Rotating two separate objects within same rotation point

Unity Engine
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1

Hi guys, I have one question about rotating two separating objects within same rotation point.
I have two separate gameobjects and both of them have a child object inside(one is for body and one is for accessory like cap etc, and I am doing something like sprite billboarding).
When I rotate two of the objects together, they rotate at different rotation point. How do I make them rotate at the same point without combining those two gameobjects inside a same parent object. Is there any math I need to use to calculate the rotation point?

2

You could temporarily parent the objects to an invisible object at the center of rotation, then rotate the invisible object, then unparent the objects.

1 Like
3

Hi, thank you for your reply. It looks like a good solution but sorry for me being a little bit stubborn here, is there anyway to do this without create another invisible parent object? I have these two objects pack inside different parents. I will probably consider the structure again if its not viable.

4

Yes. The steps to the math are basically:

  • subtract the offset
  • rotate the position (quaternion multiply)
  • add the offset back in
  • rotate the object’s orientation
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5

Hi, thank you for the explanation. I ended up using the first method and it works fine!