2 Positions with SL3 Extended View

[Ralf]

Hi Guys,
I tried my first scan with a small reference object in Stereo SL3.
The Calibration Info is in picture one.
I've done 2 Scannes, one in "Extended View" an the other without "Exetended View".
Nothing else has changed.
Picture 2 "firstsacan": you can see the scans in Shape Fusion.
Brown and Blue are the scan in Extended View which are like two scanns and not Fused automaticliy and had not the same position.
The green plane is otpcal exact between the other ones, which is the second scan without Extended View.

Is there someting wrong with calibration, or is there a buttom which i have overlooked?

I thougt the scans from the Extended View will be as "one scan" which don't need to be fused.

Thanks a lot for helping me!
Regards
Ralf

[avogra]

There was some error in the first David 5 Versions, they just released an update. See http://forum.david-3d.com/viewtopic.php?f=16&t=6770&start=90. For stereo scanning (not in extended view), you can reduce the angle between cameras and Projector below 20°. I had good results with 15°. I think with both cameras at 25°some details are difficult to see from both cameras and the projector at the same time. Depends on the object of course.

[Ralf]

Hi avogra,
thanks for your feedback.
We have installed the current Version of David.
The only reason because we bought the second camera with SL3 is, to have "Extended view". And our Scanparts are like scissors (medical instruments), which are thin and have sharp corners and tips.
So we had much problems with the allignment.
The end result after many hours of testing is very good. But the most time is needed for the allignment.
I've calibrated the 60mm glas paddern and the scanparts are about 200mm in front of the Beamer. To focus the position with the cameras the angel has to be in the angle of about 25°.
I want to try to turn the Beamer 90 degrees, but I don't know if the calibration is still working then. If so I could have the camera nearer to the beamer an the angle can bit fit to about 15 to 22 degrees perhaps.
This is because the parts are Small an we need precise scans. A bigger distance to the beamer and cameras we don't have that quality and more problems with the allignment. Thats for sure.
Have A nice Weekend.
Regards
Ralf

[drndadoo]

Calibration should work IMHO, it is like you put the camera above the projector (and under). Thin edges can be a nightmare.

[Curiousjeff]

Hi Ralf,

I thought that "Extended view" (each camera takes an unique separate scan) had a single coordinate system for both scans, thus avoiding alignment and placing both scans perfectly immediately.

David team, can you please explain how "extended view" works ?

Jeff

[Ralf]

Hi guys,
@ Dr. :
No, this is the default formation.
Red Rail, Beamer on default holder, cameras in position left an right.
And like seen in the Calibration info the Software says "calibration successful"
As you see in the first picture, the scan with Extended View brings two different scans to the fuison list, which have diffenrent colours (brown and blue) like scans which are made separately with one camera.
And as seen the surface which both scans have together are not at the same coordiantes.
The reference body which is used has no thin corners.

@Jeff
Yes Jeff you are right, that is my oppinion too. If the cameras have not the same position, and will not have the scan as one result, it will be unsuitable for us, because this will be harder to align as a scan which is made separately beause the surfaces are not overlappung enough. And it has to use the alignment function, as are the postions now.

@David team
Our need is to scan two surfaces in which each camera only can see one of the faces e.g. of a cube. But the scan has the faces in the right position, which need not be aligned.
Because to scan this situation with one camera the alignment will not fit because you have no overlapping.

I need support very quick, beacause we have moved the deadline of some scans to a later time, beacause we thought not to have the appended problems which we have now, and we could save time to have "extended view".


Regards
Ralf

[Ralf]

Sorry for this mistake:
@Jeff
.. . If the "cameras = scans" have not the same position,....