Polyline Vertices command with multiple objects

[ArthurADas]

Hi

Here is the situation, i received a point cloud containing 12milions points. This number makes impossible to work with a surface created from that many points. To simplify that, im planning to use the alignments ticks (because they are perpendicular to my algnment), spaced 20meters from each other, as transversal lines, and from those ticks i would explode them and turn them into lines. Finally i would use the Polyline Vertices command to create gogo points from those lines, but since the existing command doesnt allow me to apply into multiple objects i got stuck.

Now i'm looking for a lisp that has the same objective as the Polyline Vertices but i could use in multiple objects

[jefflambert9091]

Why not convert the lines into feature lines instead of making points? 

[jmayo-EE]

Do you have the raw cloud data and a program like Cyclone or TBC to extract data from the cloud? If so this may be a better way to get out a grid of points, linework or a mesh surface.

If not you may want to try bringing the cloud into Infraworks and have it generate an optimized surface for your work. Civil 3D can then just read the optimized surface from the sqlte database and these surfaces perform very well in Civil 3D.

John

[ArthurADas]

How does converting the lines to feature lines help me?

[ArthurADas]

I actually dont have Cyclone nether TBC, or any software that i could extract data from cloud. But infraworks i do have, im gonna try to use it, thanks for your suggestion

[Pointdump]

Hi Arthur,
Sounds like a huge workaround just to deal with a huge point cloud. Both ReCap and Civil 3D allow you to decimate the point cloud to a workable number of points.
Dave

[neilyj666]

@ArthurADas I'd go with the suggestion from @Pointdump and you can also use the Surface simplification tools in Civil to reduce the surface size still further (and which works very well for all practical purposes). I have also used the free 3rd party CloudCompare utility to manage point clouds but Recap is still required to produce the .rcp file that Civil 3D can understand whereas Infraworks can work with .las files natively.

[ArthurADas]

Seems like the most practical way to deal with the point clouds, since i only have civil 3d available with me. At the end of the day i was able to finally come up with a solution specifically to my problem. I just created an assembly with links and from there i generated a corridor and a report from it. Now i have data from all points settep up exactly where i needed.

But thanks all of you for your attention and suggestion.

Arthur 

[Neilw_05]

Don't the cogo point tools allow you to create points along a polyline at the verticies? Maybe I don't understand the objective. What do you do with the cogo points after you make them?

[neilyj666]

Don't forget that your surface will be based on transects 20m apart which may or may not accurately reflect the topography (given the density of the point cloud) so be wary of errors in volumes.

I would personally use the alignment and create a buffer e.g. 30m each side and extract the pointcloud data within the buffer via CloudCompare so creating a DTM that accurately reflects the point cloud data.

[ArthurADas]

Exactly, they do create points along a polyline at the verticies. The only problem here is that i have more than 500 polylines. Using the Polyline Vertices i would have to click one by one in order to create all gogo points that i need from those vertices. My objective with those gogo points is to create a pattern like presented in the image attached here. Using this idea i going to reduce drastically the number of points from the point cloud, at the same time that i maintain the original elevaction from the point cloud (using the Elevation from Surface tool from gogo points)

[ArthurADas]

I'm keeping that in mind. I'm still deciding if is it better for me to decrease the longitudinal distance to 10m or just add more gogo points on segments that i judge necessary based on the aerial image. 

[neilyj666]

Personally I would have little faith in a DTM created this way especially given the sinuous nature of the alignment...but as I don't know your ultimate objective it may work for your purposes.

How are you getting the elevations if you only have a point cloud?

[Neilw_05 · Accepted solution]

While you did find a solution that works for you, another idea is to draw large polygon areas between your polylines and remove the surface data from those areas. This will leave you with the detailed terrain in strips where you need it. Without seeing your file I won't know if this is a viable idea or not. Just something to consider.

[Jeew-m]

Can't you use THIS method to simplify the surface?

[ArthurADas]

That is a very good workaround, definitely gonna use it next time i have a similar problem. Thank you so much

[ArthurADas]

It could be very useful in another case, but i need those points composing my surface triangulation coming exactly from those vertices, thats why the idea, at first, was to use the ticks from alignment station labels as polylines so i could create gogo points from them.