Terrain Calculation Dialog

This dialog box is accessed from the Edit - Calculate Terrain Model menu.

Calculate Triangles Checkbox

Causes a new TIN model to be generated.

Remove All Existing Contours Checkbox

If this box is checked all contours are removed. If this box is not checked when contours are generated, existing contours are preserved unless they match the elevation of a contour in the new set.

Create Volume Features Checkbox

If selected, a Surface/Volume Feature will be created. This feature will coincide with the extents of the Terrain Model and will contain attributes related to the surface volume of the model. 

This feature can be used to modify the extents of the TIN model by first editing its shape and changing its properties from Surf/Vol Boundary to TIN Boundary, then re-running the Terrain Calculation. Make sure that you also change the name from "TIN~" or this feature will be deleted next time you choose to "Create Volume Features".

Note: the "+" button beside the checkbox allows you to change the color and line type.

Triangles

Point Selection Button

The point selection activates the Triangle Point Range Selection Dialog which allows you to select a subset of points for triangulation.

Max. Side Length

If this field is filled in, triangles with sides longer than the specified maximum are removed. TIN Boundary features can also be used to control triangulation (see Included and Excluded Areas for more information).

Include All Checkbox

If this checkbox is enabled, all triangles will be included in the computations.

Z-Value

Displays the attribute to be used for contour generation.  Modify by clicking the Change button.

Change

Allows you to choose what value to use for generation of contours.  Normally this would be set to Elevation, but the capability is there to contour any numeric point attribute.

Contours

Smoothing Checkbox

If selected, contours will be smoothed (see Contouring for more information).

Thinning Distance

This field contains the thinning distance in project units (see Contouring form more information).

Major Contours / Minor Contours Checkboxes

If selected, major/minor contours will be generated. If contour(s) already exist for a specified elevation the existing contour is removed before the new one is created.

Note: the "+" button beside the checkbox allows you to change the color and line type.

Major Contours / Minor Contours Tabs

Depending on the current tab setting, the following will apply to either Major Contours or Minor Contours:

Interval

Interval between contours.

Start

Lowest contour elevation - the calculated value below represents the lowest elevation of all points in the Terrain.

End

Highest contour elevation - the calculated value below represents the highest elevation of all points in the Terrain.

Calculated Range

Displays the range of start and end values that are possible in the current file.

Labeling Checkbox

If selected, contour labels will be generated (see Contouring form more information).

First Label Space

Distance along the contour in mm to the first label. E.g. with a value of 5 the first label will start 5mm along the contour line on the output sheet.

Next Label Space

Distance along the contour in mm between consecutive contour labels.