Relative keyframe in 3D

sometimes when annotating 3d boxes docid\ jw2jfj5i04upvcc7hv3ek , you need to annotate a box that has a fixed location with respect to another 3d box, such as a rider on a bike or a car on a trailer to make this easier, you can use the 'relative keyframe' feature drawing process find the 'best frame' for the two objects right click on the current object select the relative keyframe in the context menu select the other object that you wish to place the current object relative to the current object will be placed as it is to the selected object in the current frame in all keyframes