Best way to display offset position in direct manipulation design software?

I'm thinking on how to solve for an application that uses real-time positioning to project images.

It uses a beacon (same as motion capture) that is hidden and sewed into a person clothes

When the beacon is detected, a projector will point an image to a default spot which is the supposed to be a midpoint between these two LEDs.

I need to design a visual representation of the screen but with a way to allow direct manipulation of an offset position, in this case, to drag it down from that middle point to the desired offset location. I do have another panel for precise movement (X Y Z coordinates) but I would like the user to do it with direct manipulation easily. Is the representation I created well for this?

Are there other examples/innovation in those types of graphical software manipulation?. I have been trying to read and find HCI journals to read about design patterns in design software but could not find many.

Ideally, the solution can be applied for mouse + keyboard or touchscreen inputs