I always thought that these techniques only work because they use multiple viewpoints of the same object (with the same lightning), can infer topography from th

I always thought that these techniques only work because they use multiple viewpoints of the same object (with the same lightning), can infer topography from these and then, knowing that, can "figure out" the lighting. Would be nice to know how well this would work with just very few images, maybe even with different positions, let alone a single image.