Figure 5:

Geometric constraints in graph construction. (a) Inter-column and intra-column arcs link graph nodes from columns built along the column direction through the pre-segmented surface mesh $S_1$. Each mesh vertex is associated with a column of nodes and $p$ and $q$ represent the coordinates of the mesh vertices where columns are built. Columns located in the same triangle polygon are neighboring columns. The inter-column arcs are deployed between neighboring columns to enforce surface smoothness constraints ${\Delta }_s$. (b) Inter-surface arcs model the separation constraint between the two interacting surfaces $S_1$ and $S_2$. The column $Co{l}_{S_1,p}$ from $S_1$ interacts with $Co{l}_{S_2,p}$ from $S_2$ and ${\Delta }_l$ and ${\Delta }_u$ restrict the minimum and maximum distances between the surface-connected nodes of the two columns, respectively. Best viewed in color.