some more info about NVIDIA AR10 ("GoForce3D")

To add to that, a reliable source has told me that, at a recent conference, Sony were explaining that their curved surface implementation can actually have cracks between the tessellated triangles.

"Nice".

 

that could come useful 8)

 

OK, I'll bite. Even I can't think of a perverse use for that sort of "bug art".

 

I can confirm your source is reliable

 

Well the other stuff I've seen was either too dark or not worth mentioning. The "Death Jr." video to be found here:

http://zdmedia.vo.llnwd.net/o1/Death_JR/deathjb.zip

...was the only one that looks acceptable. I don't even know the game, if it's an older port or a new one.

Sony was explaining that they have cracks? It's a feature, not a bug. Quick get gaps in your implementation too

 

So when will cracks appear? Just when using fractional tesselation for continuous detail or in general?

 

From what I hear they can not have different levels of tesselation on different patch edges. So when 2 patches touch each other and one has a higher level of tesselation than the neighbouring patch then they will not line up, you effectively get cracks between the 2 patches. AFAIK there is also only integer tesselation levels not fractional. Then again I hear a lot...

 

Sony tells developers to use the same LOD for all the patches in a game character (so no cracks here) and to clear the screen with a 'fill' color to prevent seeing cracks in tesselated landscapes.

ciao,
Marco

 

Well there was a bug in an earlier version - perhaps I can resurrect it from the version control system.

I'm led to believe it only has integer LOD and that is fixed across each patch, hence you get cracks if you try to vary the LOD across the model.

Edit. Ah I see K already answered.

 

That would seem to be an artifact for any HOS implementation.

 

Errr... no... you just need to support different tesselation levels for each patch edge. If you want to support depth-adaptive techniques this is quite essential.

K-

 

Oh, sorry, I misread your post. Wow, yeah, that's pretty limiting that you have to have the same level of tesellation on all edges of the same patch (I was solely thinking of neighboring patches).