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Buried Civil 3D tools: Surface Working Plane

Buried Civil 3D tools: Surface Working Plane

By Leo Lavayen, Civil Applications Expert

Civil 3D installs with many tools that are not loaded by default, some of these can be found in the Program Files directory:  C:\Program Files\Autodesk\AutoCAD 2024\C3D\Sample\Civil 3D API.

In that directory many subfolders can be found with fun tools.  Let explore ONE of the many hidden treasures: Surface Working Plane.  It is an incredible tool that make creating simple temporary planer surfaces easy.

I worked with the technical guy that helped in the creation of a grading routine over a decade ago that Autodesk then added to Civil 3D base installation.  I forgot when it started shipping with the software base installation, but glad it is still there.


First step is loading the tools.  Start the APPLOAD command and browse to the installation folder, select and load the tool.  The path is to the Program Files directory, shown below it the path for 2024:  C:\Program Files\Autodesk\AutoCAD 2024\C3D\Sample\Civil 3D API\COM\Vba\SurfaceWorkingPlane

Next, let’s look at the macro tools this loaded VBA routine give us access to.

Found in the same base installation folder is a Readme text file that can help with details:
C:\Program Files\Autodesk\AutoCAD 2024\C3D\Sample\Civil 3D API\COM\Vba\SurfaceWorkingPlane\ Readme.txt
Directly from the Readme text file, here a some detail of the loaded macros:

  1. WorkingPlane.DefineBy2Point:  This macro defines a temporary planar Civil 3D surface given a starting point, flow direction and grade.
  2. WorkingPlane.DefineBy3Point:  This macro defines a temporary planar Civil 3D surface given 3 points.
  3.  WorkingPlane.Resize:  This macro allows you to resize the existing working plane surface so that it is large enough to include the newly picked 2d point, while maintaining the existing origin and grade.
  4. WorkingPlane.Move:  This macro allows the existing working plane to easily be moved while translating a key point on the surface to a new location.

Now, with the tools loaded let’s dive into how to call for the commands.

Again, looking at the Readme text file, macros have a command line version:

-vbarun WorkingPlane.DefineBy2Point
-vbarun WorkingPlane.DefineBy3Point
-vbarun WorkingPlane.Resize
-vbarun WorkingPlane.Move

Another option is to access the commands using VBARUN command and select from the dialog:

Finally, is to put the commands to work.


A simple scenario will be used to show the Surface Creation macros, the idea is to create a temporary plane that will help with setting design elevation points.  The commands create a real Civil 3D surface called “Civil3D_Temp_WorkPlane”.  The surface is considered “temporary” because that same surface is reused every time the macro tools are used.  To keep the surface, simply rename it before running one of the “DefineBy” macros again.

Something else that is created along with the surface is the Surface Style that is assigned to the newly created surface named “Civil3D Temp WorkingPlane

Both surface creation commands run through a Point selection that also offer the “Surface” keyword option allow you to set the elevation of the selected on screen locations (x,y,z) and also offer the option to use a specified surface.  The command also steps through a slope option, by default it calculates from the selected points it also allows for user input.

-vbarun WorkingPlane.DefineBy2Point

-vbarun WorkingPlane.DefineBy3Point

The size of the created temporary surface is related to the selected locations on the screen.  If the surface is too small or needs to be relocated there are macros that can do that too (as shown in section 3 above):

-vbarun WorkingPlane.Resize
-vbarun WorkingPlane.Move

The commands automatically select and edit the created surface from the command “Civil3D_Temp_WorkPlane”.  

From what I can tell, the tools are not meant to create a Final Grading surface, but to provide tools to quickly establish proposed elevations. 

I hope these amazing Surface creation tools take your grading designs to another level!


Leo Lavayen, Civil Applications Expert

As an Applications Expert, Leo is responsible for supporting, training and implementation of software for survey and civil engineering professionals. He has more than 17 years of experience helping large and small, public and private clients in the eastern United States.