浏览器光线追踪

Describe a small scene of analytic primitives (spheres, axis-aligned boxes) in JavaScript and generate a fragment shader that intersects rays with them. Each frame, trace one randomized path per pixel with a few diffuse bounces and a hash-based random seed that changes with the frame number. Blend the new frame into an accumulation texture with weight 1/(frameCount+1) using ping-pong render targets and display the average. Reset frameCount whenever the camera or an object moves so the image re-converges.