By Michelle Rasmussen
Thank you to everyone that attended the "Working with Point Clouds in AutoCAD 2016" webcast on Wednesday, April 15th. As promised, you can replay the webcast by clicking the link below. Below the video link are the questions that came up during the presentation along with answers to them.
One thing that I failed to make clear is that point clouds do not come from traditional survey instruments. Point clouds come from laser scanners and other reality capture technology. The more dense the point cloud, the more accurate your linework will be.
QUESTIONS and ANSWERS:
Q: Does this only affect the point cloud, or all dwg contents?
A: Creating linework automatically is only off of the point clouds when you use the tools I demonstrated in the webcast.
Q: So do the sections actually work? :)
A: Yes, the sections do work. However, the sections are only accurate if you have a point cloud that is dense enough to create linework from it. Also, make sure that your point clouds do have segmentation data.
Q: Please repeat the file formats again (at the end), also Visualization/Classification - what process or software (Lidar process?) enabled the ground verse the building colours
A1: The file formats are .rcp (ReCap Project) or .rcs 9ReCap Scan). You will create these files by opening Autodesk ReCap, importing the point cloud file(s), then save the point cloud project or scan file.
A2: Setting the classification for points within a point cloud happens during the collection process. This process will be different depending upon which laser scanning instrument is used. So check with the manufacturer of the equipment being used.
Q: You have info from outside the building and inside the building. did you combine 2 point clouds prior?
A: Yes, I combined multiple scans within Autodesk ReCap. Then I saved the file out as an .rcs in order to bring it into AutoCAD.
Q: How do I get the Point cloud Tab. I have the AutodeskFeatureExtraction.msi. Do I need to open a point cloud first?
A: The Point Cloud ribbon only appears if you have a point cloud in the drawing that you can select. Once selected, the contextual Point Cloud tab should appear. If it does not, press <Ecs> to release all selected objects. Then select only the point cloud.
Q: Does object snap cycling work with PC snaps? I have 2014, I guess I need 2016
A: You do need to have 2016 to gain access to the point cloud object snap modes. Unfortunately, object snap cycling with point cloud snaps does not work at this time. You may want to become a member of AUGI and add that to the wish list for Autodesk to make it work.
Q: What's the most accurate, compatible format outputting from a Total Station, LAS file?
A: Total Stations do not create point clouds. Unless there has been a recent change in technology that I am not aware of, you will need to look into reality capture technology to help you create point clouds rather than rely on a total station.
Q: Is this available in Revit as well?
A: I know that Revit does have to capability to incorporate point clouds into Revit models. Unfortunately, I am not a Revit expert and will have to have ASCENT's Revit expert Martha Hollowell comment on that when she returns to the office next week (I wrote this after she had gone home for the weekend).
Q: You mentioned that the edge, corner, & centerline extraction capability is new. Confirm, I don't have this yet in C3D 2015?
A: Correct, the extraction panel of the Point Cloud tab is new to the 2016 software. In the 2015 software you had access to only 3 point cloud object snaps which included:
- Node
- Nearest to plane
- Perpendicular
Q: Can you elaborate a little on the e-learning bundles that you offer? Thanks!
A: The AutoCAD eLearning bundle includes:
- AutoCAD/AutoCAD LT Fundamentals
- AutoCAD Advanced
- AutoCAD 3D Drawing & Modeling
You can learn more about our eLearning bundles at: http://www.ascented.com/courseware-solutions/elearning
Q: How to remove top of trees or bldg point to get existing ground only?
A: If you are using regular AutoCAD, then you would have to create crop regions to isolate existing ground points. However, there are new tools available in AutoCAD Civil 3D that help you remove tree and building points using various algorithms.
Q: What is main advantage of using point cloud.
A: The main advantage is that you can quickly create accurate 3D linework for existing conditions from laser scans and photographs. Engineering and survey firms have used GPS and Total Station survey instruments for years to accurately capture existing conditions. However, the linework they create from it is usually only contour data for the existing ground surface and objects that touch the ground. Point Clouds allow you to work more efficiently and accurately in all three dimensions.