- empty_values { front = value_at values (i-1) j k,
- back = value_at values (i+1) j k,
- left = value_at values i (j-1) k,
- right = value_at values i (j+1) k,
- down = value_at values i j (k-1),
- top = value_at values i j (k+1),
- front_left = value_at values (i-1) (j-1) k,
- front_right = value_at values (i-1) (j+1) k,
- front_down =value_at values (i-1) j (k-1),
- front_top = value_at values (i-1) j (k+1),
- back_left = value_at values (i+1) (j-1) k,
- back_right = value_at values (i+1) (j+1) k,
- back_down = value_at values (i+1) j (k-1),
- back_top = value_at values (i+1) j (k+1),
- left_down = value_at values i (j-1) (k-1),
- left_top = value_at values i (j-1) (k+1),
- right_down = value_at values i (j+1) (k-1),
- right_top = value_at values i (j+1) (k+1),
- front_left_down = value_at values (i-1) (j-1) (k-1),
- front_left_top = value_at values (i-1) (j-1) (k+1),
- front_right_down = value_at values (i-1) (j+1) (k-1),
- front_right_top = value_at values (i-1) (j+1) (k+1),
- back_left_down = value_at values (i+1) (j-1) (k-1),
- back_left_top = value_at values (i+1) (j-1) (k+1),
- back_right_down = value_at values (i+1) (j+1) (k-1),
- back_right_top = value_at values (i+1) (j+1) (k+1),
+ empty_values { front = value_at values (i - 1) j k,
+ back = value_at values (i + 1) j k,
+ left = value_at values i (j - 1) k,
+ right = value_at values i (j + 1) k,
+ down = value_at values i j (k - 1),
+ top = value_at values i j (k + 1),
+ front_left = value_at values (i - 1) (j - 1) k,
+ front_right = value_at values (i - 1) (j + 1) k,
+ front_down =value_at values (i - 1) j (k - 1),
+ front_top = value_at values (i - 1) j (k + 1),
+ back_left = value_at values (i + 1) (j - 1) k,
+ back_right = value_at values (i + 1) (j + 1) k,
+ back_down = value_at values (i + 1) j (k - 1),
+ back_top = value_at values (i + 1) j (k + 1),
+ left_down = value_at values i (j - 1) (k - 1),
+ left_top = value_at values i (j - 1) (k + 1),
+ right_down = value_at values i (j + 1) (k - 1),
+ right_top = value_at values i (j + 1) (k + 1),
+ front_left_down = value_at values (i - 1) (j - 1) (k - 1),
+ front_left_top = value_at values (i - 1) (j - 1) (k + 1),
+ front_right_down = value_at values (i - 1) (j + 1) (k - 1),
+ front_right_top = value_at values (i - 1) (j + 1) (k + 1),
+ back_left_down = value_at values (i + 1) (j - 1) (k - 1),
+ back_left_top = value_at values (i + 1) (j - 1) (k + 1),
+ back_right_down = value_at values (i + 1) (j + 1) (k - 1),
+ back_right_top = value_at values (i + 1) (j + 1) (k + 1),