def score(guess, e, v, per_pixel=False):
"""calculates cost function of given surface
guess - surface to measure
e - image of original surface
v - light vector used to iluminate original surface
per_pixel - if True, cost value is divided by number comparision points
"""
e_guess = surface2im(guess, v)
cost = (e_guess - e)**2
if per_pixel:
cost = torch.average(cost)
return torch.sum(cost)
def average(*args, **kwargs):
return torch.average(*args, **kwargs)