DFBI Rotation and Translation Motion

jfn · March 20, 2022, 10:55

Hi,

I am defining "DFBI rotation and translation" motion for a 6DOF body and assign it to the corresponding region as motion specification. However I am not sure the order of rotations (axis) for this motion. (For example, is it x-y-z, z-x-y or roll-pitch-yaw in terms of Euler convention) I couldn't find the information in the user guide. Is there anyone who can help me with it?

Thanks

DRiver · March 21, 2022, 09:35

Hi Jfn,

The rotation axes are only associated with the laboratory coordinate system. The rotation around the X-axis of the lab coordinate system is called "X-rotation" and so on. There's not something like a convention, it only depends on the orientation your body has in the mesh.

jfn · March 21, 2022, 12:33

I understand that but there should be an order of those rotation axes. 6dof solver updates (next) body position and orientation with respect to a predefined order. We know that final orientation of a body after let’s say successive rotation of 30deg-13deg-67deg about x-y-z is not same with z-x-y order. I am wondering that what is the predefined order for DFBI rotation and translation motion?

March 20, 2022, 10:55	DFBI Rotation and Translation Motion	#1
jfn New Member Join Date: Mar 2018 Posts: 5 Rep Power: 8	Hi, I am defining "DFBI rotation and translation" motion for a 6DOF body and assign it to the corresponding region as motion specification. However I am not sure the order of rotations (axis) for this motion. (For example, is it x-y-z, z-x-y or roll-pitch-yaw in terms of Euler convention) I couldn't find the information in the user guide. Is there anyone who can help me with it? Thanks

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March 21, 2022, 09:35		#2
DRiver New Member Daniel Riveros Join Date: Nov 2015 Location: Genoa, Italy Posts: 14 Rep Power: 10	Hi Jfn, The rotation axes are only associated with the laboratory coordinate system. The rotation around the X-axis of the lab coordinate system is called "X-rotation" and so on. There's not something like a convention, it only depends on the orientation your body has in the mesh.

March 21, 2022, 12:33		#3
jfn New Member Join Date: Mar 2018 Posts: 5 Rep Power: 8	I understand that but there should be an order of those rotation axes. 6dof solver updates (next) body position and orientation with respect to a predefined order. We know that final orientation of a body after let’s say successive rotation of 30deg-13deg-67deg about x-y-z is not same with z-x-y order. I am wondering that what is the predefined order for DFBI rotation and translation motion?