DAVID 5 Beta

[robssm]

With david 5, I noticed it is VERY sensitive to the calibration...

I used 2 flat pieces of glass, used plasticoat white on the back of the panels, used v-blocks to properly set the right angle for the target, put the target on a thicker piece of glass to ensure flatness, used vinyl cut decal calibration dots, then sprayed the front with matte clear...

It worked amazing.. The ability of david 5 was absolutely incredible compared to before. Absolutely incredible. .

I need to buy, like yesterday..

[drndadoo]

We are still waiting to see your calibration panels and scan results. It would be great if you can share some pics.

[micr0]

I got a chance to experiment with David 5 yesterday trying to improve calibration and ultimately alignment/distortion. I tried mounting the camera above the projector. Before that I was able to measure my panels with a Romer portable CMM we have at the shop. The Romer returned an angle measurement of dead on 90.00 degrees. FWIW I made these panels. They are 6.35mm glass that are mounted in holders that I machined from aluminum on a CNC mill. With the camera above the projector my results were better (maybe) but still not acceptable. The PC I am using to scan is not net connected and I forgot to copy my screen grabs to a flash drive. Over a distance of about 250mm I got a deviation of ~2.5mm. With David 4 and the same set up the deviation was ~.3mm over the same distance. I'll have more time in a few days to try a few things like swapping the camera and or projector and take some screen grabs. I'll post then.

[micr0]

One thing I just realized might be important. I'm using a positive (convex, outside) calibration corner.

[avogra]

Finally, I found time to do some scans. I tried the new sequence features, actually the "manual scan sequence" with "auto next scan" and "motion detection" enabled.
Some comments:

a) I think in the advanced options [Structured Light]->[Acquisition]->[Movement Detection], there is something mixed up with the Options [Rest Duration] and [AutoNextScanDelay]. When you enable the [Auto. Next Scan] Checkbox, there is this red bar filling up which is being reset as long as there is motion in the scene. The time, this bar takes to fill is determined by [AutoNextScanDelay], not [Rest Duration] which I would have expected from the option's description. And an extra question: how are those two parameters meant to play together? Is it like, first wait that there is no more movement for [Rest Duration] and after that, wait another [AutoNextScanDelay]?

b) I think the sensitivity of the motion detection should be adjustable. My first scan was a small tree which swayed many seconds after I turned it for the next scan. It was still moving when David already started the next scan.

c) The movement detection bar starts just after the last scan has finished. Wouldn't it be possible to first check if it has already moved since the last rest position and only start if image content is different? Like I have all the time I want to start moving my object and if I have started to move it, David will start to wait for the new stable position?

[Sven]

Hi all,

Thank you for your reports. We have done a lot of tests, and indeed, in some setups the calibration can be somewhat off, so that scans of left and right camera don't fit together (Extended View mode only).

We have improved calibration for two cameras. It is now much more robust especially when the calibration corner is not built precisely, or when the camera view direction is not ideal.
For those who have seen that problem, please try our new beta version: http://downloads.david-3d.com/software/ ... _beta1.zip
The relevant new setting is at Advanced Settings -> Calibration -> OptimizeMultiCameraCalibration (on by default)

Thanks
Sven

[hal]

Thanks Sven, I will try it
Mattia

[micr0]

It is a true beta

I finally got a chance to try it and could not calibrate. It would run through all the cal patterns and the three colors for white balance then process for a second or two then this:

(insert picture of crash screen here)

Admins. I tried to upload a picture and the board returned a "Sorry, The board attachment quota has been reached" Error.

[Sven]

Hi micr0,
Our forum has now reached the limit of 2000 MB for attachments, set many years ago...
I have increased it to 4000 MB.
Please post your error message / screen shot and some basic info about your hardware setup.Thanks!
Sven

[micr0]

[Sven]

Thanks Micr0,
The Console Window SHOULD be open during the "crash" message, but hidden behind the main window? You could try to have them next to each other, so you can make a screen shot before you close the "crash" message.
Sven

[micr0]

[micr0]

I was able to get it to successfully calibrate finally. I first got it to stop crashing by increasing the projector/camera angle to over 25deg. At >25 I it would hang at the projector calibration and then give me a failed to calibrate dialog. but it wasn't crashing. Then I increased the projector/camera angle to >30deg and it did calibrate. However it still took a very long time at the Projector calibration phase. Scanning too seems to have a bit of trouble too. About 2/3 of the way through the scan it hangs for a few seconds before continuing. Right now scans on default setting are taking about 33seconds where as David 4 does them in just about 3.

Ill post screenshots when I get the chance to pull then off the other machine.

[Sven]

Hi,

We have just released version 5.0.4, mainly because of the .

In all our tests the calibration works fine, and more precise than in the previous release.
However, @Micr0 (and others): We are still interested in your problem reports. I hope we can reproduce and understand why it doesn't work well on your system. Please post more info when you have it.

Thanks
Sven

[micr0]

I got some time today to work with the David 5 beta. I got mixed results. I am going to have a very careful look at my calibration procedure just to rule out anything there. i wish i could offer more technical detail as to what is happening here but I haven't spent enough time to figure anything out.

After getting a successful calibration (camera and projector at 29deg) Here is a set of scans I did. This is 12 scans (rotated 30degrees) of the transmission cases I've been using for test purposes.

The surfaces appear to be aligning very well....

Fused:

However when you rotate the model...

This is how it looks on the other side. When I aligned to correct this the other side was now way out of alignment.

Like I said, I want to make sure this is not caused by my error. However I have been using David 4 with the same set up and haven't had these problems.