Create Terrain: Import Elevation Data in AutoCAD/Civil 3D

Import real-world 3D terrain (elevation/topography) into your drawing using Plex-Earth by defining your area and generating terrain as contours, mesh, points, or a Civil 3D surface in AutoCAD/Civil 3D/BricsCAD.

The Create Terrain command allows you to import elevation data and generate a 3D terrain surface for your project area. This helps you visualize topography, model real-world ground conditions, and create terrain deliverables such as contour lines, TIN mesh, elevation points, or a Civil 3D surface.

Step 1. Specify Terrain Cover Area

Go to the Plex-Earth ribbon → Contextual Data → click Create Terrain. Alternatively, type  PXV_TERRAIN in the command line.

You can enter coordinates using:

• Enter or paste the geographic coordinates (Latitude, Longitude)

• Paste from Clipboard

Alternatively, you can define your area using one of the available options shown in the window, such as:

• By Google Earth

• By Point

• By Rectangle

• By Polygon

• By Route

By Google Earth

This option lets you use a Google Earth object to set your project area using a copy-paste method exclusive to Plex-Earth.

1. Choose the By Google Earth option and follow the instructions in the next window.

2. In Google Earth, right-click your placemark / polygon / path → Copy.

3. Return to CAD, click Identify copied area → Accept. 

4. In the Collection Manager palette (left side), confirm the area and click Next: Create Terrain.

By Point

Use this option to define the terrain area from a single point in your drawing.

1. Click By Point.

2. In the drawing, click the point that represents your area of interest.

3. In the Collection Manager palette, confirm the area extents and click Next: Create Terrain.

By Rectangle

Use this option to define the terrain cover area by drawing a rectangular boundary.

1. Click By Rectangle.

2. Specify the two opposite corners of the rectangle in the drawing.

3. In the Collection Manager palette, confirm the selected coverage area and click Next: Create Terrain.

By Polygon

1. Click By Polygon.

2. Select the closed polyline that will act as the boundary clipping for the terrain surface. There should be an existing polyline made of at least 3 points, and preferably closed for optimal results.

3. In the Collection Manager palette, confirm the selected coverage area and click Next: Create Terrain.

By Route

1. Click on the By Route option → select the existing polyline you want to use as the corridor centerline.
2. Define the corridor’s swath width → Accept. The swath width refers to the width of the area spanned by a linear feature, such as a road, highway, or railway, measured perpendicular to its direction.

3. In the Collection Manager palette, confirm the selected coverage area and click Next: Create Terrain.

Custom Terrain Resolution for Google Elevations

To set a custom resolution, instead of automatic mesh calculation, you can:

• Go to Collection Manager → Terrain tab → Options, or

• Run PXV_TERRAIN_PROVIDERS, click the gear icon

Then, untick Automatic mesh calculation, and set your resolution.

Step 2. Select the Surface Type to Insert

After specifying the cover area, a window will pop up to select the surface type to insert:

You can select the following options:

• AutoCAD/BricsCAD Objects:

  • Contour Polylines

  • TIN Mesh

  • Points

  • Civil 3D Surface (for AutoCAD Civil 3D only)

• Advanced Modelling:

  • Terrain Model

Option 1: Inserting AutoCAD/BricsCAD Objects (Polylines, Mesh, Points, C3D Surface)

Choose this option when you want a terrain result that becomes standard CAD content or static CAD objects immediately (useful for offline work or editing with native CAD tools). For more customization of terrain models using Plex-Earth tools such as terrain analysis, terrain labeling, etc., refer to Option 2.

• Contour Polylines: Automatic calculation computes intervals based on area size; manual mode lets you set base elevation and minor/major intervals. 

  

• TIN Mesh: Inserts a mesh for the selected area.

• Points: Inserts elevation points for the selected area.

• Civil 3D Surface: Creates a new Civil 3D surface (Civil 3D only).

Option 2: Inserting a Dynamic Terrain Model (Advanced Modelling)

The created terrain model is imported as a dynamic Plex-Earth element in contour polyline form. They are dynamic in the sense that they can be constantly modified when certain parameters are changed through the software. The dynamic terrains saved in the drawing are also restored from our servers, but can be inserted as CAD objects for offline use.

This can be useful if you want to experiment and make changes or customizations to the terrain several times before inserting a static CAD object for it. 

With a dynamic terrain, you can also insert labels (contour, slope, elevation, direction labels) and perform terrain analysis.

Once the customizations are done, the dynamic terrain can be inserted as static CAD objects like in Option 1 (contour polylines, mesh, points, Civil 3D surface) as blocks, by default, via the Insert button:

The inserted blocks can be edited using CAD tools and can be exploded, if necessary,  but has to be inserted as static CAD objects first.

As such, when a drawing file is saved, the inserted CAD objects are not reloaded from Plex-Earth, as they are stored within the drawing as CAD elements; thus, the user can work with them offline or outside a Plex-Earth session.

For example, in the above image, we see the terrain inserted as a TIN Mesh and displayed as a Mesh (Group) in the AutoCAD properties.

Terrain Editor (for Advanced Terrain Models only)

When a dynamic terrain model is imported, like in Option 2, the Terrain Editor palette will show up in the CAD workspace. This will let the user customize the dynamic terrain even further to better suit their needs.

Parts of the Terrain Editor:

• Terrain Name (red) - Displays the name of the terrain. Double-clicking on it lets you rename the terrain by typing the new name in AutoCAD’s command line.

• Remove (bright green) - This completely deletes the displayed terrain.

• Insert (yellow) - This button lets users insert static AutoCAD objects that will remain in the drawing even out of a Plex-Earth session.

Contour polylines: Inserts a block containing contour polylines, which can be exploded into single polylines. If labels were inserted, these will also be exploded into individual MTexts.
TIN mesh: Inserts a TIN (either polyface or mesh object) as a block that can be exploded into several mesh tiles by range.
Points: Inserts a block containing point objects that can be exploded into single points.
Civil 3D surface (for AutoCAD Civil 3D only): Inserts a Civil 3D surface for the dynamic terrain in the drawing.

• Tools (green) - This option helps users access the Drape Image and Snap Objects commands. 

Drape Image: The ability to combine an image and terrain and create 3D, realistic representations.

Snap Objects: The ability to snap DWG objects to imported terrain.

• Hide (black) - This button hides/shows the dynamic terrain.

• Zoom to Object (white) - This will allow AutoCAD to zoom to the extents of the respective terrain.

• Send to Back/Bring to Front (cyan)- This will send the dynamic terrain to the back or front of the drawing.

• Explorer (purple) - This displays basic information about the terrain. This section may be updated when an inquiry is performed. 

• Contours (blue) - This section lets the user change the parameters of the contours.

• Labels (orange) - This button will show different options for labels for elevation contours. For more details on Label creation, check this tutorial.

-Create: This button enables the user to create labels for the Contours, Elevation Analysis, Slope Analysis, or Direction Analysis.

-Remove: This button enables the user to delete specific labels.

• Analysis (brown) - This section gives the ability to set parameters for performing a terrain analysis. For more information on how to perform terrain analysis, check out this tutorial.

Collection Manager

All dynamic terrains created in a drawing can be accessed from Plex-Earth's Collection Manager. To open it, click on the "Show Collection Manager" button on the Plex-Earth ribbon, as highlighted below:

The Collection Manager palette will pop up, and it will display the Terrain Tab as well, among the others. 

By clicking on it, a list of all the terrain objects contained in the drawing with be shown.

Parts of the Terrain Collection Manager:

• Add New Terrain (red) - With this button, you can Add New Terrain or create a new Surface.

• Hide (black) - This button hides/shows the dynamic terrain. Keep in mind that the Hide button on top hides/shows all Terrains on the list. 

• Remove (blue) - This completely deletes a terrain/surface from the list.

• Zoom to Area (brown) - This will allow AutoCAD to zoom to the extents of the respective terrain.

• Rename (white) - Displays the name of the terrain. Double-clicking on it lets you rename the terrain by typing the new name in AutoCAD’s command line.

• Toggle Auto-restore (orange) - Lock to automatically restore the item on drawing open, unlock to disable auto-restore. 

• Edit (pink) - This will show the Terrain editor.

FAQs