Three.js 虫子在照片上爬行:逆向运动学腿部与鼠标交互

Build an interactive web demo in Three.js where many small beetles crawl across the surface of a portrait photo. Each beetle has a glossy red body and six thin legs. Legs move in two alternating groups: one group stays planted while the other lifts and steps to a new target, with two-segment inverse kinematics placing each foot. Beetles sample the photo's height or contour so their bodies follow the curved surface and tilt with it. Use a dark green background and a clean card-style interface in a modern typeface. Add a toggle that shows foot landing points, a slider for beetle count and walking speed, a pause button, and a mouse mode switch between wandering, chasing the cursor and fleeing from it. Include short explanatory panels about the gait and leg solving. Deliver it as a static page that can be hosted on GitHub Pages. Done when dozens of beetles walk smoothly without legs jumping.