Topography compatibility

Terrain, Topography, Survey, Contours, Lines, Data, 3D, 3D faces, Compatible

Nerijus avatar
Written by Nerijus
Updated over a week ago

PVcase can operate with a broad spectrum of topographical data, as long as it is in a .DWG file and the data points have elevation (or Z coordinate) values.

It is preferable that the topographical surveys would have densely populated data points which would make for a higher-accuracy terrain. This in turn would result in more accurate layouts and improve the workflow of developing PV area solutions.

Here are some examples of topographies and what separates good topographies from inferior ones:

🛈 If you would like to use PVcase provided online terrain data and you want to learn how to do it, click here:

If you as a client are having some sort of issues with your site survey not working properly - feel free to reach out to support and we will review the survey data.

1. 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.

2. Contour lines;

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 too large or do not have elevation properties and are scattered at various distances between each other.

3. Mixed topographies;

Some surveys consist of several different indicative objects, like contour lines and height measurements. These offer even more precision.

4. Point data cloud;

Basically, every point data cloud is okay to use as long as points have dimensional coordinates as a property. Sometimes data is in blocks, therefore, needs to be exploded for usage (example below).

After using Explode command in AutoCAD, the point object appears with 2 attributes next to it.

5. 3D faces;

3D faces can also be read well as long as they have position properties.

Note: Some 3D faces are made into blocks, surfaces, or Polyface meshes, which need to be converted using the AutoCAD command Explode.

6. XREF Files

XREF stands for external reference, and we can use external topography files as a reference for our layout. This improves AutoCAD performance and also allows 2 users to work simultaneously using the same XREF file.

Before attaching the external file containing the topography information, it is important to have taken the following points into consideration:

  • 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. Anything else in the drawing will be imported into PVcase as topographical data, leading to an incorrect terrain model.

  • In the main file, the XREF file must be placed on a dedicated layer. When selecting the first object representing topography, PVcase will read all the components inside the layer in which this object is placed. If this layer contains other information not related to the topography, PVcase will create a non-realistic model.

We recommend using the QSELECT command to identify contour lines that have zero elevation, or different drawing elements that do not belong to the contour lines themselves.

After having cleaned the external file, we can proceed to attach it as an XREF to the main file:

1- First, open the XREF manager by typing XREF on the AutoCAD command bar:

2- Then 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- After having the file properly attached, just 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, proceed with the conventional processes of selecting the topography and generating the frames:

It is worth mentioning that even if you have more than one topography layer on your original file, after having it loaded as an XREF, the layers are merged together and you need to select just one of them.

One important note is that if you extend the clipped boundary you need to reselect the terrain again for PVcase to read the newly clipped information. PVcase retains the properties of the topographic data at the time of layer selection.

6- Finally, you may now generate a terrain mesh to double-check whether the topography information has been imported to PVcase successfully.

🛈 If you would like to learn how to evaluate and troubleshoot terrain surveys with the terrain mesh tool, click here:

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