Accessible space: For each surface of the object, we assign a corre- sponding accessible space (see Figure 5(b)). We define aik to be the center coordinates of accessible space k of object i. The diagonal of the region is measured by adik, which is used to measure how deep other objects can penetrate into the space during optimization. The size of the accessible space is set from available examples or given as input related to the size of a human body. If the space is very close to the wall in all the examples, the corresponding surface need not be accessible; otherwise, we set it to be the.
