LINES GP-WORK TOOL 2224370 - Caterpillar

Vertices Section
The vertices section covers all triangle corner points. The vertices section consists of a contiguous block of vertex records.The order these vertex records appear in the .ttm file determines their vertex number. The first vertex record is assigned a vertex number of 1.The field size of the relative northing and easting is the vertex coordinate size in the header record.The field size of the elevation value is the vertex elevation value size in the header record.Table 2 describes the vertex record.
Table 2
Vertex record    
Field name     Field size (Bytes)     Field type     Meaning    
Relative northing     4 or 8     Float or double     The absolute coordinate less the offset given in the header section.    
Relative easting     4 or 8     Float or double     The absolute coordinate less the offset given in the header section.    
Elevation     4 or 8     Float or double     The absolute grid elevation. The elevation values can be in single or double precision independent of the vertex coordinate size.    Triangles Section
The triangles section lists all of the triangles and their adjacent triangles. The triangles section consists of a contiguous block of triangle records.The order these triangle records appear in the .ttm file determines their triangle number. The first triangle record is assigned a triangle number of 1.The field size of the first, second, and third vertex is the vertex number size in the header record.The field size of the first, second, and third adjacent triangle is the triangle number size in the header record.Table 3 describes the triangle record.
Table 3
Triangles    
Field name     Field size     Field type     Meaning    
First vertex
Second vertex
Third vertex     2 or 4     Short or long integer     A number in the range of 1–# of vertices in the file.    
First adjacent triangle     2 or 4     Short or long integer     A number in the range of 1–# of triangles in the file.
The triangle number of the triangle adjacent to the side of vertex 1 and vertex 2 (1).    
Second adjacent triangle     2 or 4     Short or long integer     A number in the range of 1–# of triangles in the file.
The triangle number of the triangle adjacent to the side of vertex 2 and vertex 3 (1).    
Third adjacent triangle     2 or 4     Short or long integer     A number in the range of 1–# of triangles in the file.
The triangle number of the triangle adjacent to the side of vertex 3 and vertex 1 (1).    
( 1 ) A value of –1 indicates that there is no adjacent triangle.Edge Triangles Section
The edge triangles section lists all the triangles that have less than three adjacent triangles. The edge triangles section consists of a contiguous block of edge triangle records.The field size of the triangle number is the triangle number size in the header record.Table 4 describes the