I don't have any experience with 3D yet, but normally to convert coordinates between two layers you need these two expressions:
Set X to CanvasToLayerX("UI", LayerToCanvasX("Game",Animals.X,Animals.Y), LayerToCanvasY("Game",Animals.X,Animals.Y))
Set Y to CanvasToLayerY("UI", LayerToCanvasX("Game",Animals.X,Animals.Y), LayerToCanvasY("Game",Animals.X,Animals.Y))