Adding source data by grid method entry

The Grid Method Entry command creates a rectangular grid of points on the screen, and prompts you to enter the elevations of those points. The Site Model from Source Data command then creates a topographical model based on those points.

Use this method when the source data is extracted from a paper map. Draw a grid on the map, and then determine the elevation of each grid intersection by interpolation between adjacent contour lines. Use these elevation values to create the grid.

Stake objects inserted with the grid method use the default parameters set in the stake object properties dialog box (see Inserting stake objects). They can also be individually selected and edited after placement.

To generate source data using grid method entry:

Select the command.

When prompted, click at the upper left corner of the grid to set the starting point.

The Point Entry Grid Setup dialog box opens.

Enter the number of rows and columns of points to be created, as well as the distance between the points (Grid Spacing). Specify whether to insert the result type of 3D loci or stakes, and then click OK to create the grid.

The Enter Z Values dialog box opens.

The first point on the drawing, at the upper left hand corner, is automatically selected. Enter the elevation of the point, and click Next. The elevation is applied to that point, and then the second point in that row is automatically selected. Enter the elevation for that point; continue until elevations have been entered for all of the points in the grid, and then click Done.

Site model source data

Validating 3D source data

Simplifying 3D polygons

Creating the site model