No Gaze Output When running C++ Samples on Tobii Tracker Bar

[Zhenyi He]

Hi, I want to capture the coordinates of my gaze via tobii tracker bar so I downloaded and followed C++ sample https://developer.tobii.com/consumer-eye-trackers-interaction-library-getting-started/.

I used to get things working around two months ago. However, it is not working now with the same code.

To troubleshoot it, I run the sample cpp_sample.exe in tobii_interaction_lib_windows_x64_0.7.340_beta\bin\x64 and got no results too.

I am sure my device is fine because I can see the trace and also unity sdk is working. I wonder what might be the issue for c++ sdk. I cannot use unity SDK for my project because I want to capture gaze on webpage. Thanks a lot.

[Grant [Tobii]]

Hi @snowymo, could you kindly provide more details with respect to the issue. What exactly happens when you run the stream engine application? Which model of eye tracker are you using? Also, the version number of your IDE and system would be useful. Might also be an idea to test using the older Core SDK to see if the issue truly lies with the Stream Engine API.

Something to also bear in mind is that if you are intending on developing an application for any use other than interaction (or gaming) which appears to be your intention to track gaze on a webpage, then you are legally required to purchase an analytical use licence from Tobii.

Further information about this @ https://developer.tobii.com/license-agreement/

[Zhenyi He]

Hi @Grant [Tobii], Thanks for your fast reply. Let me share my developing information and concerns of license.

=== developing ===
SDK: tobii_interaction_lib_windows_x64_0.7.340_beta
Code: https://tobiitech.github.io/interaction-library-docs/sdk/html/sample_cpp.html
IDE: VS2017
OS: Windows
Device: Tobii Eye Tracker 4C

I downloaded the SDK (tobii_interaction_lib_windows_x64_0.7.340_beta) and used the sample code online https://tobiitech.github.io/interaction-library-docs/sdk/html/sample_cpp.html. The only thing I changed is the resolution code.
I am using vs2017 for developing. I configured include, lib, and dll to associate with SDK folder.
Then I hit run and there is no output. I added breakpoint but the code never went to the callback

intlib->SubscribeGazeFocusEvents([](IL::GazeFocusEvent evt, void* context)
{
// never went into this block
Focus& focus = *static_cast<Focus*>(context);
std::cout
<< “Interactor: ” << evt.id
<< “, focused: ” << std::boolalpha << evt.hasFocus
<< “, timestamp: ” << evt.timestamp_us << ” us”
<< “\n”;
}, &focus);

=== license ===
I am currently using Tobii as the ground truth of gaze information.
I wonder if I used the gaze information to build a game only for research. I should use the “Research development license”. What should I do next?

Thanks.

[Grant [Tobii]]

Hi @snowymo, thanks for your patience whilst we investigated this issue. So long as the code is unaltered as you said, it should be able to run without any issue.

As you mentioned, the Unity SDK is working fine, how about the c# sample for the interaction library? What exactly is the output you receive from the c++ code?

Regarding the licence, if you are developing only a game for interaction purposes then no special action is required, but you mentioned you wish to track for a web page which is now being used for analysis which changes the situation.. could you kindly clarify more precisely the project intentions? Many thanks

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