Set child position to the parent center of mass?

[TimmyToolman]

I have a rocket ship mesh and I want to attach a PhysicsThrusterComponent to the exact center of mass. I’ve tried a couple of approaches with mixed results

1. In the Components section of the blueprint editor I can see the green sphere that represents the center of mass of the mesh. I can use this to approximately place the thruster in the correct position, but there is room for error.
2. There is a GetCenterOfMass blueprint function, but that gives me (0,0,0). This is presumably local coordinates, relative to the center of the mesh itself, not a value that could be used to set an exact position for a child object.

I’m currently using method (1) which mostly works, but it’s not super accurate. Any slight offset will inherently cause the rocket to veer.

Is there some way I can snap the thruster to the exact center of mass of the rocket mesh? Perhaps I can use the value returned by GetCenterOfMass and convert it to a value that the child object can use, like some kind of LocalToWorld transform?

[Jacky]

You can use Get Center of Mass function in construction script to set the location of the thruster. I had the same issue with thrusters in earlier versions but now it just works since 4.6 with the help of that node. You can see my result here: Physics Thrusters Test with a Colonial Viper - UE4 - YouTube

It has 6 thrusters, one located exactly at the center of mass that makes the ship move forward and backward.

[TimmyToolman]

Thanks again, Jacky. I had actually tried this before, but I must have wired up the construction script wrong because I didn’t work at that time. Second time is the charm! For anyone else who reads this, this is what my working construction script looks like: