libGDX set rotation point 3D

Question

I have two objects base and weapon and I need to set rotate point of weapon to position of base.

public Test(){
position1 = new Vector3(0,0,0);
baseModel = m         


        

Answer 1

A rotation around a point is the same as translating to that point, rotating and then translating back.
So this process consists of 3 steps:

1. Translate to the rotationPoint, for example translate(3, 0, 0)
2. Rotate arround the center (which is now the rotationPoint), for example rotate(0,1,0, 45*delta)
3. Translate back (the translation is relative to the rotation), for example translate(-3, 0, 0);

In this case the code then looks like this:

weapon.transform.translate(3, 0, 0).rotate(0,1,0, 45*delta).translate(-3, 0, 0);