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<p class=MsoNormal>Hi Vtk User,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span lang=EN-GB>I want to slice through a volume about an
arbitrary vector.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>I give 2 points p1 and p2, from which i
calculate the vector as shown below. I want to have the axial from point p1 In the
direction of the vector. <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>I do the following transformations: Translation
to origin, rotation to make vector parallel to z axis, rotate about z axis and
finally translate back to the p1 which leads to a <o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Transformation matrix. Finally i apply the
axial transform matrix to the transformation matrix and get the transformation
for axial view. I set the transform to my imagereslicer and<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Update the imagereslicer and imageviewer.
But I do not get any image as output and i don’t know where is the
mistake ? Can someone help me, I have copied the code below.<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> normal[0] = p2[0]-p1[0];<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> normal[1] =
p2[1]-p1[1];<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> normal[2] =
p2[2]-p1[2];<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> point[0] =
p1[0]; point[1] = p1[1]; point[2] = p1[2];<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'><o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'>//transformation<o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> t_matrix[16] = {1, 0, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
1, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 1, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'>
-point[0], -point[1], -point[2], 1};<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
translation_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> translation_matrix->DeepCopy(t_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'>//rotation to make vector parallel to the z axis<o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> diagonal = sqrt (pow(normal[0],2) +
pow(normal[1],2) + pow(normal[2],2) );<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> intermediate_dia = sqrt ( pow(normal[0],2) +
pow(normal[1],2) );<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> cos_theta = normal[2] / diagonal;<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> sin_theta = intermediate_dia / diagonal;<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> r_matrix[16] = {cos_theta, 0, sin_theta, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
1, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> -sin_theta,
0, cos_theta, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 0, 1};<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
rotation_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> rotation_matrix->DeepCopy(r_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'>//rotation in Z axis by 180 degree<o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> cos_theta_z = cos(3.14159);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> sin_theta_z = sin(3.14159);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> r_matrix_z[16] = { cos_theta_z,
-sin_theta_z, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> sin_theta_z,
cos_theta_z, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 1, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 0, 1};<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
rotation_matrix_z = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> rotation_matrix_z->DeepCopy(r_matrix_z);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'>//translate back to object position<o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> bt_matrix[16] = {1, 0, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
1, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 1, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> point[0],
point[1], point[2], 1};<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
backtranslation_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> backtranslation_matrix->DeepCopy(bt_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:green'>//get the final transformation matrix to apply on the image<o:p></o:p></span></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
intermediate_transformation_1 = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
intermediate_transformation_2 = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
final_transformation_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4::Multiply4x4(translation_matrix,
rotation_matrix, intermediate_transformation_1);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4::Multiply4x4(intermediate_transformation_1,
rotation_matrix_z, intermediate_transformation_2); <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4::Multiply4x4(intermediate_transformation_2,
backtranslation_matrix, final_transformation_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> <span
style='color:blue'>double</span> a_matrix[16] = { 1, 0, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
1, 0, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 1, 0, <o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> 0,
0, 0, 1};<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
axial_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> axial_matrix->DeepCopy(a_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4 *
axial_transformation_matrix = vtkMatrix4x4::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrix4x4::Multiply4x4(final_transformation_matrix,
axial_matrix, axial_transformation_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> vtkMatrixToLinearTransform
* axial_transform = vtkMatrixToLinearTransform ::New();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> axial_transform->SetInput(axial_transformation_matrix);<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> axial_transform->Update();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New";color:green'><o:p> </o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New";color:green'> </span><span
style='font-size:10.0pt;font-family:"Courier New"'>vtkImageReslice*</span><span
style='font-size:10.0pt;font-family:"Courier New"'> <span lang=EN-GB>Imagereslicer
= </span></span><span style='font-size:10.0pt;font-family:"Courier New"'>vtkImageReslice::New();</span><span
lang=EN-GB style='font-size:10.0pt;font-family:"Courier New";color:green'><o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> Imagereslicer->SetResliceTransform(axial_transform);<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:35.4pt;text-indent:35.4pt;text-autospace:
none'><span lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'>Imagereslicer-></span><span
lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'> </span><span
style='font-size:10.0pt;font-family:"Courier New"'>SetResliceAxesOrigin (0, 0,
point[2]); </span><span lang=EN-GB style='font-size:10.0pt;font-family:
"Courier New"'><o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> Imagereslicer->Update();<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:35.4pt;text-indent:35.4pt;text-autospace:
none'><span style='font-size:10.0pt;font-family:"Courier New"'>vtkImageViewer2
* Imageviewer = vtkImageViewer2::New();<o:p></o:p></span></p>
<p class=MsoNormal style='margin-left:35.4pt;text-indent:35.4pt;text-autospace:
none'><span style='font-size:10.0pt;font-family:"Courier New"'>Imageviewer ->SetInput(</span><span
lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'>Imagereslicer</span><span
style='font-size:10.0pt;font-family:"Courier New"'>->GetOutput() );</span><span
lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'><o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> Imageviewer->UpdateDisplayExtent();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> Imageviewer()->Render();<o:p></o:p></span></p>
<p class=MsoNormal style='text-autospace:none'><span lang=EN-GB
style='font-size:10.0pt;font-family:"Courier New"'> Imageviewer->Update();<o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB style='font-size:10.0pt;font-family:"Courier New"'> </span><span
lang=EN-GB><o:p></o:p></span></p>
<p class=MsoNormal><span lang=EN-GB>Regards, <o:p></o:p></span></p>
<p class=MsoNormal>Kana Arunachalam Kannappan<o:p></o:p></p>
<p class=MsoNormal>Research Associate<o:p></o:p></p>
<p class=MsoNormal>FH OÖ Forschungs & Entwicklungs GmbH<o:p></o:p></p>
<p class=MsoNormal>Stelzhamer Strasse 23,<o:p></o:p></p>
<p class=MsoNormal>4600 Wels,<o:p></o:p></p>
<p class=MsoNormal>Austria.<o:p></o:p></p>
<p class=MsoNormal>Phone: +43 (0)7242 72811 -4420<o:p></o:p></p>
<p class=MsoNormal>kana.arunachalam@fh-wels.at<o:p></o:p></p>
<p class=MsoNormal>www.fh-ooe.at; www.3dct.at<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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