C3d 2016 Point Clouds

Trimble Realworks here.

Norman Oklahoma, post: 336799, member: 9981 wrote: Any of you who are using C3d 2016 to process point clouds - I am wondering about the functionality. Any comments?

Hi Not sure if this answers your question. I don't process raw data, but use Lidar data from our local council, download titles of data from a web link as .las files. The procedures that I use based are based on the data files and our ANZ country template, it seems very simple in 2015 and 2016.

Basically set up drawing with correct projection, add boundary data and images.

From Active drawing view or ribbon, Create point cloud, add Source data

Add LAS files (Ensure that you select ground data files)

Select coordinate zone (base data from MDC NZTM) Use ANZ_LIDAR point Classification NOT (BY LAYER) this does not seem to work, ie no contours.

Will process point cloud‰Û?. May take some time‰Û?.

Add to surface

Tidy surface remove any extraneous triangles, create a boundary, 3D view for any gross errors.

When then run our own additional quality control checks with any data that we have from control points and or GNSS surveyed points, surfaces.

Thanks kotuku4.

Just to be clear, I'm not talking about registering point clouds in C3d, I'm talking about extracting map-able data from it.

Once you have a surface in Civil 3d you can use it like any other. What map-able data do you want to extract?
I have modelled existing quarry sites for future development and haul roads, created water storage reservoir designs, simple site layout with lots and contours.

I'm thinking in terms of extracting points and/or linework from the point cloud data in order to construct a normal drawing familiar to engineers. A surface is part of that, but only a part.

kotuku4, post: 336866, member: 8886 wrote: Once you have a surface in Civil 3d you can use it like any other. What map-able data do you want to extract?
I have modelled existing quarry sites for future development and haul roads, created water storage reservoir designs, simple site layout with lots and contours.

What is the maximum area you have dealt with? We have a 90 square-mile project coming up...

We use Lidar point cloud data constantly, it's pretty much replaced field survey or using old contour maps for large area surfaces where precise elevations are not critical. The important thing is to know what data is included in the file; is it full-feature, bare earth or model key points? Is there Classification data attached to each point? How about RGB or intensity values?

If I only want point data for a surface then I typically ask our mapping department for space delimited ENZ text files. For a smaller area where I need detail I'll get bare earth, otherwise I use model key points only. C3d can handle millions of points using this method without significant issues.

If I want to use the point cloud for display then I'll probably ask for an LAS file with classifications. The example above shows an area with a river on the left, some trees and low vegetation along the bank, and several buildings on the top of the bank. You can also see the power lines (missclassified as high vegetation.) I can add this point cloud data to a surface, but the rule is that all of the data currently being displayed by the cloud style gets included. I would have to turn off everything except Ground points first.

Jim in AZ, post: 336869, member: 249 wrote: What is the maximum area you have dealt with? We have a 90 square-mile project coming up...

Sorry have only worked on small projects, covering 1-3 square km. About 3 million points, looks to be high density high accuracy Lidar.
The data was collected for Rivers modelling and monitoring, but provides some coverage of local developed area (Wairau Plains) and rural sites adjacent to mapped rivers.

I'm located in a small town, Blenheim New Zealand.

In terms of extracting data from a surface, we use contours, create sections, can add labels or create points from surface.
Images can be draped. I tend to trace polylines of features that I need over small areas, and let the countours and or backround image show everything else.

In terms of points clouds you can alter density of display, add colourization and extract some geometry, but I haven't attempted this.

I think we're talking apples to oranges, if I understand correctly, Norman Ok is interested in info about extracting line-work from point clouds gathered mostly from ground based scanners, not surface data from aerial lidar. I am interested in any comments regarding this as well.

Randy