselation setting, then it'll certainly be OK. Otherwise we wouldn't be able to do any CG here

 

[Scali]

It isn't exactly so. The problem only exists if the tesselation of the shadow caster geometry and the rendered geometry is drastically different; but if you use only one tesselation setting, then it'll certainly be OK. Otherwise we wouldn't be able to do any CG here

Actually, even without exact tesselation, you can make shadowvolumes work: http://www.gim.ktu.lt/nesnausk/nearaz/texts/revext.html

I suppose this would also work with TruForm on for the scene and off for the shadowvolumes...

 

[AlNom]

Just one big diffrence , 3Dc should have a better life , it should be in the new xbox and new nintendo system.

Oh yeah! I completely forgot about 3Dc for consoles.

So is the compression ratio about 4:1? So we could fit 512x512 in the same memory space of uncompressed 256x256 normal maps?

 

[DavidGraham]

Sorry for bumping a decade old thread , I got my hands on C&C Renegade , I couldn't enable curved surfaces (TruForm) on my GTX 660Ti nor HD 6770 , so was the support for the technology dropped from modern AMD GPUs ? If so ,Can it run on software mode then ?

 

[milk]

Sorry Gaham if you came here expecting an answer and all you got was this stupid post of mine, but I couldn't help finding this thread amusing. I re-read the thing from beggining to end (barely two pages...) and started thinking, gee, is that what all the tessellation related talk is gonna look like ten years from now?

 

[3dcgi]

I don't think Nvidia ever supported tru-form and I think ATI dropped support long ago. Technically all AMD parts over the years have been capable of n-patch support though some of the finer details may have changed.

 

[DavidGraham]

gee, is that what all the tessellation related talk is gonna look like ten years from now?

Hopefully not. Tessellation is now supported across multiple generations of GPUs and a console generation too , it is also an integral of DirectX , is a standard feature in many games now. TruForm had none of that .

think ATI dropped support long ago. Technically all AMD parts over the years have been capable of n-patch support though some of the finer details may have changed.

Then why did they drop the support? I think maintaining it is a trivial task.

 

[Davros]

Because some idiot at amd decided that you no longer want to play C&C Renegade or Return to Castle Wolfenstein or Neverwinter Nights or any of the other games that support truform

Mr bauman if your listening next time one of your engineers say "Hey gamers no longer need feature X, lets remove support for it", will you kindly grab them by the throat and slap them silly...

Your only hope may be nick with his SwiftShader, but he doesnt seem to be interested in adding support for earlier versions of directx so i cant see him adding truform support either

 

[3dcgi]

Hopefully not. Tessellation is now supported across multiple generations of GPUs and a console generation too , it is also an integral of DirectX , is a standard feature in many games now. TruForm had none of that .


Then why did they drop the support? I think maintaining it is a trivial task.

Most things aren't trivial and the implementation details are different now. IIRC it was only really ever supported with R200 and R300 had a software implementation. Probably when new hardware required a new driver branch TruForm support was lost completely.