OSC / FLOSC crashes after failing to de-register touch points (?)
Posted: 18 October 2008 01:07 PM   [ Ignore ]
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formula-d-frog-screen.jpg

Hi -

we have a sticky problem with OSC / FLOSC and our FTIR screen. OSC and sometimes FLOSC crashes after failing to de-register touch points in our Adobe Flash application. Our 100” vertical rear-projected screen is installed in a museum environment with many, many kids. It runs stable under “normal” use conditions of 1 to 3 adult users. A typical situation that seems to initialize the above problem is when multiple kids with greasy fingers interact with the screen. First, the grease spots remain registered as touch points on the screen. After that no registered touch seems to de-register anymore resulting in a screen full of “circles” indication the touch points. Finally the flash application freezes or OSC or FLOSC crashes. We theorize over possible solutions such as only allowing a maximum number of touch inputs in Flosc, but we only have the competence to handle the flash side. Has anybody experienced a similar problem and has some advice on this. Much appreciated.

Some notes regarding our setup:
- 2000 mm x 1500 mm x 8 mm acrylic with FTIR
- 3 mm rear projection material
- 570 TV-line CCD B/W camera with IF filter
- Touchlib Beta 2.0 precompiled

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Micha Wolf, Cape Town
http://www.interactiondesign.co.za

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Posted: 20 October 2008 05:32 AM   [ Ignore ]   [ # 1 ]
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Hi, here’s an update on our “grease spot” problem. After a lot of testing last night, it seems that osc/flosc are actually working fine delivering the touch coordinates even when flash is bugging out/registering touch points but not de-registereing them (see photo attached). Also, only the circles/touch markers are being rendered in flash, but the actual touch command doesn’t come through anymore from flosc. Our conclusion at this stage is that we’re dealing with a performance problem. Our flash application, which is based on the Touchlib AS3 package/TUIO, seems not to be able to handle 30-50 simoultaneous touch inputs. On my wish list for the next touchlib release would be that you can limit the amount of touch inputs in osc or flosc. We should be able to eliminate “false” input, e.g. grease spots. We would also love to make flosk aware of osc crashing or not working properly. Right now, if osc gives up, we don’t pick it up in flash, because flosc doesn’t pick it up either.

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Micha Wolf, Cape Town
http://www.interactiondesign.co.za

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Posted: 17 November 2008 01:42 PM   [ Ignore ]   [ # 2 ]
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Hi,

We are also developing Flash applications for multitouch tables. We are having the same problem here in our apps, just as you described. We also debugged and tested many things and, just as you said, it doesn´t seem a OSC or FLOSC issue (it´s easy to see the blob detection at the OSC DOS window). I believe we need the NUI Group help at this problem, since it´s kinda hard to change all the AS3 code at TUIO.as or any other grin… anyway, if we have any progress on this issue, I will post at this topic, ok?

Luiz Daniel Lima, Sandbox Midias Interativas, Fpolis, Brazil

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