DAVID 5 Beta

[hal]

Hello dear David team and dear Sven,
I've tried a little the new r.5 and it seems promising: I like it!

After the first try, I've found something I don't understand: I have a dual camera setup with a David camera working at 25 fps and an TheImagingSource usb3 working at 60 fps.
By default David 5 read both, but the 60 fps one works at 15 fps (its exposure value moved automatically to 1/15). If I try to set it at 60, the camera stop to work after few seconds. Both cameras have their onw latest drivers installed.

Is taht an issue or a feautre needed to works correctly with these cameras togheter? In the online manual it is wrote that could be related to USB connection bandwidth... so setting a fps limit could solve? I ask that because I still don't understand why the faster camera is moved to 15 fps instead 30 or 25, like the other camera. And why David set it like that every time I run the software?

Thanks,
Mattia

p.s.: the new SL patterns have alterned bigger lines, right? at the first try, I thought my projector has a wrong resolution ratio, because similar effect happened time ago, when the resolution of the projector was wrong and some lines were "fused" together

[Sven]

Hi Mattia,
Your problem sounds like a USB bandwidth problem.
DAVID allows you to set frate rate and exposure time for both cameras as you like.
The exposure should not change automatically to 1/15, and you should be able to change it as you like.
Here it works fine with two different DAVID cams. I'll try it with 1 DAVID and 1 ImagingSource camera when I have time.

Please try the "Frame Rate Limit" switch in DAVID5.
Also you could try to use different USB ports.

PS: Our new patterns are indeed different. There are no more black and white stripes, only sine waves. In some patterns, there seems to be "errors" / "steps" in the sine waves, but those are deliberate

[Sven]

Hello,

We have just released DAVID 5.0.3, which includes bug fixes about calibration and white balancing, and textures in Shapefusion. Please use AutoUpdate or Download to update.
The fixed calibration issue relates to the distortions that some of you have seen. Also "calibration failed" when using a "negative corner" set-up had a bug.

However the problems "calibration failed" that some of you had with very dark images or bad view on the calibration panel etc. I'm afraid need to be solved on your side, by improving the set-up.
We will keep looking and testing calibration, if there is a bug in DAVID5 we will fix it.

If your calibration fails and you think your set-up is good, please post a screen shot, that will help us reproduce the problem. Thanks!

Sven

[hal]

Thanks dear Sven,
I plan to test the 5.0.3 release tomorrow.
In meantime I will try different usb ports and configurations. But thanks to confirm that it is bandwidth problem: that solved my doubts.
Hope soon to share more opinions on your latest "baby".
Have nice afternoon,
Mattia

[micr0]

I tried a number of different exposure settings (Using both the camera aperture and the projector brightness, to the point of over and under exposure), I tried different camera angles relative to the projector. I tried different angles of the camera and projector relative to the calibration panels. I tried different distances to the calibration panels for both the camera and the projector. After 1.5hr I ran out of time and never got a successful calibration with David 5. David 4 almost never failed to calibrate. David 4 may be more tolerant but I starting to wonder if there may be some other problem. Perhaps something didn't install correctly or a missing software component or incompatibility?

[Sven]

@micr0:
whoops yes there seems to be some other problem...
Does the CAMERA calibration fail (at the beginning, before the stripe pattern sequence is projected) or does the PROJECTOR calibration fail (after the stripe pattern sequence)?

[micr0]

@micr0:
whoops yes there seems to be some other problem...
Does the CAMERA calibration fail (at the beginning, before the stripe pattern sequence is projected) or does the PROJECTOR calibration fail (after the stripe pattern sequence)?

It fails after the stripe sequence.

[Sven]

I just see, micr0, you are using a negative corner, right? There indeed was a bug in DAVID5, please try again with 5.0.3.

[micr0]

I just see, micr0, you are using a negative corner, right? There indeed was a bug in DAVID5, please try again with 5.0.3.

Ok, Thanks.

I"m not at the shop till Friday so I'll report back after I can get time to try it out.

[hunkatibor2]

Hi Sven


Tibor

[Sven]

Hi Mattia,

Fortunately I also have an ImagingSource camera, so I could do a quick test. I have connected it together with one DAVID camera.
It works fine. I get full frame rate from both cameras and I can change the Exposure Time separately, with no crashes. (If you haven't seen: you can set format and properties of each camera when moving your mouse over the little preview images at the right side, there are the buttons).

PS: When you get it working and do stereo tests: You have two DIFFERENT cameras, that's not recommended but it will work of course. There is a difference in the algorithm which camera is "first" and "second". Try to connect camera A first, then B, and do stereo scans. Then connect camera B first and then A, and scan again. The scan result will be different. To be honest I haven't tested that constellation much yet.
(In "Extended View" the result should be identical because there both cameras make separate scans.)

Sven

[hal]

Dear Sven, thanks to check it.

I've tried and you are right. I've found also a problem here with the USB devices: seems there is something going wrong and avery time the crash happen in different conditions. But 1 time on 10 everything works for some time. So the issue is fully related to my USB system here that working bad. I will try on different computer soon. Also one camera is the usb2, the other is an usb3.

When I was able to scan without camera crashes, I've done a first tests. Angle between cameras at 34°, first cam at 19° with projector, second cam at 15° with projector.

Extended mode

Here we can see that in Extended mode the 2 different scans appear. They shouldn't be overlapped? That result means my calibration isn't enough strong?

Stereo Mode in YELLOW

Here is visible that the yellow scan, took via Stereo mode, is placed in the middle. That sounds like an average scan between camera A and camera B

This make me confused... I thought that in Extended mode I should scan more surface of my object and loose little precision, and with Stereo mode I can scan only the surfaces saw from both camera in order to get best precision. But these 3 different scan positions in the XYZ space are talking to me that is something wrong in my process.
That is related to the differences between cameras? or their optics? or the low calibration angle?

Thanks and best regards,
Mattia

[avogra]

I tried the new stereo mode with two Logitech cams and I'm very impressed. With David 4 I had to clean edges on most scans which is now completely gone. I also like all those small changes like the merge of setup and calibration, ability to dictate the names of the scans. I didn't try it yet, but scan sequence looks very handy. Great job!!
One thing I'm missing: the texturing tab has vanished with no mention in the release notes. So is there no more manual texturing or is it yet to come? My first test gave me quite mediocre textures which were too dark and tinted. It also did texturing by projecting a sequence of R G and B. Having a colour cam, David 4 just projected a white image. Will this be possible again?
Some more questions about stereo mode:
For small objects, I have trouble to get the right cam close enough to the projector. In my setup, the body of projector and cam are in between the lens of the projector and the lens of the cam. Due to the reduced angle the cam would have to come even closer than before.
What I thought about: Does it make any sense to have one cam to the left and the second cam above the projector or is this total nonsense?

Cheers, Alex

[Sven]

Hi Mattia,

This make me confused... I thought that in Extended mode I should scan more surface of my object and loose little precision, and with Stereo mode I can scan only the surfaces saw from both camera in order to get best precision. But these 3 different scan positions in the XYZ space are talking to me that is something wrong in my process.
That is related to the differences between cameras? or their optics? or the low calibration angle?

I assume that your PROJECTOR calibration was not precise. What model do you have? Maybe there is some temperature drift? Please let it run warm before calibration-
Please try the same with "Quality" mode. There the scans should overlap very well.

Please keep in mind that hardware is never perfect, so when you zoom in more and more, eventually you will see differences. Both those differences should not be more than the accuracy we have (something around 0.1% of scan size, depending on hardware). Did you measure the distance, how much is it?

Sven

[Sven]

Hi Alex,

Thanks for your good questions and ideas!

I tried the new stereo mode with two Logitech cams and I'm very impressed. With David 4 I had to clean edges on most scans which is now completely gone. I also like all those small changes like the merge of setup and calibration, ability to dictate the names of the scans. I didn't try it yet, but scan sequence looks very handy. Great job!!

Thanks

One thing I'm missing: the texturing tab has vanished with no mention in the release notes. So is there no more manual texturing or is it yet to come?

Textures are taken automatically during the scan with "Auto Grab Texture" option. That is the fastest and most comfortable solution, and it makes sure that the texture fits perfectly on the scan.
In your application, why do you need to grab the texture separately?

My first test gave me quite mediocre textures which were too dark and tinted.

That must have been before version 5.0.3, where we had to fix a bug related to that. So please try 5.0.3.
Otherwise did you maybe change camera settings or exposure after calibration?
If not, then there may still be a bug in DAVID5. In that case please try to reproduce the problem and let me know.

It also did texturing by projecting a sequence of R G and B. Having a colour cam, David 4 just projected a white image. Will this be possible again?

Yes, sorry. We are working on it.

Some more questions about stereo mode: For small objects, I have trouble to get the right cam close enough to the projector. In my setup, the body of projector and cam are in between the lens of the projector and the lens of the cam. Due to the reduced angle the cam would have to come even closer than before.

In that case, you should use a larger camera angle.

What I thought about: Does it make any sense to have one cam to the left and the second cam above the projector or is this total nonsense?

Interesting idea! Please give it a try. You must then use pattern orientation "both".
Another option could be to place one camera at the top left of the projector, and the other camera at the top right of the projector. So both cameras would be diagonal above the projector. I'd say that is promising!

Sven