Slide 40: Silhouette consistency - Why do we want to keep this and how? I understand the importance of color and smoothness consistency but not silhouette. I also get that for each angle, there is one point at the tangent where the surface meets the line of sight and the surface normal is perpendicular, but how do you match this with the other views?
The point is simply to use the extra information that at silhouettes borders, "there is one point where the surface meets the line of sight and the surface normal is perpendicular". This is provides more constraints on the 3D shape than just taking the intersection of silhouettes. It helps recover a more accurate and regular surface.
