"flickering" pointcloud and visualization problem with vtk

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"flickering" pointcloud and visualization problem with vtk

MungoMan
Hi,
i just created my first scans using a hokuyo lx30 and a flir ptu.
The result looks pretty good... but when I´m trying to work with I have some strange "errors"

loading and downsampling works well... just had to treat the small values i got in the right way...

but at the point when I try to visualize with vtk the problems starts..
1. i really have to search for some points
2. when i find them ^^ they are only viewable in a specific angle... if i rotate the cloud too much it disappears...

I created the pcd.file by hand using the default header

for example:
______________________________________________________________________________________
# .PCD v.7 - Point Cloud Data file format
VERSION .7
FIELDS x y z
SIZE 4 4 4
TYPE F F F
COUNT 1 1 1
WIDTH 155664
HEIGHT 1
VIEWPOINT 0 0 0 1 0 0 0
POINTS 155664
DATA ascii
0.264931530525206 0.0483551020706914 -0.26930824674097
0.257215487215779 0.0469467756964408 -0.259192921015527
0.266548163362522 0.0486501686703682 -0.266263382629533
0.260118935793492 0.0474767109293442 -0.257582806464995
0.259148916267942 0.0472996637010451 -0.254391493088012
0.263014275174078 0.0480051660777366 -0.255940867325664
0.262716649283319 0.047950843625826 -0.253427417027876
0.263102219827473 0.0480212176691913 -0.25159062926046
0.27261090760702 0.0497567361528797 -0.258413441117431
0.267368408042566 0.0487998791074303 -0.251235822809556
0.269860859495112 0.0492547994566812 -0.251367059669499
0.268092772454486 0.0489320895506544 -0.247541295315303
0.274864230725056 0.0501680109798316 -0.251577425242344
0.271641097903907 0.0495797272212127 -0.246454249428043
0.274135422920172 0.0500349895318929 -0.246541248408395
0.275913352798945 0.0503594959452751 -0.245966895867409
0.276966514139479 0.050551718154604 -0.244740770580443
0.274375470467754 0.0500788028282647 -0.24032268230317
0.271021325030882 0.0494666067463625 -0.235298072197752
0.274961662501549 0.0501857941538007 -0.236617668326281
_____________________________________________________________________________________

Does somebody can give me hint why this error or strange behaviour occurs?
Best regards chris
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Re: "flickering" pointcloud and visualization problem with vtk

aichim
Administrator
Hi,

How did you treat the small values in the right way?
The point should be visible from any angle as long as you have them in view.

Press 'h' when you run pcl_viewer and you will get a list of options for navigating inside the point cloud scene. The most useful are 'r' for resetting the camera such that all the points are in view, and 'f' + cursor above a point to navigate closer to that specific point.

Cheers,
Alex
---
http://www.openperception.org



On Feb 27, 2013, at 8:03 AM, MungoMan <[hidden email]> wrote:

> Hi,
> i just created my first scans using a hokuyo lx30 and a flir ptu.
> The result looks pretty good... but when I´m trying to work with I have some
> strange "errors"
>
> loading and downsampling works well... just had to treat the small values i
> got in the right way...
>
> but at the point when I try to visualize with vtk the problems starts..
> 1. i really have to search for some points
> 2. when i find them ^^ they are only viewable in a specific angle... if i
> rotate the cloud too much it disappears...
>
> I created the pcd.file by hand using the default header
>
> for example:
> ______________________________________________________________________________________
> # .PCD v.7 - Point Cloud Data file format
> VERSION .7
> FIELDS x y z
> SIZE 4 4 4
> TYPE F F F
> COUNT 1 1 1
> WIDTH 155664
> HEIGHT 1
> VIEWPOINT 0 0 0 1 0 0 0
> POINTS 155664
> DATA ascii
> 0.264931530525206 0.0483551020706914 -0.26930824674097
> 0.257215487215779 0.0469467756964408 -0.259192921015527
> 0.266548163362522 0.0486501686703682 -0.266263382629533
> 0.260118935793492 0.0474767109293442 -0.257582806464995
> 0.259148916267942 0.0472996637010451 -0.254391493088012
> 0.263014275174078 0.0480051660777366 -0.255940867325664
> 0.262716649283319 0.047950843625826 -0.253427417027876
> 0.263102219827473 0.0480212176691913 -0.25159062926046
> 0.27261090760702 0.0497567361528797 -0.258413441117431
> 0.267368408042566 0.0487998791074303 -0.251235822809556
> 0.269860859495112 0.0492547994566812 -0.251367059669499
> 0.268092772454486 0.0489320895506544 -0.247541295315303
> 0.274864230725056 0.0501680109798316 -0.251577425242344
> 0.271641097903907 0.0495797272212127 -0.246454249428043
> 0.274135422920172 0.0500349895318929 -0.246541248408395
> 0.275913352798945 0.0503594959452751 -0.245966895867409
> 0.276966514139479 0.050551718154604 -0.244740770580443
> 0.274375470467754 0.0500788028282647 -0.24032268230317
> 0.271021325030882 0.0494666067463625 -0.235298072197752
> 0.274961662501549 0.0501857941538007 -0.236617668326281
> _____________________________________________________________________________________
>
> Does somebody can give me hint why this error or strange behaviour occurs?
> Best regards chris
>
>
>
> --
> View this message in context: http://www.pcl-users.org/flickering-pointcloud-and-visualization-problem-with-vtk-tp4026423.html
> Sent from the Point Cloud Library (PCL) Users mailing list mailing list archive at Nabble.com.
> _______________________________________________
> [hidden email] / http://pointclouds.org
> http://pointclouds.org/mailman/listinfo/pcl-users

_______________________________________________
[hidden email] / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users
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Re: "flickering" pointcloud and visualization problem with vtk

MungoMan
Hello Alex,
Thank your for your quick reply. I solved the Problem by onverting the values from m to mm.

Made the handling in viewer possible.
One last last problem I´ve to handle ist the correcet loading of the pcd file...

The created pcd.file seems right but in the visualizer i miss  the half room ;)
Or some areas where a solid wall should be are represented by a bunch of unorganised points...
I attached a foto of the room... all for walls are visible during the process of recording.

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Re: "flickering" pointcloud and visualization problem with vtk

aichim
Administrator
Hi,

Switching to mm might cause problems with the far clipping plane of the visualizer (I cannot check right now what it is by default). Either stay in meters or modify the far clipping plane for the visualizer manually.

Cheers,
Alex

On Feb 28, 2013, at 1:40 AM, MungoMan <[hidden email]> wrote:

> Hello Alex,
> Thank your for your quick reply. I solved the Problem by onverting the
> values from m to mm.
>
> Made the handling in viewer possible.
> One last last problem I´ve to handle ist the correcet loading of the pcd
> file...
>
> The created pcd.file seems right but in the visualizer i miss  the half room
> ;)
> Or some areas where a solid wall should be are represented by a bunch of
> unorganised points...
> I attached a foto of the room... all for walls are visible during the
> process of recording.
>
> <http://www.pcl-users.org/file/n4026463/scan_labor.png>
>
>
>
> --
> View this message in context: http://www.pcl-users.org/flickering-pointcloud-and-visualization-problem-with-vtk-tp4026423p4026463.html
> Sent from the Point Cloud Library (PCL) Users mailing list mailing list archive at Nabble.com.
> _______________________________________________
> [hidden email] / http://pointclouds.org
> http://pointclouds.org/mailman/listinfo/pcl-users
_______________________________________________
[hidden email] / http://pointclouds.org
http://pointclouds.org/mailman/listinfo/pcl-users
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Re: "flickering" pointcloud and visualization problem with vtk

MungoMan
Hm ok... i fixed my problem by sorting out some malicious points.
These had values 1.000.000+ the estimated biggest value sould be 6000 in this room.
so... after deleting these points: