tesselation factors in dx11
- Thread starter nobond
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A tessellation factor controls the amount of tessellation. It ranges from 0-64 and there are multiple factors per patch depending on the tessellation type. Quads have 6 and triangles 4.
A 3 control point patch with tri tessellation mode and all tess factors being 1 will just pass through the original triangle. As the number gets higher more triangles are created.
A 3 control point patch with tri tessellation mode and all tess factors being 1 will just pass through the original triangle. As the number gets higher more triangles are created.
Yes, but if one tess factors is 2 in one egde, there must be something else telling you where is the new vertex is. That is what I do not quite understand. In what way, the new vertex pos are being told to calculate in the dx tesselators.
While we are on the subject of tessellation, from what I've seen, why on earth did they choose that hideous fractional odd/even scheme. It seems to me that there are far better methods** which don't have the horrible swimming/wave artefacts. Is there some fractional methods available in DX11 that I've somehow missed seeing?
**e.g. I had such a scheme on MBX of all things.
**e.g. I had such a scheme on MBX of all things.
AFAIK, you can have fractional tess factors in dx11.
Yes, but do you only have a choice of "fractional odd" or "fractional even"?
I'm not sure what's special about differing tess factors. The tessellation factors are all you need to generate (u,v) coordinates for the control points. It's a fixed function algorithm so the (u,v)'s should be the same on all DX11 hardware. It's what the programmer does in the Domain Shader (DS) that determines the ultimate vertex position. The SDK should have a tessellation example if you're curious how a DS might look.
I guess what I should have said is "Is there no fractional_without_ugly_swimming mode"?
There's also power of two modes which should help, although I'm not sure if it's possible to blend between power of two subdivision levels without spewing one level out to emory first, which is a bit cack...
John.
