Spine parts-split: illustration choice decides AI results

The write-up frames the split step as a planning step rather than a button press. In the author's tests, the robot mascot's plan came back with a forearm frame that missed most of the hand, and a head frame considerably wider than the head, so those frames were corrected in chat before splitting, which the author notes is far cheaper than redoing the split.

The body also treats hidden areas as something the split has to anticipate. Because parts must overlap at joints to avoid gaps when animated, the drawing has to add hidden portions such as the shoulder under a shoulder pad, the leg root beneath the torso, or the neck under a helmet ring. That makes it important to state where the joints are in the request, as the author did for the robot by specifying the elbow as a small gold ring under the shoulder pad and the large gold cuff as the wrist on the forearm side.

Drawing order is another point the body ties to the split plan. Limbs drawn behind the torso hide the boundary between limb and body, while the reverse reveals the cut at the root when the arm is raised, and the same holds for the elbow when the forearm is drawn in front of the upper arm. The author notes that joint placement — not visible parts such as a shoulder pad — should be decided with the plan in mind, since placing the shoulder joint at the pad's center made the pad swing outward and open a gap below, and moving the joint inside the torso outline solved it.