[vtkusers] Align vtk cylinder source to a given vector

[Bill Lorensen]

The scale should be:

  transform->Scale(length, 1.0, 1.0);

On Tue, Dec 13, 2016 at 10:48 AM, Bill Lorensen <bill.lorensen at gmail.com>
wrote:

> The arrow source is originally aligned with the x-axis, The cylinder
> source is aligned with the y-axis. Also the cylinder origin is different.
> Replace the transform with
>
>  vtkSmartPointer<vtkTransform> transform =
>     vtkSmartPointer<vtkTransform>::New();
>   transform->Translate(startPoint);
>   transform->Concatenate(matrix);
>   transform->Scale(length, length, length);
>   transform->RotateZ(-90.0); // orient along x axis
>   transform->Translate(0, .5, 0); // translate to end of cylinder
>
>
> On Tue, Dec 13, 2016 at 10:15 AM, M. Jordan <mjordan at live.at> wrote:
>
>> Thank you very much!
>> The example works fine, but when I change the source from arrow to
>> cylinder the result is strange (not aligned).
>> I don't know why
>>
>> ------------------------------
>> *Von:* Bill Lorensen <bill.lorensen at gmail.com>
>> *Gesendet:* Dienstag, 13. Dezember 2016 15:23
>> *An:* Cory Quammen
>> *Cc:* VTK Users; M. Jordan
>> *Betreff:* Re: [vtkusers] Align vtk cylinder source to a given vector
>>
>> This example may help
>> http://www.vtk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/OrientedArrow
>> VTK/Examples/Cxx/GeometricObjects/OrientedArrow ...
>> <http://www.vtk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/OrientedArrow>
>> www.vtk.org
>> Download and Build OrientedArrow. Click here to download OrientedArrow.
>> and its CMakeLists.txt file. Once the tarball OrientedArrow.tar has been
>> downloaded and extracted,
>>
>>
>> On Dec 13, 2016 9:13 AM, "Cory Quammen" <cory.quammen at kitware.com> wrote:
>>
>>> Here's a sketch of how to do this in VTK:
>>>
>>> * Find the cross product h between the normalized default cylinder
>>> axis c and your normalized direction vector v.
>>> * Now compute theta = acos(d) where d is the dot product of c and v.
>>> theta is the rotation angle about h you need to rotate the cylinder to
>>> the direction vector.
>>> * Use vtkTransformFilter with the transform set to a vtkTransform
>>> where you have called vtkTransform::RotateWXYZ (double angle, double
>>> x, double y, double z). theta is in radians, but angle is expected to
>>> be in degrees, so you'll need to convert.
>>>
>>> Hope that helps,
>>> Cory
>>>
>>> On Tue, Dec 13, 2016 at 6:33 AM, M. Jordan <mjordan at live.at> wrote:
>>> > Hi,
>>> >
>>> > i have a cylinder and a given direction vector. Now I want to align the
>>> > cylinder along that vector.
>>> > How can I do this?
>>> >
>>> > Thank you!
>>> >
>>> >
>>> > _______________________________________________
>>> > Powered by www.kitware.com
>>> >
>>> > Visit other Kitware open-source projects at
>>> > http://www.kitware.com/opensource/opensource.html
>>> >
>>> > Please keep messages on-topic and check the VTK FAQ at:
>>> > http://www.vtk.org/Wiki/VTK_FAQ
>>> >
>>> > Search the list archives at: http://markmail.org/search/?q=vtkusers
>>> >
>>> > Follow this link to subscribe/unsubscribe:
>>> > http://public.kitware.com/mailman/listinfo/vtkusers
>>> >
>>>
>>>
>>>
>>> --
>>> Cory Quammen
>>> Staff R&D Engineer
>>> Kitware, Inc.
>>> _______________________________________________
>>> Powered by www.kitware.com
>>>
>>> Visit other Kitware open-source projects at
>>> http://www.kitware.com/opensource/opensource.html
>>>
>>> Please keep messages on-topic and check the VTK FAQ at:
>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>
>>> Search the list archives at: http://markmail.org/search/?q=vtkusers
>>>
>>> Follow this link to subscribe/unsubscribe:
>>> http://public.kitware.com/mailman/listinfo/vtkusers
>>>
>>
>
>
> --
> Unpaid intern in BillsBasement at noware dot com
>



-- 
Unpaid intern in BillsBasement at noware dot com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20161213/0def1073/attachment-0001.html>