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Point cloud is not displaying

Posted: Tue Jan 12, 2016 12:49 pm
by SH55
Hi there,

I've been using CloudCompare to undertake comparisons of a series of laser scan surveys. I'm pretty new to using the software and have been very impressed with what it can do; it has all the tools I've needed as part of my project.

However, having just received the most recent laser scan survey I am having trouble getting it to be displayed in the software. The data is sent to me as a csv file. Previously, I have loaded it using File > Open > ASCII cloud and selected the csv of interest. I can still follow this process with no error being flagged up and the file appears in the DB Tree pane. But, nothing appears in the main window except a yellow box. The box can be rotated as normal, but with no points visible. I have tried altering various display settings but with no success.

I have compared the new survey csv with an older survey csv in a text editor and everything looks the same i.e. no change in the format of the file we have been provided. If I remove the new survey (lets call it Survey B), then I can happily load Survey A (an older one). However, if I then attempt to load Survey B again, everything disappears from the window although both Survey A and B are shown as visible in the DB Tree pane.

Via a combination of loading various csv files in different orders I have now managed to load Survey B but cannot do it consistantly. If I close CloudCompare, it is very tricky to undertake the same process of loading and reloading files to get Survey B to open again.

Does anyone have any suggestions? I feel that I could be missing something really simple, but as the same method of loading the point clouds has worked successfully before I am not sure how to go about solving the issue.

Many thanks in advance!

Re: Point cloud is not displaying

Posted: Tue Jan 12, 2016 2:01 pm
by daniel
How strange... What is the version of CC you are currently using?

And what is the size of the problematic cloud by the way?

if cloud A and B are small enough, can you send them to me? (cloudcompare [at] danielgm.net)

Re: Point cloud is not displaying

Posted: Tue Jan 12, 2016 2:49 pm
by SH55
Hi Daniel,

Thanks for the quick response. After I'd posted, I had a closer look at the csv and whilst the formatting is the same as previous datasets we had received, there were a few rogue lines dotted throughout that have an additional number in the x, y and z columns. I have contacted the surveyor to ask if they can provide an amended csv to see if this fixes the issue.

Although the vast majority of the points will be located in the correct spatial location, perhaps having a handful of points located somewhere else is causing a problem with the display? Where I have managed to get both Survey A and B to display, the associated yellow boxes around the clouds are significantly different sizes - would this suggest there are a few points a long way away from the main dataset? I will post once I have a new csv from our surveyor to let you know if this resolves the problem.

I am using v2.6.1 - would you recommend I upgrade to the latest version anyway?

Re: Point cloud is not displaying

Posted: Tue Jan 12, 2016 3:52 pm
by daniel
Indeed, if there are some points very far away from the main point cloud, you will get a much bigger bounding box. The 3D view will zoom out a lot and you won"t see the real cloud anymore.

You can check this by looking at the cloud bounding box (in the properties dialog).