Build Constraints From Database Lines

Modify a "constraints" grid at locations defined by a line in a database (e.g., seismic line). You can specify one of seven tool shapes (e.g. cosine) and the height and width of the tool perpendicular to the line path.

To create a new constraints grid, run the New Constant Grid dialog and set the constant grid value to 1. Then, run the Build Constraints from Database Lines (NGASCONS GX) on that new grid using a tool height of –1. If the line crosses itself, the GX uses the smaller of the two overlapping values.

If you start with a grid with all the values in the grid set to 0, the function will make no changes in the grid.

To Build Constraints from Database Lines

On the GM-SYS 3D Tools menu, select Grid Editing.
Select Build Constraints from Database Lines. The Build Constraints from Database Lines dialog appears.
From the drop-down list, select the name of a valid Geosoft floating point Grid to edit. Note that this grid need not be displayed on the current map. Alternately, you can browse to the grid.
From the drop-down list, select the Line database containing the line path.
From the drop-down list, select the Edit tool. This is one of 8 shapes that determine the shape to be used. Each tool is centered at the point. All of the tools except "constant" add the "tool height" modified by the shape to the grid cells in the edit area. "Constant" sets the cell values to the "tool height" value in the edit area.
Enter the Tool height in Z-Units, as specified by the value of the grid. The default value is –1.0.
Enter the Tool width in Ground Units, as specified in the Data view of the map. All tools with the exception of the "square-wave" and "constant" taper to zero at this width.
Click OK. The Line Data Base dialog opens.
From the drop-down list, select the database Line. Only one line from the database will be processed.
From the drop-down list, select the X-coordinate channel.
From the drop-down list, select the Y-coordinate channel.
From the drop-down list, select an optional Mask channel. If the value in this channel is a dummy or zero, that point will not be processed. Any other value in the Mask channel cause the point to be used.
Click OK. The grid appears.