Hi,

I have been following this community for some months now, and have gained a wealth of information from all of you with regards to table design and construction. I am posting today to show you the result of several months of work and several thousand $$$. All of which made possible by many of those like yourselves with your ideas, mistteps and advice.

Like many of you, I was inspired by Microsoft Surface and one day decided that I was sick of seeing the videos on YouTube knowing that in Australia I would never actually get to use a unit myself. So I went ahead and embarked on this project - here is the result (see attached image). It is a work-in-progress, but as a basis for future work, it is solid. I am currently running Microsoft Surface Workstation Edition with the recently-released application suites and it works. There are issues which I will list below for those in the CCV/CustomSurfaceInput/MultitouchVista projects who might read this.

Applications in my home:
- Games (sadly, only chess at this time)
- Windows 7 Media Center controller (for connected TV)
- Map viewer
- Photo viewer

Project Cost to Date:
AUD$3,000.

Specifications:
- Acrylic construction. All components fully enclosed in box.
- Dimensions: 915mm x 610mm x 470mm (LxWxD)
- Rear DI (top surface: 10mm clear + 5mm frosted pearl)
- BenQ MP522 ST DLP Short Throw 1024x768 projector
- Integrated PC with GeForce 9500 GT graphics card
- PS3Eye camera (single w/ wide-angle lense)
- 4x IR LED flood lights
- CCV 1.3a
- Windows 7 Ultimate
- Multi Touch Vista, CustomSurfaceInput

Pending Work:
- Investigate use of drafting paper to achieve a sharper image
- Wait for CCV 1.3a to correctly handle movement threshold so I can reduce touch point jitter
- Improve ventilation

Issues with Software:
- CCV will sometimes crash when launched at Startup in Windows 7 with a “glut32.dll” error. Delayed manual start works fine. If no solution posted, will use a wait() loop to execute at startup.
- CCV 1.3a does not handle the “movement threshold” parameter correctly. At any value greater than 0, only gross movements are registered. This problem did not exist with CCV 1.2. I upgraded so that I could use the new camera calibration features of 1.3 (required for my wide-angle lens).
- CustomSurfaceInput/MultiTouchVista will sometimes crash the MS Surface Shell after an extended period of time
- No solution exists (that I could find) to disable Windows 7’s touch feedback and gestures when using your finger in MS Surface Shell

Again, I’d like to thank you, the community for making it possible for me to complete this project. I’ve seen some impressive solutions out there, many of which of greater build quality and/or scale than mine - they continue to be an inspiration for my next attempt. As above, the project cost was approx. $3,000 Australian dollars. This could easily have blown out past $5,000 had I used a high-grade projection surface like Evonik’s Acylite RP. Sadly, I’m not loaded.

Cheers, from Australia.

Update - 07 Dec 09:
Mirror upgrade is complete, as you can see from the new image, the results are simply amazing. The projection area is now a uniform rectangle with sharp edges. Text is now readable across the entire surface. Further sharpening can be achieved through the use of drafting paper, my next improvement. So what are these mirrors?

Front-surface mirrors have their reflective coating on the front of the glass, to eliminate secondary reflections. They are typically used in rear-projection TVs. Mine are 1/8” thick, and are of trapezoidal shape to minimise space wastage inside the box. Cost: AUD$300 for 2 mirrors from http://www.frontsurfacemirrors.net/glass.htm.

Nice work mate
Where abouts in Australia areyuo from? Im in Melbourne
Could you include some photos of the inside.
Tim

Hey mate,

I’m posted to Sydney at the moment, however will be staying in Glen Iris, Melbourne during Xmas.

I remember trying to access your blog a while back - could you add me so I can take a look at your projects?

I’ve updated my original post with images of the interior.

Btw, if any willing Americans are reading this - I’d be interested in acquiring a cut of Acrylite RP through someone in the US via the Evonik USA site. You see, if one of us Aussies were to do that, we’d pay an arm and a left testicle to get it shipped in. And then it’d be an entire sheet of the stuff. If so, PM me so we can discuss how much it would cost you to do it.

Thanks,

Pete

Thanks
I have nothing on my blog for the moment, imay start up a new public one
where did you buy your ir lamps, mine are in desperate need of an upgrade
Tim

Got em from eBay - http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=280313794275.

They’re cheap and do work - however it’s very hard to achieve even and workable illumination across the surface. As you can see from my setup, I am shining them on an oblique angle so as to minimise beam hotspots.

The actual IR blobs are fairly weak, though this can be compensated for in CCV by fine-tuning (esp. amplification and high-pass filter).

I hope to achieve better results when I experiment with drafting paper, as it will reduce the 5mm impedance caused by the frosted pearl acrylic.

Pete

awesome work Peter.

I too have had some trouble with CCV 1.3a and its movement threshold i have mine set to zero for now.

Have you had any trouble with daylight, night-time configuration… for now im having to adjust based on what time of the day im using it.

David

Great work Peter! Looking forward to seeing the table in action!

I’m in Melbourne too and I’ve just placed an order for a 3m x 2m sheet of 6mm Endlighten..

I’ll be posting next week some time with the measurements of the pieces I’ll have left over for sale…

Should make a few Aussies happy

That looks like an interesting mirror arrangement.  I’ve got a similar set up but only have one mirror.  Have I been missing something by just using one mirror and bouncing it straight back up to the surface?

I do get a bit of a hot spot mind you…

Hey Peter! Very nice looking table. SAy, where did you get such a wide lens for the ps3 cam? Custom 12 mount i guess? Does this solution work ok ? Im running 32” “ wide and i am looking for a way of start running apps at my table. Got to cams but not a good way of running them together yet. Maybe i only need one?

Kiwidave - I did experience an issue with UV light from the sun when testing today. Microsoft’s Surface manual recommends installing UV-filtering film on windows that are letting light directly shine onto the table - a bit extreme. The cheap man’s solution would be to close the curtains

Paolo - I did testing with just 1 mirror, however my target was to produce a projection of almost 1000mm in length. This proved to be unsuccessful; despite the fact the projector (BenQ MP522 ST) has a short-throw lens, its physical size made that impossible as it obstructed the image. Also, the proportions became messed up. So I would say yes, it may be feasible to achieve what you want with a single mirror, just bear in mind you may have to trade off projection area.

Limpa - Thanks mate. The lens is from the Peau Productions shop: http://peauproductions.com/store/index.php?main_page=product_info&cPath=4&products_id=1. It’s the 2.1mm 116deg lens. The depth-of-field distortion does not have a significant effect on coordinate transformation once properly calibrated. If using CCV, ensure you have enough calibration points (I use about 5x5 points). Just one point - while I don’t have any screenshots of the raw camera output, I can say for sure that you won’t hope to do any kind of fiducial tracking (using ReacTIVision for instance) as the definition is too poor. Hence the reason why MS Surface uses multiple cameras.

Fairlane - I’m really after the Acrylite RP, according to http://peauproductions.com/reardi.html, the diffuser layer needs something like 7D006. I’m going to see how I go firstly with drafting paper, will post results once I have them. Thanks for your offer anyway

your setup is great. what are the dimensions of box and which projector you use?
thx

Hey, thanks for the quick answer! Just orderd the lens. Its worth a try! Great job man!

Have updated the original post with box dimensions and projector used.

Peter - congrats on the design, impressive.

You mentioned that you experienced an issue with UV light. Could you elaborate?
- Why is UV a problem when you use IR and filter all light except UV?
- Don’t you have a problem with IR light from a direct sunlight?

kolinko - Thanks mate. I’ll outline the issue I have experienced with UV/IR light:

- When the surface is illuminated by sunlight, it increases the ambient IR levels picked up by the camera. This is exacerbated by the fact that I have the camera’s exposure control set to manual (as auto doesn’t yield good results). Therefore, when this occurs CCV has trouble distinguishing fingers from the ambient levels of IR.
- Sunlight as you know contains a very broad spectrum of radiation, not just visible light. Therefore direct sunlight on your table can have a negative effect, as explained above.
- For a good explanation of this, refer to the Environmental Factors section on page 25 of http://www.microsoft.com/downloads/details.aspx?familyid=CACC79C7-42E4-41DB-BD23-4E0D849F56B5&displaylang=en.

So how to address the issue?
- Close curtains to eliminate direct sunlight
- Attempt to use auto-exposure control to mitigate changing levels of IR

Hope this helps,

Peter

Hey!
Just tested my new lens and i am having trouble getting blobs at the edges working fine in the middle. Running on 6 fps right now aswell. Dunno why actually.
Shit! Depressing!