Introduction
Looking for an easy way to use your survey data to create terrain models in the desired form, like a Civil 3D Surface or a TIN Mesh? With Plex-Earth, you can use the topography data handed to you from your survey team, either as elevation points or contour lines, to create surface models in your AutoCAD. Below the necessary steps are presented on how to create surfaces from drawing objects, using Plex-Earth, for two different cases: create a surface using points and create a surface using contour lines.
The "Terrain from Objects" Command
How to Create Surface from Points
How to Make Surfaces from Contour Lines
Create Terrain from Objects
We can locate the respective command on the Plex-Earth ribbon in AutoCAD or BricsCAD, by expanding the Create Terrain icon, in the Contextual Data section.
When selecting this command, we are prompted to choose the following objects in the command line:
- Points: elevation point for surface creation
- Breaklines: contour polylines or lines
- Boundary: outlook boundary line or polyline of the surface
- Holes: line or polyline outlook of a hole in the surface
Using Points and/or Breaklines is mandatory, as they contain the elevation data of our surface. Failing to provide any data for these options, the command will stop proceeding. Boundary and Holes are optional but quite helpful for better shaping your Surface.
To add the drawing data for each option, when the respective type appears in the command line, select the objects and hit enter. If no data exists for these two categories, just hit enter to move to the next option.
How to Create Terrain from Points
In this case, we have survey points in our AutoCAD drawing. Please, note the magenta polyline which will act as the outlook of the area we do not want to include in our surface (hole).
We select the Terrain: From Objects command. Firstly, we are prompted to select Points. We select with our mouse all the points and hit Enter.
In the next steps, for Select Breaklines and Select Boundary, we just hit Enter, since we do not have any specific information for these two options.
In the last step, Select Holes, we select the magenta outlook polyline and hit Enter.
Now, our surface is created!
It will appear like any other terrain object in our Collection Manager and we can use all the Plex-Earth Terrain Editor Tools as well.
For better visualization of our results, first, we can switch AutoCAD's visual style to Realistic. Then, we will go to the Edit tab of our Terrain Editor and choose to Insert as TIN Mesh.
As such, the hole we defined before, is clearly presented in our created mesh.
How to Make Surfaces from Contour Lines
In this case, for our area, we have the contour lines as polylines in our drawing and we want to use them to create a surface. We also have a polyline that will act as a boundary (green color) for our surface.
We select the Terrain from Contours command from the Plex-Earth ribbon. In the first step (Select Points), we just hit enter, as we do not have any.
Then we are prompted to select the Breaklines. We select all the contour lines and hit Enter.
In the next step, Select Boundary, we choose the respective polyline (green) and hit Enter. Then, for the Select Holes option, we just hit Enter, as again, we do not have any.
Now, our surface is created and added, as in the previous case, to the Plex-Earth Terrain Manager. Keep in mind that we have hidden the initial contour lines for better visualization of the terrain construction.
As in the previous case, we Insert a Tin Mesh and switch to Realistic mode for better visualization.
Conclusion
With Plex-Earth, not only do you gain access to high-quality 3D terrain data but, at the same time, you are able to create surface models from your own survey measurements, straight from the field, by using contour lines or points.
We hope that you have found this tutorial on creating terrain, helpful. Feel free to contact us at support@plexscape.com for any questions you may still have.
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Compatibility includes:
AutoCAD, Civil 3D®, AutoCAD Map 3D, AutoCAD Architecture, AutoCAD Electrical, AutoCAD Mechanical, AutoCAD MEP, AutoCAD Plant 3D: 2026 , 2025 , 2024 , 2023 , 2022 , 2021 , 2020
BricsCAD (Pro, Mechanical, BIM, Ultimate): V25 , V24 , V23 , V22 , V21