What is glacial-valley?

Glacial Valley is a browser-based 3D scene of an alpine mountain valley at sunrise that you can walk around in real time. There are no image textures, no 3D model files, and no game engine involved. Every visual element, the mountains, the river, the 85,000 individual grass blades, the birds circling overhead, the fish rings on calm water, is calculated from scratch using mathematics each time the page loads. The whole scene is ready to explore in about 3 to 5 seconds. The project is written in roughly 2,400 lines of JavaScript using a library called Three.js, which handles rendering 3D graphics in the browser. You can move around with the WASD keys, look around by holding the mouse cursor at the edge of the screen, sprint with Shift, jump with Space, and wade into the river. The water appears with a blue-green color from simulated glacial sediment scattering, and the river bed becomes visible in shallow areas. The README explains some of the techniques used. The terrain shape comes from a layered noise function that also drives where the river runs, where boulders sit, and where grass grows. Shadow calculations are baked once at load time: the sun position is fixed, so the code traces rays across the terrain to figure out which areas are in shade and colors them with cooler blue tones accordingly. Water is rendered with two passes that simulate how light bends and how color fades with depth. Grass blades individually respond to a simulated wind gust effect. All the visual output goes through a post-processing step that applies a film-style tone curve, slight grain, a gentle edge darkening, and an exposure adjustment that responds to whether you are looking toward the sun. The result is a scene that looks photorealistic despite being entirely mathematical. To run it locally you need any static file server and a browser that supports WebGL2. The repository includes a small Python script that starts a local server on port 8123.