Any devlelopers using NV2A surface engine (for HOS)?

[Luminescent]

Are any games in development or out, which take advantage of the NV2A's surface engine? Brute force looks like it might but I'm not sure. Is the surface engine programmable or semi-programmable in any way?

Thankyou.

 

[JF_Aidan_Pryde]

Yes.

MotoGP uses a combination of Beize curves, patches and polygons for the bike construction. They say it helps with their LOD system. I wonder how they deal with the issue of pixel cracks etc. though..

 

[Guest]

PS2 SSX uses HOS.

 

[Luminescent]

JF_Aidan_Pryde, do you know if they use the XGPU to accomplish the effect, or is the tesselation done on the P3?

 

[DeathKnight]

The big secret is that for games, surface continuity actually doesn't matter very much. As long as there are no holes between patches (which is trivial to arrange), and as long as the normals point in more or less the same direction along the join, it makes no difference if they are slightly wrong. Minor visual errors can be corrected by averaging the normals from adjacent patches, and even though this is mathematically bogus, who cares as long as nobody notices? The only thing that really matters is whether you can build good looking and efficient models quickly enough to get the game finished on time.

http://www.gamasutra.com/features/20020626/hargreaves_pfv.htm

 

[MfA]

I think with fractional tesselation you can ensure no holes will appear even as you vary LOD between patches.

 

[Luminescent]

ERP, have you worked personally or know the effectivity of the surface engine on the NV2A? Is it a waste of silicon or is it useful for developers? Is it flexible in any way (read that it was somewhat programmable in an nvidia document)? Do you know of any titles that use it, if any (not sure about Moto GP)?

 

[ERP]

ERP, have you worked personally or know the effectivity of the surface engine on the NV2A? Is it a waste of silicon or is it useful for developers? Is it flexible in any way (read that it was somewhat programmable in an nvidia document)? Do you know of any titles that use it, if any (not sure about Moto GP)?

It depends...........

No I've never used it, but we did look at it at one point. It theoretically supports a wide variety of rectangular rational surfaces, with fractional tessalation at reasonable rates.

It doesn't work directly from the control points, so if your object is animating the control points it requires CPU intervention which can be expensive.

The main problem that we had, really didn't relate to the implementation, it was mostly authoring. In order to get the detail we wanted in the models we ended up with so many patches that just tessalating the control points was more than enough for display in most cases, making the extra overhead of the surfaces not worth while.

I could see it being useful in some circumstances, it wasn't to us.

I know of no titles that use it, but they might be out there.

 

[Lazy8s]

Seems like several snowboarding titles use bezier surfacing for the terrain. I remember that company, Housemarque (sp?) or something, saying their then-in-development Dreamcast snowboarding title was using bezier curves for the mountain slopes.