[vtkusers] vtkQuadricLODActor and NumberOfDivisions?

[Arnaud GELAS]

Bill, David,

Thanks!
Changing the frame rate reduces the number of polygons and I can see a 
real difference.

I am trying to render more than 10 000 meshes made of few thousands 
polygons. These meshes (objects) are all different and can not be merged 
into a single one.
I have tried using vtkQuadricLODActor in my application (even with a 
extremely large frame rate), but it is really slow and it is almost 
impossible to rotate...

I guess I'll give a try vtkLODActor and vtkLODProp3D.

Am I going the right way? What would you recommend?

Arnaud

On 02/06/2010 08:17 AM, David Doria wrote:
> On Fri, Feb 5, 2010 at 11:36 PM, Bill Lorensen 
> <bill.lorensen at gmail.com <mailto:bill.lorensen at gmail.com>> wrote:
>
>     I looked at the source of QuadricLODActor. It controls the number of
>     divisions. Even if you override the divisions in the LOD filter, it
>     changes them to what it thinks they should be. It  Apparently this is
>     not a bug. It is a design decision. There is an algorithm in the code
>     to pick the number of divisions based on the desried frame rate.
>
>     On Fri, Feb 5, 2010 at 12:47 PM, Arnaud GELAS
>     <arnaud_gelas at hms.harvard.edu
>     <mailto:arnaud_gelas at hms.harvard.edu>> wrote:
>     > Bill,
>     >
>     > I have just tried, but I can not see any difference...
>     >
>     > Arnaud
>     >
>     > On 02/05/2010 08:32 AM, Bill Lorensen wrote:
>     >>
>     >> Arnaud,
>     >>
>     >> There is AutoAdjustNumberOfDivisions which defualt to On. Try
>     to apply
>     >> AutoAdjustNumberOfDivisionsOff()
>     >>
>     >> Bill
>     >>
>     >> On Thu, Feb 4, 2010 at 4:55 PM, Arnaud GELAS
>     >> <arnaud_gelas at hms.harvard.edu
>     <mailto:arnaud_gelas at hms.harvard.edu>>  wrote:
>     >>
>     >>>
>     >>> Hi guys,
>     >>>
>     >>> It seems that the number of divisions used by the clustering
>     method is
>     >>> set
>     >>> to a default value, and can not be modified.
>     >>> Is it a normal behaviour?
>     >>>
>     >>> I attach one example, that I was going to submit on the wiki,
>     where you
>     >>> can
>     >>> (theoretically) change the number of divisions for the
>     clustering method,
>     >>> but I can't see any difference...
>     >>>
>     >>> Arnaud
>
>
> I tried to set the framerate extremely high, but still the sphere 
> still appears smooth:
> http://www.vtk.org/Wiki/VTK/Examples/Visualization/QuadricLODActor
>
> Arnaud, even before we try to change the number of divisions - can you 
> see a difference (smooth sphere vs not smooth sphere) when you vary 
> the frame rate from say 15 to 1e20 ?
>
> Thanks,
>
> David

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