Variable lvr2::shared_vertex_table

Variable Documentation

static const int lvr2::shared_vertex_table[8][28] = {{-1, 0, 0, 1, -1, -1, 0, 2, 0, -1, 0, 3, -1, 0, -1, 5, -1, -1, -1, 6, 0, -1, -1, 7, 0, 0, -1, 4}, {1, 0, 0, 0, 1, -1, 0, 3, 0, -1, 0, 2, 0, 0, -1, 5, 1, 0, -1, 4, 1, -1, -1, 7, 0, -1, -1, 6}, {1, 1, 0, 0, 0, 1, 0, 1, 1, 0, 0, 3, 1, 1, -1, 4, 0, 1, -1, 5, 0, 0, -1, 6, 1, 0, -1, 7}, {0, 1, 0, 0, -1, 1, 0, 1, -1, 0, 0, 2, 0, 1, -1, 4, -1, 1, -1, 5, -1, 0, -1, 6, 0, 0, -1, 7}, {0, 0, 1, 0, -1, 0, 1, 1, -1, -1, 1, 2, 0, -1, 1, 3, -1, 0, 0, 5, -1, -1, 0, 6, 0, -1, 0, 7}, {1, 0, 1, 0, 0, 0, 1, 1, 0, -1, 1, 2, 1, -1, 1, 3, 1, 0, 0, 4, 0, -1, 0, 6, 1, -1, 0, 7}, {1, 1, 1, 0, 0, 1, 1, 1, 0, 0, 1, 2, 1, 0, 1, 3, 1, 1, 0, 4, 0, 1, 0, 5, 1, 0, 0, 7}, {0, 1, 1, 0, -1, 1, 1, 1, -1, 0, 1, 2, 0, 0, 1, 3, 0, 1, 0, 4, -1, 1, 0, 5, -1, 0, 0, 6}}

A table coding the relations between shared vertices of adjacent positions in the grid created during the marching cubes reconstruction process.

Each box corner in the grid is shared with 7 other boxes. To find an already existing corner, these boxes have to be checked. The following table holds the information where to look for a given corner. The coding is as follows:

Table row = query vertex

Each row consists of 7 quadruples. The first three numbers indicate, how the indices in x- y- and z-direction have to be modified. The fourth entry is the vertex of the box correspondig to the modified indices.

Example: index_x = 10, index_y = 7, index_z = 5

Query vertex = 5

First quadruple: {+1, 0, +1, 0} Indices pointing to the nb-box: 10 + 1, 7 + 0, 5 + 1. –> The first shared vertex is vertex number 0 of the box in position (11, 7, 6) of the grid.

Simple isn’t it?