Problems with Point Picking on Point List or Trace Polyline

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JoeKan
Posts: 25
Joined: Fri Nov 29, 2019 11:58 pm

Problems with Point Picking on Point List or Trace Polyline

Post by JoeKan »

Hi All,

I'm having a problem with Point Picking when using "Point List Picking" or "Trace a Polyline by Point Picking".
But I am NOT having problems selecting single points when using "Point Picking". Seems that when I try to create a list or a polyline from points, it is difficult to select the first point and then next to impossible to select any additional points.

I'm using V2.12.4. Am I the problem or could it be something else? I place the index finger of the cursor over or just under the point I want to pick and left-click, but nothing happens. Doesn't matter if I am zoomed in or zoomed out.

Any suggestions on what to try?
Thanks.
daniel
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Re: Problems with Point Picking on Point List or Trace Polyline

Post by daniel »

That's a bit strange...

But the good thing is that many things have changed relatively to point picking in the the 2.13.alpha version.

First you can select a 'cross' cursor instead of the hand (should be the default now, but you can force it in the 'Display parameters' dialog).

And I have worked a little bit on the multi-threading strategy when picking points. Once again, you can also try to use the 'octree' for point picking, or the brute force version (which might go faster if your processor has a lot of cores). You can also control that in the 'Display parameters' dialog ('Auto compute octree for picking' option).

If you reproduce the issue with the 2.13.alpha version (and especially with a specific set of parameters), don't hesitate to report back on this forum!
Daniel, CloudCompare admin
JoeKan
Posts: 25
Joined: Fri Nov 29, 2019 11:58 pm

Re: Problems with Point Picking on Point List or Trace Polyline

Post by JoeKan »

Thanks Daniel. I'll try the ALPHA version.
Question - Can 2 versions of CloudCompare co-exist together? (ei) A stable production version and the Alpha/Beta version?
Lol... Yeah - I should just "try" it... :)
JoeKan
Posts: 25
Joined: Fri Nov 29, 2019 11:58 pm

Re: Problems with Point Picking on Point List or Trace Polyline

Post by JoeKan »

No - You cannot have 2 versions of CloudCompare installed at the same time (anymore). You used to be able to.

Now - When you try to install a second version of CloudCompare, you are NOT prompted for an install directory as you were in the first install. When you run the second version, it overwrites the first installed version even though the first version might have a uniquely named directory. In the earlier versions, you could specify each install directory of CloudCompare so there were no conflict and overwrites.

I tried it both ways - installed 2.12.4 first, then tried 2.13.alpha - the newer 2.13.alpha overwrote the 2.12.4 version. Reversed it, same thing.
JoeKan
Posts: 25
Joined: Fri Nov 29, 2019 11:58 pm

Re: Problems with Point Picking on Point List or Trace Polyline

Post by JoeKan »

Hi Daniel,

Some feedback on the Point Picking. Yes - in 2.13.Alpha it is easier to pick points for both the Points List and Trace Polyline. Yes - I like the methodology.

However, I did run into some problems - while picking was generally easy, sometimes a point just wouldn't want to get picked no matter how I tried. The point right next to it - no problem. I tried this in 'Classification' Scalar Field and also in "Intensity" Scalar Field. I noticed right away that this makes the picking points a lot of work as you cannot trust the snap of the cursor to pick up the desired point and you need to keep trying.

Unfortunately, if the snap does not pick the point after 2 clicks, it won't pick it up at all. I tried on one point several times - there we no other points in the vicinity yet the cursor would not pick the point.

At this point, I took your advice and activated the "Autocompute Octree for picking" option and set it to "Always". That seems to have solved the problem for the most part as 'picking was easier, however, the odd point still refuses to be picked. This seems to be harder in the "Points List" while the "Trace Polyline" seems to be easier. I wonder if this may have something to do with the 'gravity' with which the cursor gravitates to the closest point???

Can the size of the picking cursor be adjusted? I'm finding it's pretty thick and would like to thin it down so it is capable of accurately picking points from a greater distance from the point cloud. Just what is the relationship of the cursor center to the point location? How accurately must the center of the cursor be over the point? There must be some kind of 'closest point' logic at play here.

Looks good so far - I'll pipe in with more comments as I play with it more.
Thanks.
daniel
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Joined: Wed Oct 13, 2010 7:34 am
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Re: Problems with Point Picking on Point List or Trace Polyline

Post by daniel »

Sadly the cursor is a system default cursor, and it's not easy to change...

What you describe is a bit weird, so I'd like to ask 2 questions:
- what's the 'snap' of the cursor you are speaking about?
- by any chance, are the coordinates of the points large? And if yes, have you accepted to apply a Global Shift? (as otherwise, the display will be highly accurate, and where the points lie won't correspond to their actual coordinates)
Daniel, CloudCompare admin
JoeKan
Posts: 25
Joined: Fri Nov 29, 2019 11:58 pm

Re: Problems with Point Picking on Point List or Trace Polyline

Post by JoeKan »

Hi Daniel,
To answer your questions:
1 - The 'Snap' of the cursor - It is the position of the cursor when you left-click to pick the point - Hence... 'snap' of the button
2 - Yes - I always accept the 'Global Shift'. The original points are UTM so Global Shift is a 'must'.

I can send you the dataset I'm using - it's just shy of 2 million points. I cut it down to only the necessary data. It was 198 million in its original format. Just let me know where to send it.
daniel
Site Admin
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Joined: Wed Oct 13, 2010 7:34 am
Location: Grenoble, France
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Re: Problems with Point Picking on Point List or Trace Polyline

Post by daniel »

Yes, don't hesitate to send it to admin[at]cloudcompare.org
Daniel, CloudCompare admin
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