for (int i = 0; i < RenderConstants.SPP_PASS; ++i) {
double oy = random.nextDouble();
double ox = random.nextDouble();
cam.calcViewRay(ray, random, (-halfWidth + (x + ox)
/ height), (-.5 + (y + oy) / height));
scene.pathTrace(state);
sr += ray.color.x;