TailorNet garment model assumes that the garment template is a submesh of SMPL body template, thereby it can take skinning weights from SMPL model. But that doesn't hold up for garments like skirt. First, we tried attaching a skirt template to the root joint of SMPL where the skirt is only subjected to the global rotation of SMPL pose. All other deformations are learned as displacements in a reasonable manner as shown in our paper. However, this design doesn't use the articulation of underlined body parts like legs and hence it is limiting.
Hence, we propose a simple modification to our garment model which works well for skirt. We drape a simple skirt template on canonical body and calculate skinning weights of each skirt vertex as a weighted sum of SMPL skinning weights of K=100 nearest body vertices where weights of sum are inversely proportional to distances. This creates a primitive smooth skirt base which is articulated by SMPL pose and shape, and over which the displacements can be added to predict realistic skirt. Associating each skirt vertex with K=100 nearest body vertices instead of just one, reduces the sudden discontinuity of association between two legs.