把光源、透镜、棱镜、反射镜、分束器、屏幕——随意摆放——看光按真实的物理规律传播,而不是近轴的近似。每个表面都用斯涅尔定律的矢量形式折射,按菲涅尔系数分配反射强度,并在超过临界角时发生全反射。白光透过玻璃时按真实的 n(λ) 色散。搭一台望远镜、分一束光、把光线困在棱镜里——几何是解析的,物理是诚实的。
A fully-3D geometric-optics bench: place sources, lenses, mirrors, apertures and screens on a calibrated rail, orbit the scene, trace paraxial rays in real time, and read the real image — focal length, magnification, image distance, real/virtual.