cSpace eater









Solving the New Motion

Preliminary Steps

Before having the solver retarget the motion, a few things must first be set up to ensure better results. First, a we run a Python script that allows the footplant constraints to slide on all axis except Y (the vertical axis). This allows the solver to move the footplants so the new model can reach them. Without this step the solver will be forced to keep the footstep in place and make the new model stretch to reach them. Since we generally retargetted to smaller model this step was very important to keep the motions looking natural.

The final step is to add secondary constraints to clean up the motion. In the picture to the right the red lines on the model's arms signify constraints that keep two joints a certain distance apart during a specified time. This process is detailed below.

Tweaking the Motion

Once the motion is solved and looks believable, we then go back and clean up the secondary effects by adding special constraints where needed. For example, since the ant model we used has a larger head than a human, the arm were penetrating the head during some frames of our dancing animation. To fix this problem we simple added another contraint that forced the upper arm joints to stay a fixed distace away from the head for the whole animation. Below are two shots from the same frame of animation. The picture on the right is from the animation before the extra constraint was added and the one on the left is from after.