The DAVID 3D scanner is do-it-yourself 3d scanning kit. It uses a line-laser, a webcam and the DAVID software to ‘read’ the depth information of a scene. Once you’ve made multiple scans of an object, it can stitch them together to get a to get a full 360 degree scan.
The cool thing is that you can use the basic DAVID scanning software for free (albeit limited in resolution). The stitching software (‘Shape Fusion’), though, is commercial and is included in the professional version of the software which starts at € 199,-. So if you have a decent webcam and a line-laser (which you can buy starting at € 19,- in the DAVID shop), you can start experimenting with 3D scanning on a *really* tight budget.
  • I was curious to see how well this worked and if the scanned models would work with Shapeways, and requested a DAVID starter kit for review. This kit sells for €399 on their website, and contains everything you need to scan and stitch your objects:
  • Several calibration panels (for different scan sizes).
  • A red line laser, battery operated with adjustable focus.
  • QuickCam Pro9000 1600×1200 webcam including a stand.
  • A USB Stick with software.
  • An extensive manual.
  • Monkey not included 😉

Getting started
Installation was easy enough if you follow the manual step by step. The main things to do are to install the webcam drivers, and install .NET 2.0 if you haven’t already. The software itself runs off the USB key (which functions as copy protection) and requires no installation.
The manual I received was in German by the way but I’m sure that was just a mistake. I *was* a bit disappointed though that only after my tests I found out about their excellent on-line manual that contains much better information than the printed version! (You’ll find the link at the end of this article).

Mac users
I immediately ran into a snag: the DAVID software is Windows-only and I’m a Mac user. Fortunately I can run Windows under VMWare Fusion which did a great job in recognizing the webcam and USB key. The performance was acceptable on a MacBook Pro, although my system wasn’t powerful enough to use the camera at the highest resolution of 1600×1200 pixels at a reasonable speed. Therefore, the resolution of my scan is probably not the optimal result that you can achieve with DAVID.

Calibrating the system
Before you can start scanning, you’ll have to teach the software about the environment you’re using. This is easy as it’s all done automatically during the ‘calibration’ process.  First choose the correct calibration panel; there are three panels for different scan sizes. Use the one that matches the size of the object you want to scan.
Now start the calibration and everything will be taken care of. I did find that during my initial tests the system had trouble to calibrate correctly, but the manual explained how to fix this using some manual corrections on the calibration image.
The system now knows all it needs to know about the lens and the setup to create ‘absolute scale’ models.
After the software is calibrated, do not touch the camera or calibration panels anymore! If you do, you’ll have to start all over.

Tip: If you don’t have calibration panels, you can make them yourself!

Running the scan
Scanning is easy but time consuming: you ‘brush’ over your object with the laser line. At the same time you see the contour lines appear on the screen, and you can keep going until you feel that you’ve scanned in enough points to get an accurate render of your object. 
Once you’re happy with the result you save the scan, rotate the object by 45 or 90 degrees and repeat. 
I found that creating a good scan takes about 5 minutes per step – I’m guessing that on a faster computer this might be a bit less as it would be easier to accurately scan small details.


Stitching the scans
During the stitching phase you align the separate 3D scans. Again, the software is quite clever. Most of the time, you’ll only need to select two scans and watch the software move them about until they match (this is a lot of fun to watch, actually!).  
After alignment, the object still looks messy: it has some outliers and holes in them. This is where the ‘Fuse’ step comes in: it’ll smooth the surface of your object and close all the hole in the surface. And here’s where the REALLY good news comes in: *Fuse creates watertight or manifold objects!* Yes, you can upload these models straight to Shapeways! Awesomeness.

Conclusion

I love it! There you have it. And I’ve seriously considered NOT to return my review unit to DAVID 😉
Having said that: don’t expect a magic wand: scanning your object takes serious time and effort. You’ll be spending a LOT of time in a dark room tweaking the settings and laboriously sweeping a laser-beam over your objects. After a while it’ll get easier though and you’ll get a feeling for how to set everything up. The scanner won’t be able to scan every object to throw at it: highly reflective or transparent objects are difficult, but you can solve that by spraypainting or powdering them.
I also found the software a bit on the technical side and not as user-friendly as it could be. It gets the job done rather well though, so this is not too much of an issue.

Did I feel that the DAVID Starter Kit is good value for money?
Receiving all the required equipment is very convenient (especially for busy people like me), and I especially appreciated the ready-to-use calibration panels. If you want to save yourself some money you can print these out yourself though and buy a cheap webcam and focusing line laser on the web – that would probably shave off about € 100,- of the total kit price. 
The scanned result was impressive enough and I’m sure it could be further improved with more practice and a computer that could actually use the high resolution of the webcam.
Count in Shape Fusion’s ability to generate ready-to-print models for Shapeways and I’d say this is a definitive must-have for designers who are into 3D printing.

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