They are, the output you're so disdainful of reflects methods even more complex than you're imagining. It's a tough problem. The best work I've seen recently (

They are, the output you're so disdainful of reflects methods even more complex than you're imagining. It's a tough problem. The best work I've seen recently (from MIT) uses two sensors with different polarization filters to get an additional signal to help with noise rejection and surface estimation.