Autodesk Forge View Cube

Your code is changing the camera's position... Are you trying to change the position of the model or that of the camera? ...

To change the position of the camera try navigation.setView:

const position = new THREE.vector3(x,y,z)
const target = NOP_VIEWER.navigation.getTarget()
viewer.nativation.setView(position, target)

EDIT

To translate (move) the entire model try translate all the fragments:

const total = NOP_VIEWER.model.getInstanceTree().fragList.length //fragment is 0 indexed and increments by 1 so basically iterate from 0 to length -1 

//...
for (int i=0,i<total,i++){
const fragProxy = NOP_VIEWER.impl.getFragmentProxy(NOP_VIEWER.model,i);

                const position = new THREE.Vector3(
                    target.x - fragProxy.offset.x,
                    target.y - fragProxy.offset.y,
                    target.z - fragProxy.offset.z);

                fragProxy.position = position;

                fragProxy.updateAnimTransform();

}
            viewer.impl.sceneUpdated(true);

See this sample here for more details.