The TIN data structure is based on two basic elements: points with x,y,z values, and a series of edges joining these points to form triangles. This triangular mosaic forms a continuous faceted surface, much like a jewel. TIN's triangulation method satisfies the Delaunay criterion.
Format
TIN /* File type identifier */ BEGT /* Beginning of TIN group */ TNAM name /* Name of TIN */ MAT id /* TIN material id */ VERT nv /* Beg. of vertices */ x1 y1 z1 lf1 /* Vertex coords. */ x2 y2 z2 lf2 . . . xnv ynv znv lfnv TRI nt /* Beg. of triangles */ v11 v12 v13 /* Triangle vertices */ v21 v22 v23 . . . vnt1 vnt2 vnt3 ENDT /* End of TIN group */ /* Repeat TIN group for other TINs */Cards
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Card Type |
TIN |
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Description |
File type identifier. Must be on first line of file. No fields. |
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Required |
YES |
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Card Type |
BEGT |
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Description |
Marks the beginning of a group of cards describing a TIN. There should be a corresponding ENDT card at a latter point in the file. No fields. |
|
Required |
YES |
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Card Type |
TNAM |
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Description |
Provides a name to be associated with the TIN. |
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Required |
NO |
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Format |
TNAM name |
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Sample |
TNAM bathymetry |
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Field |
Variable |
Value |
Description |
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1 |
name |
str |
The name of the TIN. |
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Card Type |
MAT |
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Description |
Associates a material id with the TIN. This is typically the id of the material which is below the TIN. |
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Required |
NO |
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Format |
MAT id |
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Sample |
MAT 3 |
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Field |
Variable |
Value |
Description |
|
1 |
id |
+ |
The material ID. |
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Card Type |
VERT |
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|
Description |
Lists the vertices in the TIN |
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|
Required |
YES |
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Format |
VERT nv |
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Sample |
VERT 4 |
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|
Field |
Variable |
Value |
Description |
|
1 |
nv |
+ |
The number of vertices in the TIN. |
|
2-4 |
x,y,z |
± |
Coordsinates of vertex. |
|
5 |
lf |
0,1 |
Locked / unlocked flag for vertex (optional). 0=unlocked, 1=locked. Repeat fields 2-5 nv times. |
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Card Type |
TRI |
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|
Description |
Lists the triangles in the TIN |
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|
Required |
NO |
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|
Format |
TRI nt |
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|
Sample |
TRI 4 |
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Field |
Variable |
Value |
Description |
|
1 |
nt |
+ |
The number of triangles in the TIN. |
|
2-4 |
v1,v2,v3 |
+ |
Vertices of triangle listed in a counter-clockwise order. Repeat nt times. |
|
Card Type |
ENDT |
|
Description |
Marks the end of a group of cards describing a TIN. There should be a corresponding BEGT card at a previous point in the file. No fields. |
|
Required |
YES |