Bryant Quinney | Applications Expert
If you have ever had the feeling that you’ve forgotten something important, then we are all in good company. It seems that I forgot to write a blog for this week, so the “feeling” was well founded.
In AutoCAD Civil 3D, we can import a point cloud and generate a surface from it, using either an RCS or RCP file. The difference is straight-forward, the RCS file is a single Autodesk ReCap scan (which can be either an individual scan or a composite of scans, exported from ReCap). An RCP file is the project file, which may contain multiple scans.
Using a relatively small dataset, “Manitou”, from an E57 file of a scan, I will illustrate working with individual (RCS) or project (RCP) point clouds within Civil 3D. For discussion, I didn’t edit out any features from the file I used to isolate the ground features, so buildings, trees, etc. will be included. The gradient image shown is the result of the complete scan, whether imported as a complete project or each RCS file being imported one at a time. You achieve the same result either way.
When I export the project data from ReCap as an RCS file, I get 1 unified scan file (which will be referenced as “composite”). In saving the project, the RCP that’s created has registered 5 RCS scan files which are referenced.
When importing an individual RCS file, the scan is shown without regions, unassigned points, or scan listing (the image shows my composite scan), since it is a single scan file. Also, if the scan was one of the individual ones used, only that part of the view would show in the drawing window.
However, when I import an RCP file, a group of scans is listed, and each scan is individually identified within the project. They can be turned off or on, isolated, or navigated to separately from the other scans.
Now that we have an idea of the difference between the two import choices, let’s see how that affects our project when generating a surface. Keep in mind that the command to generate a surface expects a single entity to be chosen. If you are using the composite, and that is from what you want the surface to be derived, you’re in luck. You get a single surface from a project level. This is handy if you labored inside of ReCap to resolve any issues or remove unwanted artifacts from the scan. Your result will be more of a finished-level surface, for our existing site, that is.
If you imported each scan independently, you must select each scan to generate a surface. Depending on your data, this may be your better route to take. You can select the scans that are pertinent to your desired surface and select Create Surface from Point Cloud. Civil 3D will then generate the surface based on only the scans you selected. There are only two scans shown (see image) which are from what the surface was generated (contours and triangles shown).
There may be a need to add more scan data if you have already generated a surface from an individual scan. You will need to remove the surface, import the other scans and then generate your surface.
There is no single “right way” to do any of this, when speaking of the methods covered and their differences. It depends on your data and what you are trying to achieve.
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