Advanced AI Prompt for Procedural Terrain Flyover Shaders

Act as a Technical Environment Artist. Write a highly complex vertex shader that physically displaces a massive, flat 3D grid geometry along the Y-axis to dynamically generate an infinite, procedural mountain landscape. The elevation data must be driven entirely by mathematical Fractional Brownian Motion (fBm) utilizing 5 octaves of Perlin noise, multiplied by the [ELEVATION_SCALE] parameter. Within the corresponding fragment shader, programmatically map a [TEXTURE_TYPE] (e.g., wireframe grid, low-poly flat shading, or realistic rock/snow) conditionally based on the computed vertex altitude and slope angle. Inject an exponential squared (`exp2`) distance fog utilizing [FOG_DENSITY] to obscure the horizon line, and continuously offset the noise coordinates via the `uTime` uniform to simulate a low-altitude, high-speed camera flyover at [FLIGHT_SPEED].