TouchCore and Cameras FAQ

Table of contents


Calibration

Q: How does the calibration work with more than one camera?
A: The Snowflake TouchCore calibration supports any number of cameras. The camera settings are set individually for each camera, whereas the white balance and point calibration steps are done for all cameras at the same time. Please look at TouchCore Calibration for more details.

Q: Do you have a dynamic background subtraction? Or what kind of substations are possible?
A: Dynamic background subtraction is indeed part of TouchCore.

Q: I can't get any input at all, what can I do?
A: Go to C:\Documents and Settings\{username}\Application Data\Natural User Interface Technologies AB\ and delete the folder called Calibration and then redo the calibration from the beginning. Please look at TouchCore Calibration for more details.

Q: I'm running the TouchCore calibration in an adjusted render area (as set in step 1). My inputs appears offset when sent via TUIO to Flash (or another 3rd party application).
A: Open and edit the file <INSTALL_PATH>/bin/Config.cfg in Notepad. Look for the variable called RenderInputMarkersGlobally, set it to True. Now perform the calibration again. Please note that your inputs will now appear wrongly in Snowflake, but they will be sent correctly via TUIO.

Tracker

Q: How many cameras can I use with your tracker?
A: Snowflake Suite has multiple camera support. We have mostly tested one to four camera setups, through our partners in real life scenarios.

Q: How many FPS (frames per second) can the tracker handle with one or two cameras?
A: The tracker itself can handle anything, it depends on the performance of the computer and the camera(s).

Misc

Q: Which protocol do you use to send the events?
A: We use OSC messages in the TUIO (2DCur) format for sending input events from TouchCore to any client application (Flash, Java, C#, Python, etc).

Q: Does Snowflake support only Firewire cameras?
A: Officially yes, currently Snowflake supports any Firewire cameras that are supported by the 1394 CMU Driver. However, we've also got support for the PtGrey Flycapture drivers, which means that any PtGrey camera using these drivers (both Firewire and USB) can be used. Please note that there are some instabilities with these drivers that can cause unexpected crashes during calibration.

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