Three.js 蒸汽机车驶过稻田，支持多机位切换

Build a browser app in Three.js that shows a detailed black steam locomotive running along a railway through a Japanese countryside. Model the locomotive with a boiler, cab, tender, chimney, and coupled driving wheels with connecting rods that move correctly in sync with speed. Surround the track with terraced green rice paddies divided by narrow paths, irrigation channels, utility poles, scattered trees, a small farmhouse and rolling hills under a pale sky. Lay ballast and rails along a long straight and gentle curve. Add a small control bar at the bottom with speed slider, camera selection (trackside, chase, front, close wheel view) and toggles for scene elements. Animate the train continuously and loop the route. Use realistic matte shading and soft lighting. Deliver a self-contained web project. Done when the wheel and rod motion looks convincing from the close camera and the train runs smoothly through the paddies.