WMS:Terrain Data Tools

The following feature object tools are in the dynamic portion of the Tool Palette when the Terrain Data module is activated.

File:Tool SelectVertices.GIF Select Vertices

The Select Vertices tool is used to select vertices for operations such as deletion, or to drag a vertex to a new location. The coordinates of selected vertices can also be edited using the Edit Window. This same tool allows for selection of outlet points on the TIN.

Select Triangles

The Select Triangles tool is used to select triangles for operations such as deletion. In addition to the standard multi-selection options, another type of multi-selection is available with this tool. By holding down the CTRL key while dragging the cursor, a selection line can be entered. All triangles intersected by the line are added to the selection list.

Create Breakline

The Create Breakline tool is used to select one or more strings of vertices. Vertex strings are used for operations such as adding breaklines to the TIN or selecting a string of vertices which will be used to create a stream.

The procedure for creating breaklines is somewhat different than the normal selection procedure. Strings are selected as follows:

• Click on the starting vertex for the breakline. The vertex selected will be highlighted in red.
• Click on any subsequent vertices you would like to be part of the string (vertices do not have to be next to each other). The vertices selected are now connected by a solid red line.
• To remove the last vertex from a string, press the BACKSPACE key. To abort entering a vertex string, press the ESC key. To end a vertex string, press RETURN or double click on the last vertex in the string. Another vertex string can then be selected.

Swap Triangle Edges

The Swap Triangle Edges tool swaps the edges of two adjacent triangles and is usually used to make local adjustments to a TIN. To use the tool, simply click on any triangle edge.

File:Tool CreateVertices.GIF Add Vertices

The Add Vertices tool is used to manually add vertices to a TIN. It can only be used in plan view. When this tool is selected, clicking on a point within the Graphics Window will place a new vertex at that point. What happens to the vertex after it is added (whether and how it is triangulated into the TIN) depends on the settings in the Vertex Options dialog under the TINs menu. These settings can easily be used to digitize elevation data from scanned images of contour data (see Vertex Options).

Create Triangle

The Create Triangle tool is used to manually create new triangles. Triangles are normally created by triangulating a set of points automatically. However, this tool is useful for localized editing and refining a TIN. To use the Create Triangle tool you may either:

• Select three vertices that will form the triangle. The vertices can be selected in either clockwise or counter-clockwise order.
• Drag a box around three vertices that will form the triangle.

The ESC key can be used to abort the creation of a triangle once you have started selecting vertices.

Select DEM Points

The Select DEM Points tool is used to select a region of DEM points to make active or inactive. Coordinates of DEM points may not be edited. When selecting a group of DEM points a rectangle or polygon around the points is displayed rather than trying to identify individual DEM points. To deselect a group of DEM points that have already been selected, click anywhere in the graphics window. Multiple groups of DEM points may be selected by holding down the SHIFT key while dragging a rectangle around the second group.

The Feature Object and Drawing Tools are also available from the terrain data module.

Related Topics

Tool Palettes