When I lock DoF for Floating Object, it is in global or local coordinate system?

Hello!

Imagine you have a case like this, where red is x-axis, green is y-axis and blue is z-axis:

If I want to lock everything but pitch, I can now use rotationDOF in the floating object definition. For the bottom case where a global coordinate system would align with a local one there would be no issue.

But what about the top case, where the global coordinate system does not align with the local anymore?

I have a feeling that DualSPHysics behind the screen uses a local coordinate system for the floating objects, since I've observed that some angle results come out "wrong" compared with the global coordinate system, but it tilts as I would expect physically - I just need confirmation of this and if possible, how do I specify my own coordinate system for a floating object, to ensure that when using translationDOF and rotationDOF I am locking the degrees of freedom I expect?

Kind regards

Comments

  • Maybe explained in another way, if I rotate my object so it is not aligned in global x y and z, it seems like that I cannot lock local surge, sway, heave, roll, pitch and yaw etc. - and this is what I want to be able to do

    Kind regards

  • You should use in this case POINTLINE of Chrono so you can restrict the directions you want.

    Some examples here: examples\others\ChronoPointline

  • Thanks for pointing me in that direction!

    I found this slide in the documentation:

    Seems like I should be able to do what I want using this and from the videos in the folder you mentioned. I will properly write back next week with how it went :-)

    Kind regards

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