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Interpreting the transformation matrix and axis tab

Posted: Thu Jul 20, 2017 7:20 am
by TinaTina
I aligned 2 set points clouds export from AutoCAD (UCS &WCS), they are pair control points.
After I aligned the two clouds by these pair picking pair points, I got a transformation matrix form the properties tab.

0.13709860 0.99055743 0.00005005 -8.10097122
-0.99055731 0.13709860 -0.00047631 31.27651978
-0.00047867 0.00001573 0.99999988 -1.70254374
0.00000000 0.00000000 0.00000000 1.00000000

What does these value mean?
How can I extract Euler angles from transformation matrix? A rotation matrix from Euler angles is formed by combining rotations around the x-, y-, and z-axes. So the cloud compare transformation matrix is in X-,Y-,Z-axes rotation order?
A process by Mike Day: https://d3cw3dd2w32x2b.cloudfront.net/w ... ngles1.pdf
According to this method, I calculated the rotation angles, get the result as attachment:
It's quite different to the second tab result.

Re: Interpreting the transformation matrix and axis tab

Posted: Thu Jul 20, 2017 9:10 am
by daniel
You can copy the transformation (either with CTRL+C directly in the Console, or from the 'Transformation history' section of the cloud properties); then paste it in the 'Edit > Apply Transformation' tool. In this tool you can view the transformation under several modes (matrix, rotation axis and angle + translation, or Euler angles).

Also mind that the rotation axis / angle form is not unique.