[hoom]

Does anyone know if the Dynamic LoD can auto-scale based on the frame-rate?

It would require a new benchmarking regime if every card would be able to play at 60fps just by scaling tessellation LoD

[rpg.314]

Yes tesselation can be scaled depending on the framerate. It is parameter under complete control of shader programmer.

[Voxilla]

Originally Posted by rpg.314

Yes tesselation can be scaled depending on the framerate. It is parameter under complete control of shader programmer.

Look what I did 6 years ago: http://users.belgacom.net/xvox/
Hardware only displacement mapping, even with trilinear filtering of the displacement maps.

If you press the A key, the continuous level of detail tessellation will be adapted so that the animation runs at 60 Hz on any card !

In wireframe mode you can see the tessellation pattern, slightly nicer than what ATI does if I may say.

[rpg.314]

Impressive, except all this tesselation was doe on CPU right? But I prefer doing them on a GPU, and that's why I am excited at dx11 tessellation.

[Voxilla]

Originally Posted by rpg.314

Impressive, except all this tesselation was doe on CPU right? But I prefer doing them on a GPU, and that's why I am excited at dx11 tessellation.

No, all tessellation is done on the GPU !
The CPU does very little work.

If you read the technical document you can find how it is done.
It is done with vertex morphing.
On my GTX280 I'm getting 400 million tessellated triangles a second.
Would be slightly impossible to do this with the CPU, especially as the mesh is not a triangle strip.

[fellix]

Kewl!
Adaptive performance LOD scaling -- The thing HW tessellation should be used for in future DX11 titles!

[Demirug]

Originally Posted by Silent_Buddha

I wonder if Dirt 2 will carry a redistributable Dx11 package?

There is no redistributable Dx11 package.

[Broken Hope]

Originally Posted by Demirug

There is no redistributable Dx11 package.

There sort of is one for Vista.

http://blogs.msdn.com/directx/archiv...ows-vista.aspx

[Demirug]

Originally Posted by Broken Hope

There sort of is one for Vista.

http://blogs.msdn.com/directx/archiv...ows-vista.aspx

I know. As we have a DX11 launch Title we were informed about this early. But this is not classical redistributable that you can put on a game disk. It’s more like a service pack.

[trinibwoy]

Hmm, that's a strange model to use for a tessellation demo. Giving bricks volume is fine but they already did that in Toyshop with POM. I expected them to use something with more fine detail, like a character or vehicle. I assume that's just one of several models in the demo?

[fellix]

This is just small part of the NDA-ed press material.

[Cypher]

Originally Posted by trinibwoy

Hmm, that's a strange model to use for a tessellation demo. Giving bricks volume is fine but they already did that in Toyshop with POM. I expected them to use something with more fine detail, like a character or vehicle. I assume that's just one of several models in the demo?

Actually, ATi showed a demo comparing the quality and performance of normal mapping v. POM, v. tessellation, and tessellation ended up being faster by a rather significant margin. Tessellation also looks better in the end as well, because you also have a different silhouette due to the tessellated surface; something you can't get with POM. Shadowing also ends up looking better, both in terms of receiving and casting because you end up dealing with actual triangles and not a funky raycast in a texture.

Look at these two, in particular:
http://img193.imageshack.us/img193/7131/00001z.png
http://img193.imageshack.us/img193/1281/00000w.png

I dare you to compare those two pictures and say "Enh, POM looks as good", because it simply doesn't.

[trinibwoy]

My comment was about the choice of model/effect used, not whether POM was better than tessellation.....

[Cypher]

Oh...well, it's not just bricks, you also have roofing tiles and such this time :P

[Voxilla]

Originally Posted by Cypher

Actually, ATi showed a demo comparing the quality and performance of normal mapping v. POM, v. tessellation, and tessellation ended up being faster by a rather significant margin. Tessellation also looks better in the end as well, because you also have a different silhouette due to the tessellated surface; something you can't get with POM. Shadowing also ends up looking better, both in terms of receiving and casting because you end up dealing with actual triangles and not a funky raycast in a texture.

I'm still wondering if they did anything new to boost the maximum triangle rate of small triangles. Tessellating to pixel sized triangles is fine, but if you can do only like 500 million triangles a second, you then also can do only about 500 million rendered pixels per second...
Shaders and backend must be running at less than 10% efficiency in that case.

[rpg.314]

It is likely that this gen or next gen gpu's will ditch the minimum 2x2 quad pixel shader runs, even for a pixel sized triangles to save useless pixel shader work.

[mczak]

Originally Posted by rpg.314

It is likely that this gen or next gen gpu's will ditch the minimum 2x2 quad pixel shader runs, even for a pixel sized triangles to save useless pixel shader work.

Given that simd width is much larger than that 2x2 quad anyway seems highly unlikely.

[DieH@rd]

Originally Posted by Voxilla

Look what I did 6 years ago: http://users.belgacom.net/xvox/
Hardware only displacement mapping, even with trilinear filtering of the displacement maps.

If you press the A key, the continuous level of detail tessellation will be adapted so that the animation runs at 60 Hz on any card !

In wireframe mode you can see the tessellation pattern, slightly nicer than what ATI does if I may say.

Excelent demo.

[Silent_Buddha]

Originally Posted by Voxilla

I'm still wondering if they did anything new to boost the maximum triangle rate of small triangles. Tessellating to pixel sized triangles is fine, but if you can do only like 500 million triangles a second, you then also can do only about 500 million rendered pixels per second...
Shaders and backend must be running at less than 10% efficiency in that case.

Well one of the main points for Tesselation was to increase the number of polygons that can be rendered per scene, so I can only imagine the maximum triangle amount will go up, obviously only when tesselating however.

Early tesselation demo's showed a quite radical increase in triangle count without a large performance hit up to a point. Unfortunately I don't think any of those demo's were made publicly available.

Regards,
SB

[Voxilla]

Originally Posted by Silent_Buddha

Well one of the main points for Tesselation was to increase the number of polygons that can be rendered per scene, so I can only imagine the maximum triangle amount will go up, obviously only when tesselating however.

One of the Siggraph papers elaborated on how the HW rendering pipeline would need to be modified to efficiently render loads of small triangles. There is quite a bit of work needed.

In my opinion it is not very likely that the R870 already would do so.

[Acert93]

While a lot of small triangles may not be efficient I wonder at what point you take that route only because it offers the most detail per pixel. Real geometry via displacement maps, even if a big performance hit, looks really nice compared to POM or normals, and if you are running at nearly 100fps anyhow why not take the hit for some real geometry?

[Voxilla]

Originally Posted by Joshua Luna

While a lot of small triangles may not be efficient I wonder at what point you take that route only because it offers the most detail per pixel. Real geometry via displacement maps, even if a big performance hit, looks really nice compared to POM or normals, and if you are running at nearly 100fps anyhow why not take the hit for some real geometry?

Sure, detailed real geometry is best, and with higher resolution screens the more you need of it. It hurts to see that even new games like Rage show angular curved objects.

[AnarchX]

5870: 157 fps @ Vantage perlin noise

[Lightman]

Originally Posted by AnarchX

5870: 157 fps @ Vantage perlin noise

Worth noting is that HD5870 scores were obtained on High preset! Makes it even more impressive

[AnarchX]

Feature tests are afaik not influenced by preset.