How to clip pointclouds using solids?

Hi all,

How would one remove all points that are inside certain 3D regions?

Assume I have no knowledge about the available pointcloud tools!

I imagine it is easily done using Pointools and a 3D microStation DGN with solids describing the cut-volume, or something like that, but I need to be sure what the proper solution is before I trouble our IT department. We already have (some older version of) Descartes.

About our (run-of-the-mill, I presume?) scenario:

We have huge and detailed lidar scans from airplane of about 60km of new infrastructure, including urban areas. We want to cut away the points where our new project is going to be so we can clearly see and visualise the new structures together with the pointcloud. There are tunnels, existing bridges and other features like cables that we want to keep. We have the entire project mapped out as solids and so forth (or can do that fairly easy in microStation)

It is absolutely necessary to remove the points from the project area. We cannot use a solution where there is geometry blending together with the existing points.

Thanks,
Torben, who is promoting pointclouds all I can around here! :)

  • Unknown said:
    I'll check with Bentley Descartes product managers. That might have a better solution to propose.

    Any news on this?

    System: Win7 64bit 16GB Ram - microStation V8i SS3 08.11.09.578. + PoinTools CONNECT. - Intel i7-4800MQ CPU@2.70GHz, 4 core / 8 Logic proc.

  • Hi Torben,

    I have been confirmed that only a limited number of elements are supported by the point cloud clip functionality. Also the mesh element is not supported.

    Another approach proposed by some of my colleague would be to use the clash detection function to detect the points present in solids, but the end result (i.e. : the points not present in solid) will not be exportable into a new point cloud. Also note that the clash detection is not part of the Bentley Descartes license.

    HTH,

    Mathieu



  • Well, it didn't really help Mathieu.

    So In effect there is really no help, in any Bentley tool, to trim pointclouds by elements. And the vanilla install of microStation has pretty much the same tools and options as your dedicated pointcloud apps. I have to admit I am feeling very dissapointed at the moment.

    Also, cencorship in the forums?...

    I submitted a long thread here about my first - not so good to be honest - experiences with poinTools, but was told that I posted in a forum where an admin. needs to approve the post.. This was friday and it is still not posted here. If you guys needs to discuss/cencor what I write before it is posted here, that is fine by me. But just ignoring a post completely, without at least saying why, is not ok. I spend the better part of two hours on that post, and not seing it posted for a dialog is really demotivating.

    Well, I guess it is time to Google for alternatives..

    System: Win7 64bit 16GB Ram - microStation V8i SS3 08.11.09.578. + PoinTools CONNECT. - Intel i7-4800MQ CPU@2.70GHz, 4 core / 8 Logic proc.

  • Unknown said:

    cencorship in the forums?...

    This has been brought up before... the system has a built-in automated moderation ability that is configured to put anything that triggers it in a holding area to be reviewed and subsequently acted upon. This can happen when a certain (large) number of hyperlinks are included, all sorts of different font attribution are used, or certain words or phrases are used (among other things). In your particular case, the first was not an issue, the 2nd one borderline, and the 3rd... well... the 3rd is most likely what caused your post to be moderated (yes, it is something you and I have "discussed" before, and this is what ends up happening). Normally, there is notification sent to site admins and moderators identifying that there are posts waiting in "moderation time out", but for some reason, this did not happen with your post (it is quite possible that this coincided with another post in another area of the site and we simply did not look beyond that one). So for that, we apologize for not seeing that until now. We "cleaned up" your post a little so it could go through, and it now is in this forum.

    For future reference, we recommend not using "coarse language" when posting here -- easing up on the various font attribution is also suggested :).

      

  • Thanks Phil.

    I know you don't censor the forums!

    I am actually pleased that you moderate (my) posts, as nothing good comes from "heated communication" - and I certainly do not want to contribute to that. You guys have indeed told me numerous times to proof-read my posts, and I really try to - trust me :)

    I apologize for any coarse language that might slip my through my fingers in the future and tell myself it has to be because english isn't my first language - and not because I care too much about my software :)

    System: Win7 64bit 16GB Ram - microStation V8i SS3 08.11.09.578. + PoinTools CONNECT. - Intel i7-4800MQ CPU@2.70GHz, 4 core / 8 Logic proc.