The VectorForce constraint applies constant linear force on an assembly. The direction and strength of the force is determined by a Vector3 and can be relative to an attachment on the part, another attachment, or the world coordinate system.

Force Location

By default, force is applied to the assembly at the location of Attachment0. Thus, if its center of mass is not aligned with the direction/point of force, torque will be applied as well. If desired, force can be focused at the center of mass by toggling on ApplyAtCenterOfMass.

ApplyAtCenterOfMass = false
ApplyAtCenterOfMass = true


By default, force is applied relative to Attachment0. If the parent assembly rotates, the force will change direction to match the adjusted orientation of the attachment; visualize this behavior in how the thruster of a rocket pushes it forward, regardless of the rocket's rotation.

If RelativeTo is set to World, force will be applied in world coordinates, independent of the parent or attachment orientations; visualize this behavior as a directional force like the wind blowing against an object.

If RelativeTo is set to Attachment1, force will be applied relative to Attachment1 and, if the attachment rotates, the force will change to match its orientation.

RelativeTo = Attachment0
RelativeTo = World