Topography compatibility

Learn how to import, evaluate, and select 3D topographical survey data in PVcase for AutoCAD. This guide covers file requirements, survey data selection steps, and best practices for high-density terrain modeling.

Survey Prerequisites

• Format: Must be a .DWG file with explicit elevation (Z-coordinate) values.
• Layer Hygiene: The terrain layer must contain only topographical data—remove all interfering objects.
• Blocks: If data cannot be selected, run the AutoCAD EXPLODE command first.
• Density: High data point density improves terrain accuracy and automated layout generation.

How to select terrain data

1. Open Layout Generation Settings.
2. Check Topographical layout and click Select.
3. Click an object on your dedicated terrain layer.
4. Press Enter or Space to confirm.

The examples below show the characteristics that differentiate high-quality topographies from less suitable ones. We will focus on the following aspects:

• Height measurements or height numbers
• Contour lines
• Mixed topographies
• Point data cloud
• 3D faces
• XREF Files

 
To learn how to use the online terrain data provided by PVcase, please visit Online terrain import.

If you experience difficulties with your site survey data, please contact our Support team using this form, the chat, or by emailing support@pvcase.com. We will be happy to review the survey information.

Height measurements or height numbers

Good topographies have clear and densely populated terrain indicating objects.

Inferior topographic survey height measurement indications are scattered and filled with other numerical information on the same layers.

Contour lines

Good examples of topographic surveys have contour lines that are densely populated and have the same distances between them.

Poor examples have distances between contour lines that are either excessively large or inconsistent. Furthermore, these lines may lack elevation properties.

Mixed topographies

Some surveys include several different indicative objects, such as contour lines and height measurements. These offer even more precision.

Point data cloud

Any point data cloud is compatible, provided the points include dimensional coordinates as a property. If the data is contained in blocks, you must explode it before using it (see the example below). 

After using the Explode command in AutoCAD, the point object appears with two attributes next to it.

3D faces

3D faces are compatible and can be read successfully, provided they include position properties. 

XREF Files

You can use external topography files as an external reference (XREF) for your layout. This improves AutoCAD performance and also allows two users to work simultaneously using the same XREF file.

Before attaching the external file containing the topography information, it is important to consider the following points:

• Cloud point data is not valid. Only Contour lines and 3D face objects can be used as XREF topography.

• XREF should not include mixed topographical survey data. For example, if you have contour lines and 3D face data, when using XREF, the software will only take into account the one that has more objects.

• The external file must contain only topographical information. Any non-topographical elements in the drawing will be imported into PVcase as terrain data, resulting in an inaccurate terrain model.

• In the main file, place the XREF file on a dedicated layer. When you select the first object representing topography, PVcase reads all components in the layer where this object is placed. If this layer contains other information not related to the topography, PVcase will create a non-realistic model.

Once the external file is clean, you can attach it as an XREF to the main file. Follow the steps below: 

1. Open the XREF manager by typing XREF on the AutoCAD command bar:

2. Attach your contour line topography file:

We recommend working with the same origin point for both the XREF and the new design file. To do that just leave the Specify On-screen checkbox unchecked and make sure that all the coordinates are on 0.00.

3. Once the file has been successfully attached, use the command PLAN from AutoCAD to check the contour lines. This command displays an orthographic view of the XY plane of a specified user coordinate system.

4. At this point, you can use XCLIP to section off a portion of your file to work with. The XCLIP command allows trimming an external reference to a specific area. This is very useful when you are working with a large file that has extra details that you don't need on your current design.

5. After clipping a boundary,  follow the standard procedure for selecting the topography and generating the frames.

When you load your original file as an XREF, PVcase merges multiple topography layers in the file. You will then only need to select one of the resulting layers.

Now you can generate a terrain mesh to double-check that PVcase imported the topography information successfully.

To learn how to evaluate and troubleshoot terrain surveys with the terrain mesh tool, visit Evaluating terrain surveys for generation.