Create a detailed 3D animation of a boy sitting on a brown horse

Create a detailed 3D animation of a boy sitting on a brown horse. The boy should be dressed in casual clothes and appear relaxed and happy.. The horse is robust and healthy looking., with a shiny coat. The scene should be set in an open field with green grass and mountains in the background., under a blue sky with few clouds. The animation should capture the natural movement of the horse and the boy., with the horse walking at a gentle pace and the boy moving slightly, as if he was enjoying the ride.