Operating system: windows 7 Slicer version: 4.8.1 Expected behavior: Actual behavior: Hello, I create a needle model to insert it to a specific region in my 3D model in slicer. This way, the position of the needle tip and the orientation of the needle is important. The desired pose of the needl…

As I wrote above, there is a mistake in how the B (fromParent_LPS) matrix is constructed in your example above. The correct fromParent_LPS matrix looks something like this: [[ -0.65 -0.44 0.62 -107.59] [ 0.62 0.15 0.76 -227.31] [ -0.43 0.89 0.18 -88.75] [ 0. 0. …

Thanks Mr. Lasso. Actually i saw the topic and i use it for the conversion to have the same rotation matrix in matlab. But i don’t want to use the Matlab bridge extension. I need to know which euler-angles the Slicer rotation matrix is based on?

[image] Mary7291: i don’t want to use the Matlab bridge extension You don’t need to use the entire extension but just use the few lines of code that inverts axes and the matrix. [image] Mary7291: I need to know which euler-angles the Slicer rotation matrix is based on? Euler angles ar…

Thanks, Actually, i’m working on a robotic project and i should define the orientation of my tool. this way i want to know how the transformation module creates the rotation part based on the degrees which can be defined by the users?

Slicer stores transformation as a 4x4 homogeneous transformation matrix , you can use this to compute robot joint coordinates from this matrix ( inverse kinematics ).

Thanks, I think that i misunderstood your previous request. i found that the slicer works on Quaternions based on the Euler angles defined by users. In Matlab, This could be obtained by converting the transformation matrix of slicer to the Quaternion definition and then find the Euler angles of t…

Hello again, I came to the problem again when using the transform module. when i save the transformation matrix even the translation part is changed. why is this happen? is there any way to obtain the same translation part (position) which can be seen in slicer software? Actually i need the posit…

It seems that you don’t put the matrix elements into their correct location because the orientation part is transposed. If the orientation part is incorrect then the translation is computed incorrectly, too. Probably you need to swap the row and column indices. Is the needle model origin at (0,0,0)…

The transposed Matrix was from the inverse in Matlab code. So the arrays are now at the correct locations. [M2] I add a coordinate system to the of the needle by applying the same transform to both of the needle and coordinate system model. [S2] But the problem is still exist…Is there any trans…

Thanks a lot Mr. Lasso. By following your suggestion, now it is work…

Rotation matrix from the Transform Module

Support

lassoan (Andras Lasso) June 10, 2019, 1:25pm 2

See this topic for explanation and solution: Saving Linear Transformation Matrix

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Rotation matrix from the Transform Module

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