Element's rotation from XYZ axes?

[2kristof2]

Hello,

I would like to know how to get rotation of an element (rx,ry,rz) if I have its x,y,z axes and their positions (P1, P2, P3 and element's position are given like in the picture below). Some maths are needed but unfortunately calculating angles is not my strong side. Thanks in advance.

 

[IIYAMA]

What has position in your case to do with rotation? If you have 2 positions, then it would be something else.

 

getElementRotation

 

[2kristof2]

The element is attached and getElementRotation won't return actual rotation but rotation before attaching. And yes I know all those functions related to attachments but there are needed even more complicated maths to rotate an element by setting its offsets.

[IIYAMA]

Yea, thought you missed something in your explanation.

You can try to check with getElementMatrix. But I can't help you getting rotations from rotation offsets of matrices, too much for me.

 

 

 

[2kristof2]

3 hours ago, IIYAMA said:

I tried with getElementMatrix but it seems like it doesn't return correct rotations, at least not everytime (there is an option to get rotation from matrix using OOP, this is what I used)

 

 

 

[szekelymilan]

element1
element2 -> attached to element1

When you attach these two, get the rotation of element1, and element2. Save them in a table (rotations).
Then, when you are trying to get the element2's actual rotation, just get the rotation of element1, and have 3 new variables:
differenceX = rotations['element1'][1] - getElementRotation(element1)[1] -- make differenceY and differenceZ like this
Then, you can get the element2's rotation, with rotations['element2'][1] + differenceX, or if it's not working, use - of + instead.

I hope this can be working!

Edited November 30, 2017 by MakroBox