<div dir="ltr">I forgot one thing, the vtkPoints can not hold a 4-dimension vtkDataArray so I cannot store the control points in the vtkStructuredGrid. Currently I stored it separately in a vtkDataArray for test. Do I need to implement a vtkPoints subclass likt vtkControlPoints to allow it store 4-dimension coordinates? </div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Jun 30, 2015 at 12:42 PM, David Thompson <span dir="ltr"><<a href="mailto:david.thompson@kitware.com" target="_blank">david.thompson@kitware.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi Lin,<br>
<span class=""><br>
> I have finished the conversion from NURBS patch to Bezier patch and generation of surface meshes.<br>
><br>
> Now we can load some real nurbs shapes to test. :-)<br>
<br>
</span>Great! I'm working on 2 sources of data.<br>
<br>
+ [CGM](<a href="https://bitbucket.org/fathomteam/cgm" rel="noreferrer" target="_blank">https://bitbucket.org/fathomteam/cgm</a>) provides a nice interface to OpenCascade's surface definitions, including these methods:<br>
<br>
<a href="https://bitbucket.org/fathomteam/cgm/src/1aab72dc7c4ca6d0333a88df7b857e49d661db43/geom/Surface.hpp?at=master#cl-370" rel="noreferrer" target="_blank">https://bitbucket.org/fathomteam/cgm/src/1aab72dc7c4ca6d0333a88df7b857e49d661db43/geom/Surface.hpp?at=master#cl-370</a><br>
<a href="https://bitbucket.org/fathomteam/cgm/src/1aab72dc7c4ca6d0333a88df7b857e49d661db43/geom/Curve.hpp?at=master#cl-364" rel="noreferrer" target="_blank">https://bitbucket.org/fathomteam/cgm/src/1aab72dc7c4ca6d0333a88df7b857e49d661db43/geom/Curve.hpp?at=master#cl-364</a><br>
<br>
CGM has a few CAD models for testing in the "test" directory of the source repo.<br>
<br>
+ [PetIGA](<a href="https://bitbucket.org/dalcinl/petiga" rel="noreferrer" target="_blank">https://bitbucket.org/dalcinl/petiga</a>) has 3D NURBS including simulation results but is in a binary file format that is undocumented (except in the source).<br>
<span class="HOEnZb"><font color="#888888"><br>
        David</font></span></blockquote></div><br></div>