CloudCompare forum

For many reasons, it would be really nice to be able to view a point cloud from station coordinates. We can imagine just to be able place the camera at the station, else within the camera properties or directly right click in the object list, if the coordinates of the station can be associated to a point cloud.

This feature would be really nice in order to have a point cloud without holes.

Would it be possible?

Thanks in advance daniel and other guys.

Hello,

I agree, a simple way to do this would be very convenient.

For the moment, you can:
- create a 'sensor' object (Edit > Sensors > Create) if by any chance you know all the necessary information (position, orientation, angular resolution, etc.). If your cloud is a scan corresponding to a single station, and no transformation has been made, you can leave almost all parameters to their default (appart from the angular resolution, and of course the scanner type).
- CloudCompare automatically creates a '2D' view of this station (what we call a 'depth buffer')
- You may have to shrink the db tree and reopen it to see the 'Sensor' object appear (I need to correct this bug ;)
- Once selected, you can ask again for this '2D' view (Edit > Sensors > Ground based lidar > Show depth buffer) or export it to ASCII (Export depth buffer).

I'm interested by the way by any description of either:
- sensor that are not of the 2 actual types (what I call 'theta-phi' - like the Mensi GS - or 'phi - theta' - like the old Mensi Soisic - in fact it's only the rotations order)
- manufacturer proprietary format ;)

Daniel

Hum, thank you for the trick, it's a great think. For sure it's not user friendly for now, but it's almost here.

I'll try to look for your two questions.

I keep in touch on thoose two points.

JF

Hello,

Since you made the improvment for locations of the pivot point for the camera, i just wonder if it might be possible to do the same for the central point of the camera in order to be able as a viewer based camera, to see the scans in a bubble view (sphere or cylinder projection).

In fact many people asked me to be able to do this for exemple for:
-station based segmentation of fiont cloud
-visualization without holes
-etc.

JF

Hello JF,

the new version of CC (27 Jan. 2011) now includes this 'bubble view' feature (see attached image):
- open your cloud
- enable the 'viewer based perspective' mode (F4)
- open the camera parameters dialog
- the 'pivot' point in this particular mode is now the camera position
- you generally also have to set the camera orientation properly (generally 'psi'=-90° and 'phi' = 0° for a point cloud directly output by the scanner)
- eventually you can play with the f.o.v. (field of view) parameter

Give me some feedback,

Daniel

Hello Daniel, it works quite well, thanks a lot.

The problem is that when you want to do a segmentation for example, the camera comes back automatically to a centered perspective, but it's maybe another stuff to segment with this viewer based perspective....

Anyway, thanks for adding this functionnality.

See you,

JF

Ah ! Indeed, interactive segmentation is limited to 'ortho' view right now in CloudCompare.

I don't remember why actually, I'll take a look asap!

Ok, it works now in the last online version (23 Feb. 2011) !

ok thanks for feedback.