Working With Point Groups In Civil 3D

 The most basic piece of information in the civil design world is the point. Learn more about working with Point Groups in Civil 3D.

What Is a Point?

A group of points

A point consists (generally) of five basic pieces of information that are commonly referred to as a PNEZD file:

  • Point Number – An identifier so you can differentiate between points
  • Northing – The North or “Y” coordinate location of the point
  • Easting – The East or “X” coordinate location of the point
  • Z Coordinate – The elevation of the point
  • Description – A shortcode that tells what type of point you have (tree, utility pole, etc.)

Surveyors go out into the field and collect all the existing site information for your project as a series of points in a data collector, which can be exported to a text file, then imported into Civil 3D where the points are created as physical objects within your drawing. Breaking it down to its most simple level, you can then play connect-the-dots with these points to draw the physical linework that becomes your plan. For example, you can draw a polyline connecting all the edge-of-pavement points to delineate where your road is. Simple, right? Well, maybe not quite that simple. The problem is that surveyors can collect tens of thousands of points across a single site, which makes finding the right points to connect together with your lines a drafter’s nightmare.


What Is a Point Group?

point groups dialog box

That is where Point Groups come in. Point Groups are named filters that bundle your points into manageable pieces that you can turn on/off as needed. They are very similar to layer filters in that you can show only the points you need to work with at any given time. In the previous edge-of-pavement example, it would be much easier if the only points we could see where the EOP shots so make a Point Group that consists of just those points and turn off all the other points. Luckily, Civil 3D makes creating Point Groups a very simple process. You can create a Point Group from your Toolspace, by right-clicking on the Point Group Section and selecting the NEW option. This brings up the Point Group Dialog Box.

The Point Group Dialog Box

Point Group Properties

This dialog is the primary interface for creating your Group. With it, you have total control over what points do and do not appear in your group, what layers they’re drawn on, their display and label styles and most anything else you can think of. Here’s what you can do on each tab:

  • Information: Set the group name, display style, and label style
  • Point Groups: You can nest other groups together to create larger groups
  • Raw Desc Matching: Create groups using the raw codes the surveyors used in the data collector
  • Include: Include points based on number, elevation, name, etc.
  • Exclude: Exclude points based on number, elevation, name, etc.
  • Query Builder: Lets you search through the point data for specific points to add to your group
  • Point List: Shows all the points in your file that belong to your group
  • Summary: A tabular summary of all your point group filters

Using Point Groups

Using a Point Group

Once you’ve created your point group(s) they appear in the Toolspace as an ordered list. The list is very important because the order of the point groups determines which is displayed and which are not.

By default, Civil 3D has two Point Groups already defined in your drawing: “All Points” and “No Display”. Both groups include every point within your file by default, the difference being that the “No Display” group has all the style and label visibility settings turned off. In the ordered list of your point groups, they display from top-to-bottom. This means that if the “All Points” group is listed first, then every point in your drawing shows on screen. If “No Points” is on top, then no points show at all.

In the example above, only my Top/Bottom of Wall points will show on screen because the "No Display” style is right below them so all other points underneath them don’t show at all.

Controlling Point Group Display

Point Group visibility

You control the order, and hence the display, of your Point Groups by right-clicking on the Point Groups section of the Toolspace and selecting the Properties option. The dialog that comes up (above) has arrows on the right side that let you move groups you select up/down in the list. Just move groups you want to work with above the No Display group and all others beneath it and say OK to the dialog. Your drawing will change and you can work with only the points you need.