In this example, we will use 3 Groups of points: 2 will contain the points of 2 successive surveys and the 3rd will contain all the points.

Let us start by creating a group by clicking to show the the points Groups management window. There let us create group “LEVE1” and add points to it by importing a coordinates file. This file contains points 1 to 7 of the day 1 survey. We will choose the following layers for these points: “leve1_points”, “leve1_numbers” and “leve1_elevations”. Now let us create group “LEVE2” and add points to it by importing a coordinates file. This file contains points 8 to 17 of the day 2 survey. We will choose the following layers for these points: “leve2_points”, “leve2_numbers” and “leve2_elevations”. Finally let us create the “GLOBAL” group and add points to it by selecting all the points created previously.

We get this :

Points in survey 1 & 2

Created groups

We can now perform various operations : for example, we want to change the elevations of points in group "LEVE2" only. Let us issue the Z modification command ( ), choose to add 100.00, then when the program asks for point selection, issue "G" + [RETURN] then select "LEVE2" .

We get this :

Last example : we want to create a polyline passing through all the points. Les us click , then set the "GLOBAL" group as current by double-clicking its name in the list. Let us issue the POLYLINE command and when AutoCAD prompts "Specify start point", enter "1-17" in the "points number input box". We get this :