TIN display options control which features of the TIN are displayed. Each display feature associated with TINs is listed in the TIN Display Options dialog accessed by selecting the Display Options command in the Display menu. Most of the items in the dialog represent features of the TIN that can be displayed. The toggle next to the feature can be toggled on or off to control whether or not the feature is displayed. In addition, the window to the left of the check box can be used to set the graphical attributes (line thickness, color, font, etc.) of the feature. The options in the dialog are as follows:
If the Vertices item in the TIN Display Options dialog is set, the TIN vertices are displayed each time the Graphics Window is refreshed. Both a "Locked" and "Unlocked" vertex color may be set so that there is a visible difference when displaying the TIN
If this item is on the lines that make up each triangle are displayed.
3 options are available for the triangle edges:
Auto- draws the material color if faces are not displayed. Uses black or white if the faces are displayed.
Specified- used the color specified next to the triangle edges
Material- displays the material color of the triangle
The Triangle faces item causes the faces of the triangles to be drawn as filled polygons.
The TIN boundary feature is often used in conjunction with contours in order to display the contours without cluttering the screen by displaying each triangle. The first image below shows contours displayed together with the TIN triangles. The second image shows contours displayed with the TIN boundary.
If the Thiessen polygons item is set, a Thiessen polygon for each TIN vertex is displayed each time the display is refreshed. The edges of the Thiessen polygons are formed by the perpendicular bisectors of the edges of the triangles in the TIN. The vertices of these polygons correspond to the centers of the circumcircles of the Delauney triangulation . Any location inside a Thiessen polygon is closer to the TIN vertex contained in that polygon than to any other TIN vertex. The red polygons in the image below correspond to the Thiessen polygons for this TIN.
If the Circumcircles item is set, the circumcircle enclosing the three vertices for each triangle are drawn when the display is refreshed. Circumcircles provide the basis of a Delauney triangulation since the Delauney criterion is satisfied by ensuring that no circumcircle encloses a vertex. Displaying circumcircles can aid in the understanding of the triangulation process. The red circles in the figure are the circumcircles for the TIN.
If the Vertex numbers item is set, the number of each vertex is displayed adjacent to the vertex.
If the Scalar values item is set, the active data set value of each vertex is displayed adjacent to the vertex.
Texture Map Image
The Texture Map Image Item is used to "drape" an image over the surface of the TIN.
Related Links:
TIN Module