Automatic Line between two Points

[AStrasser]

Hello,

during my research on processing point clouds from terestrial laser scans / UAV, I came across the following video:

https://www.youtube.com/watch?v=UzhCcfdFWFg

I like the processing as described in the video very much and it works very well.

Only one "little thing" is still missing.
The automatic generation of the breakline.(Polyline or many Singlelines)
The starting point would be minute 4:30 in the video.

Now I am looking for a function that connects 2 points with a user-defined distance as a line.

The distance would then be the same as in the previous step in the video.

Then I should get a lot of short lines.
Does something like this work?

I would like to save myself the manual drawing between the points.
But I need the lines so that I get clean edges later in CAD when meshing and don't have to constantly rework the triangles.

Many thanks in advance for any tips.


Many greetings,

Andreas

[daniel]

Not sure to fully understand your algorithm... but it reminds me a little about the enveloppe or contour extraction algorithms (that you can achieve with the Cross Section tool: https://www.cloudcompare.org/doc/wiki/i ... ss_Section). Especially the enveloppe extraction that has this 'maximum edge length' concept (the distance between two consecutive polyline vertices).

[AStrasser]

Hello Daniel,

Thank you for your reply, but I don't get it.
I tried it but I don't get the results I want.
It could be that I am not using the tool correctly.
Can you help me a little more precisely?

Perhaps to make my point a little more understandable.
I have a point cloud from a drone flight (see picture 1).
With "Edit" -> "Normals" -> "Compute" -> "Convert to" -> "Dip/Dip directions SFs" (see picture 2) and the slider I find manually the points of the break edges (see picture 3).
I then export them and "subsample" as needed (e.g. every 1 m) and "segment" different areas. (see image 4, e.g. a pile of dirt, traffic circle).

These points I would like to have now either as a polyline or many individual lines, each between 2 points, connected (see sketch image 5) and finally export to CAD that I then get clean edges during further processing and do not have to draw these lines manually.

Thanks in advance for your support


Greetings,

Andreas

[daniel]

Ah, ok. Thanks for the detailed explanation.

Sadly, I don't see how to do this with CloudCompare!

[AStrasser]

Hello,
some time has passed now.
But nothing has changed there, has it?
My problem still has no solution in CloudCompare, right?

I was thinking of something like:
- choose a starting point
- Define distance/radius from user
- the radius is used to search for another point around the starting point
- if one is found, the two points are connected with a line
- the found point is now the starting point and everything starts over

you let this run until you either find nothing more or arrive at the original starting point.

The result should then be either a long polyline or many short lines between two points

[daniel]

Ah, I guess it could work in your case... Are you able to implement/test this strategy on your side?

[AStrasser]

Oh, I like to hear that.
So I can't programm anything, but testing is no problem.

[daniel]

Ah, I meant to test it on your side, by implementing it even in a very dirty way ;)

Otherwise you'll need to motivate someone to do it...

[AStrasser]

That should work.
Thank you in advance.

[AStrasser]

Hi Daniel,

no stress, but I wanted to ask if you already had an idea for the implementation of my topic.