PVcase is able to work with any sort of site survey or topography that is presented in a .DWG format and has an elevation parameter or Z coordinates.
If you as a client are having some sort of issues with your site survey not working properly - please contact us & we will make it applicable.
Generally, the best topographical surveys are with densely filled terrain defining objects. Working on these topographies results in more accurate layouts and smoother park development. Below you can find a few examples of good and bad topographical surveys.
1. Height measurements or height numbers;
Good topographies - these topographies have clear and densely populated terrain indicating objects.
Bad topography - height measurement indications are scattered and filled with other numerical information on the same object.
2. Contour lines;
Good topographies - contour lines are densely populated and have the same distances between them.
Bad topographies - distances between contour lines are too large or don't have elevation properties and are scattered in 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 good 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.
Currently, only contour lines can be used as information from an XREF file, and also only a clipped area is used from XREF terrain.
Before attaching the external file containing the topography information, it is important to have the following points into consideration:
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 into 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 XCLIP a portion of your file to work with. The XCLIP command allows trimming an external reference to a specific area. This is super 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 to the ordinary processes of selecting the topography and generating the frames:
It's 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 you extend the clipped boundary you need to reselect the terrain again for PVcase to read the newly clipped information.
6- Finally, you can generate a terrain mesh to double-check whether if 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: