[Insight-users] calculate normal
rashedk
rashed.vtk at googlemail.com
Thu Feb 21 14:50:51 EST 2008
Hi,
In the documentation of ComputeNormal of SimplexMesh it says:
CovariantVectorType itk::SimplexMesh< TPixelType, VDimension, TMeshTraits
>::ComputeNormal ( unsigned long idx ) const
compute the normal vector in the specified mesh point
I need to pass in the index of the mesh point as a parameter. Which function
returns the index of a mesh point on a simplex mesh??
Thanks,
Rashed
Alex. GOUAILLARD-2 wrote:
>
> Hi rashed,
>
> The meshtraits is a list of type definition to finely tune your structure
> depending on your usage. You can read more in the itk software guide:
> Chapter 4.3.4 "Customizing the Mesh", page 70.
>
> A meshtrait is provided by default, so you can basically ignore that for
> your first experiments and use the itk:SimplexMesh as if it was templated
> only over the PixelType and the Dimension. (Note, the Dimension also has a
> default value, so theoretically, you only need to define a PixelType)
>
>
> //----------------- original code
>
> // NOTE see the default values for Vdimension and TMeshTraits
> template < typename TPixelType,
> unsigned int VDimension = 3,
> typename TMeshTraits = DefaultStaticMeshTraits< TPixelType,
> VDimension,
> VDimension,
> TPixelType,
> TPixelType,
> TPixelType >
> >
> class SimplexMesh : public Mesh<TPixelType, VDimension, TMeshTraits>
>
>
> //-----------------
>
>
> Possible usages:
>
> // simplest
> Typedef itk::SimplexMesh< float > MyFirstSimplexMeshType;
>
> // same thing with second template parameter explicitly set
> Typedef itk::SimplexMesh< float, 3 > MySecondSimplexMeshType;
>
> // full options - stay away from that unless you **really** know what you
> do
> Typedef float PointAndCellDataType;
> typedef float Coord;
> const unsigned int SDimension = 3; // space dimension
> Const unsigned int TDimension = 2; // max topological dim. Surface => 2
>
> typedef itk:: DefaultStaticMeshTraits<
> PointAndCellDataType,
> SDimension,
> TDimension,
> Coord,
> Coord,
> PointAndCellDataType > MeshTraitsType;
>
> typedef SimplexMesh< PointAndCellDataType, SDimension, MeshTraitsType >
> MeshType;
>
>
> On 2/20/08 10:18 AM, "rashedk" <rashed.vtk at googlemail.com> wrote:
>
>>
>> Thanks!
>>
>> What is TMeshTraits in itk::SimplexMesh< TPixelType, VDimension,
>> TMeshTraits
>>> ??
>>
>> What should I pass for TMeshTraits?
>>
>>
>>
>>
>> Leila Baghdadi-2 wrote:
>>>
>>> check InsightApplication/DeformableModel...
>>>
>>> I think that code needs work but I am sure I have the part where it
>>> converts the mesh to pass to vtk.
>>>
>>> HTH
>>>
>>> Leila
>>>
>>> On Wed, 2008-20-02 at 09:21 -0800, rashedk wrote:
>>>>
>>>> Thanks, but now I am stuck trying to display a simplex mesh in VTK. How
>>>> do I
>>>> visualize this mesh? Is there also a way to iterate through every point
>>>> on
>>>> the mesh?
>>>>
>>>> Rashed.
>>>>
>>>>
>>>> Leila Baghdadi-2 wrote:
>>>>>
>>>>> Yep that's right and another note,
>>>>>
>>>>> you "must" create a triangle mesh in order to create a simplex mesh!
>>>>>
>>>>> If you are unsure about how it is done, check the paper
>>>>> simplex mesh
>>>>> by herve delingette of INRIA france
>>>>>
>>>>> good luck
>>>>>
>>>>> Leila
>>>>>
>>>>> On Wed, 2008-20-02 at 12:47 +0100, Iván Macía wrote:
>>>>>> Hi Rashed,
>>>>>>
>>>>>> You can do what you mention with VTK or directly in ITK use
>>>>>> itk::BinaryMask3DMeshSource, which is the equivalent of Marching
>>>>>> Cubes
>>>> in
>>>>>> ITK. As the name implies, you need a binary mask (segmentation) as
>>>> input.
>>>>>>
>>>>>> HTH
>>>>>>
>>>>>> Ivan
>>>>>>
>>>>>> -----Mensaje original-----
>>>>>> De: insight-users-bounces+imacia=vicomtech.org at itk.org
>>>>>> [mailto:insight-users-bounces+imacia=vicomtech.org at itk.org] En nombre
>>>> de
>>>>>> rashedk
>>>>>> Enviado el: miércoles, 20 de febrero de 2008 12:06
>>>>>> Para: insight-users at itk.org
>>>>>> Asunto: Re: [Insight-users] calculate normal
>>>>>>
>>>>>>
>>>>>> Hi,
>>>>>>
>>>>>> How do I convert my 3D image data to a simplex mesh in order to
>>>> compute
>>>>>> the
>>>>>> normals? Checking the class documentation for itk::SimplexMesh
>>>>>> reveals
>>>>>> that
>>>>>> one has to generate a triangle mesh and then use the
>>>>>> itkTriangleMeshToSimplexMeshFilter. But then how do I convert my 3D
>>>> image
>>>>>> data to a triangle mesh?? Do I use vtkContour to produce polyData and
>>>>>> then
>>>>>> convert it to itkMesh using appropriate filters?
>>>>>>
>>>>>> Any help will be appreciated,
>>>>>>
>>>>>> Thanks
>>>>>> Rashed
>>>>>>
>>>>>>
>>>>>>
>>>>>> Luis Ibanez wrote:
>>>>>>>
>>>>>>> Hi Tony,
>>>>>>>
>>>>>>>
>>>>>>> Well.... if you only have a point, then there is no normal to
>>>> compute.
>>>>>>>
>>>>>>> You probably are thinking of a point from a surface, where a point
>>>>>>> belongs to several faces and have other points as neighbors.
>>>>>>>
>>>>>>>
>>>>>>> In that case you may want to look at the itk::SimplexMesh
>>>>>>> http://www.itk.org/Insight/Doxygen/html/classitk_1_1SimplexMesh.html
>>>>>>>
>>>>>>> and its "ComputeNormal" method:
>>>>>>>
>>>>>>
>>>> http://www.itk.org/Insight/Doxygen/html/classitk_1_1SimplexMesh.html#itk_1_1
>>>>>> SimplexMesha5
>>>>>>>
>>>>>>>
>>>>>>> Regards,
>>>>>>>
>>>>>>>
>>>>>>> Luis
>>>>>>>
>>>>>>>
>>>>>>> -------------------
>>>>>>> tony hakki wrote:
>>>>>>>> Is it possible to calculate normal of a point in ITK? If yes, Could
>>>>>> you
>>>>>>>> tell which class should be used?
>>>>>>>> thank you
>>>>>>>>
>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Insight-users mailing list
>>>>>>> Insight-users at itk.org
>>>>>>> http://www.itk.org/mailman/listinfo/insight-users
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> Insight-users mailing list
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>>>>>
>>>>>
>>>>
>>>
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>
>
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