Monday, March 28, 2016

Point to Point Inverse in Civil 3D

I find that map commands in Civil 3D can be very useful for both land surveyors and civil engineering technical staff. The problem seems to be that many users don't know about these very useful commands.

Here's a question than I'm often asked by land surveyors:
Is there a point to point inverse in Civil 3D?

The answer to this question is YES!
CGSLIST + the 'PN transparent command.


CGSLIST is located on the Analyze ribbon tab in the Inquiry panel.


The help information for this command doesn't mention vertical difference, but that information is included in the output for this command.

This command uses the settings for Angle, Distance, and Direction that are stored in the Ambient Settings of the current drawing. If you want the course (bearing) to be in N90°00'00"E format, open the Drawing Settings dialog, choose the Ambient Settings tab, change the Direction > Format setting to DD°MM'SS" and press OK. You can also change the precision for coordinates, distances, and more.

You should also expand the command line so that you can see at least five lines of the command line history.

My example begins with a drawing that contains two points that are exactly 10 feet apart horizontally and 5 feet apart vertically. This allows me to confirm the horizontal and vertical results of the command.

Using the CGSLIST Command

  1. After selecting the Analyze ribbon tab, locate the Inquiry panel and click on the List Slope (CGSLIST) icon.

  2. When prompted, type P and press enter to use the Points selection option. Selecting the Points option here only notifies the command that you want to select coordinate points, not Civil 3D cogo points, for the input data type. 

    NOTE: The command line shows that _AeccCgSList is the command running. You can also access this command by typing CGSLIST at the command line and pressing enter. If you are using Map 3D, use MAPCGSLIST. All three commands work in Civil 3D version 2015 or later. 

  4. When prompted to select a starting point, type 'PN and press enter. This will tell the command that you will be entering Civil 3D cogo point numbers instead of selecting coordinate points by clicking on the screen.

  5. When prompted to enter a point number, enter the starting cogo point number then press enter.

  6. The coordinates of the cogo point will appear in the command line history. Now enter the next cogo point number for the ending point then press enter.

  7. This command reports horizontal distance and elevation difference. It also reports the point elevations along with the grade and slope between the points. Notice that the distance shown is a horizontal distance, not a slope distance which is the result reported when using the DISTANCE or MEASUREGEOM command.

Don't be fooled!

Even though the command shows that the 'PN transparent command is still running, the CGSLIST command has reverted to the original Select object or [Points] prompt. At this point you'll need to press ESC to exit the 'PN transparent command, type P then enter to return to the Points selection, and finally type 'PN and press enter to return to the 'PN transparent command.

If you want a command that repeats with the 'PN transparent command, record a macro. If you're interested in a follow-up blog describing how to create and use that macro, please let me know in the comments section of this posting.


Brad Closson said...

Great job on this. Very helpful.

Brad Closson said...

Enjoyed your post.