三列火车共用轨道且零碰撞的信号铁路模拟

Build a self-running railway simulation in the browser as one self-contained HTML file, using Three.js. Create a small diorama landscape with green terrain, hills, trees, a village, a river and stations, crossed by a shared track layout with several junctions and switches. Run at least three trains on the same layout at once. Divide the track into blocks: a signal clears only when the block ahead is empty, and switches flip automatically so paths never conflict. Trains must never collide and the simulation must loop forever without any user input. Add working signals, a slowly moving camera that follows the trains or flies around the layout, and a small info panel listing each train and its status. Keep a clean low-poly look with soft daylight. Done means a long run with several trains crossing junctions, waiting at red signals and zero collisions.