Subdivision wont add any more detail. It will just make the artifacts worse I think.<br><br><div class="gmail_quote">On Thu, Jul 5, 2012 at 7:43 PM, Dale "Luke" Peterson <span dir="ltr"><<a href="mailto:hazelnusse@gmail.com" target="_blank">hazelnusse@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Bill,<br>
Thanks for the reply.<br>
<div class="im"><br>
> VTK does not have an adaptive isosurface algorithm. You can increase the<br>
> dimensions of your sampling and then apply one of several decimation<br>
> algorithms to reduce the polygons. The decimation algorithms will keep more<br>
> polygons in areas with more detail.<br>
<br>
</div>Would it make sense to perhaps use a very course grid on the 3D volume<br>
(vtkSampleFunction), then do subdivision<br>
(vtkButterflySubdivisionFilter) on the output of the contour filter to<br>
increase the number of triangles, and then do decimation to reduce the<br>
number of polygons in areas that don't need it?<br>
<br>
When I start to increase the number of points in vtkSampleFunction,<br>
things get slow because this increases with n^3, but with the<br>
SubDivision approach I think I would be ~n^2 since it would only be<br>
subdividing the surface.<br>
<span class="HOEnZb"><font color="#888888"><br>
~Luke<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
> see for example:<br>
> <a href="http://vtk.org/Wiki/VTK/Examples/Cxx/Meshes/Decimation" target="_blank">http://vtk.org/Wiki/VTK/Examples/Cxx/Meshes/Decimation</a><br>
> and<br>
> <a href="http://vtk.org/Wiki/VTK/Examples/Cxx/Meshes/QuadricDecimation" target="_blank">http://vtk.org/Wiki/VTK/Examples/Cxx/Meshes/QuadricDecimation</a><br>
<br>
<br>
<br>
><br>
><br>
> On Thu, Jul 5, 2012 at 6:51 PM, Dale "Luke" Peterson <<a href="mailto:hazelnusse@gmail.com">hazelnusse@gmail.com</a>><br>
> wrote:<br>
>><br>
>> > If you mean "refine" as smoothing use vtkWindowedSincPolyDataFilter.<br>
>><br>
>> I guess I would like more points to be added in areas where the<br>
>> curvature is high so that the surface is more accurately represented.<br>
>> Does the Sinc filter do that? If not, is there something like [0] or<br>
>> [1] in VTK?<br>
>><br>
>> Luke<br>
>><br>
>> [0] -- Isosurface Computation Made Simple: Hardware Acceleration,<br>
>> Adaptive Refinement and Tetrahedral Stripping, Pascucci, V.<br>
>> [1] -- Time critical isosurface refinement and smoothing, Pascuci, V.,<br>
>> Bajaj, C. doi://10.1145/353888.353894<br>
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><br>
><br>
><br>
><br>
> --<br>
> Unpaid intern in BillsBasement at noware dot com<br>
><br>
<br>
<br>
<br>
</div></div><div class="HOEnZb"><div class="h5">--<br>
“People call me a perfectionist, but I'm not. I'm a rightist. I do<br>
something until it's right, and then I move on to the next thing.”<br>
― James Cameron<br>
</div></div></blockquote></div><br><br clear="all"><br>-- <br>Unpaid intern in BillsBasement at noware dot com<br><br>