anchor.diff:                                  end-arrow
                                   start-arrow
                                   (width .01)
  -                                (end-arrow-start-width (* 2 width))
  +                                (arrow-width (* 2 width))
  +                                (arrow-length width)
  +                                (end-arrow-start-width arrow-width)
                                   (end-arrow-end-width 0d0)
  -                                (end-arrow-length width)
  -                                (start-arrow-start-width (* 2 width))
  +                                (end-arrow-length arrow-length)
  +                                (start-arrow-start-width arrow-width)
                                   (start-arrow-end-width 0d0)
  -                                (start-arrow-length width)
  +                                (start-arrow-length arrow-length)
                                   (offset '(0 0 .33))
                                   configuration-map)
     "Draw arrow orthogonal to OFFSET"
     (let* ((v (tf-translation (scene-graph-tf-relative scene-graph tail tip
                                                        :configuration-map configuration-map)))
            (y (amino::tf-orth v offset)))
  -    (item-arrow-axis tail name
  -                     :options options
  -                     :translation offset
  -                     :axis (vec3-normalize y)
  -                     :length (vec-norm y)
  -                     :width width
  -                     :end-arrow end-arrow
  -                     :start-arrow start-arrow
  -                     :end-arrow-start-width end-arrow-start-width
  -                     :end-arrow-end-width end-arrow-end-width
  -                     :end-arrow-length end-arrow-length
  -                     :start-arrow-start-width start-arrow-start-width
  -                     :start-arrow-end-width start-arrow-end-width
  -                     :start-arrow-length start-arrow-length)))
  +    (nconc
  +     (item-arrow-axis tail name
  +                      :options options
  +                      :translation offset
  +                      :axis (vec3-normalize y)
  +                      :length (vec-norm y)
  +                      :width width
  +                      :end-arrow end-arrow
  +                      :start-arrow start-arrow
  +                      :end-arrow-start-width end-arrow-start-width
  +                      :end-arrow-end-width end-arrow-end-width
  +                      :end-arrow-length end-arrow-length
  +                      :start-arrow-start-width start-arrow-start-width
  +                      :start-arrow-end-width start-arrow-end-width
  +                      :start-arrow-length start-arrow-length))))
   
   
   (defun draw-dimension-angular (scene-graph parent name
  
positive.code:                                  offset
                                   angle
                                   end-arrow
                                   (end-arrow-start-width (* 2 width))
                                   (end-arrow-end-width 0d0)
                                   (end-arrow-length width)
                                   start-arrow
                                   (start-arrow-start-width (* 2 width))
                                   (start-arrow-end-width 0d0)
                                   (start-arrow-length width)
                                   )
    (declare (ignore scene-graph))
    (let* ((start-angle (if start-arrow
  
negative.code:      (when start-arrow
         (list (item-cone-axis (draw-subframe name "body") (draw-subframe name "start-arrow")
                               :options options
                               :height start-arrow-length
                               :start-radius (/ start-arrow-start-width 2)
                               :end-radius 0
                               :axis (vec3* 0 -1 0)
                               :translation (vec3* radius 0 0)
                               )))
  