Trouble with UE 4.7.6

[Eric Chu]

I’m trying to use the plug in on an existing project and tried use the first example in the developer guide but nothing is happening (it is supposed to draw a rectangle where the gaze point is).

I tried using the example project that they provide with the download and that worked, so I’m not sure what the problem is.

Any help is greatly appreciated thanks.

[Jenny [Tobii]]

Hi Eric,

It’s a good sign that the example project works, that means that we should be able to get your existing project working as well.

So, let’s go step by step. Can you confirm that you followed all the steps provided in the README for how to import the plugin to your own game project?

To import the plugin into your own game project:

• Create a new directory in your Unreal project directory called “Plugins”.
• Copy the contents of the Plugins directory in this repository into that directory.
• Start the editor and open the plugin viewer (can be found in the Windows->Plugins menu).
• Add a reference to the module in your build script (MYPROJECT.Build.cs). The relevant row might look something like: PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "TobiiEyeX" });

Second question: Are you using the EyeX function library (Blueprints) or the IEyeXPlugin interface (C++)?

[Eric Chu]

Thanks for the reply Jenny,

I actually realized that I had included the files for the plugin in the engine directory rather than the project directory, so the problem I was having was fixed.

I have another question regarding the accuracy of the eye tracker, because where I’m looking is up and to the left of where it actually reads the input.

Thanks
Eric

[Eric Chu]

I am also having issues with the “EyeXActorBase” class where I cannot rotate of move the mesh.

Also I am using blueprints.

[Jenny [Tobii]]

Hi Eric,

Great news that it worked out!

There can be some offset in the calibration depending on how well the eye tracking algorithms are able to model your eyes. But it could also be due to something else more specific to the EyeX Plugin for UE4.

Go to the EyeX Settings (can be found by right-clicking the EyeX icon in the task bar), and click the Test Eye Tracking button. If the offset is the same in this test app, the problem is with the calibration. It might be improved by re-calibrating, but it might not. If there is no offset in the test app the same way as in Unreal Engine, then there is something specific for UE going on.

We have had a known offset problem in UE4, where you would have to use a workaround and move the mouse over the game window once in order for the EyeX Plugin to be able to update with correct coordinates. I’m not sure if UE4.7 includes a fix for this or not (our pull request was rejected and the UE team went for another solution which I haven’t had the chance to try out yet). So, you could try and see if it helps moving the mouse over the window.

[Eric Chu]

Thanks for the help

The eye tracker is now working properly after I move the mouse over the window.

I have run into another problem where I make a blueprint class based off of the EyeXActorBase class and it won’t rotate or move (haven’t tried anything else with it), but it doesn’t seem to want to do anything.

Thanks again for your help
Eric

[Temaran]

Hello there Eric!

Regarding the accuracy problem, there is actually a bug in our plugin that appears when you use different screen and render resolutions. The plugin will only read the screen resolution, so you can get pretty severe diffs depending on the difference between screen / surface resolution. This problem will only appear in fullscreen modes though, so if you are having the problem in the editor it’s probably just a bad calibration like Jenny said 🙂

I have made a fix to this, I just haven’t had the time to make a pull request yet, but I’ll post the diff below.

When it comes to deriving from the sample actor bases etc. it might not be as easy as simply deriving from it. I haven’t looked at that for a bit, but you might have to hook some stuff up as well to get the expected behavior. I would recommend checking out the code and mirror what is done in the sample.
If you can explain more in detail what you want to make, I might be able to provide you with a BP-sample that works for 4.7!

Link to pull request that fixes fullscreen differing resolution bug and some other stuff:
https://github.com/TobiiTechnology/EyeXforUE4/pull/2

Best regards,
Temaran

[Eric Chu]

Thanks for the help all,

I found that I could fix the problem with what Jenny had said:
“where you would have to use a workaround and move the mouse over the game window once in order for the EyeX Plugin to be able to update with correct coordinates.”

That was the main problem I had, although there are still some gaze point collision hiccups it’s managable.

I have run into another problem though,

When creating an entity that uses the built in functionality for path finding (NavMesh) you make a Class that is a child of the “Character” class. But I also want the character to respond to the EyeX tracker is it possible to implement some of the character components into a class that is a Child of the “EyeXActorBase” class because I cannot attach an AI controller to the “EyeXActorBase” class.

If there is an alternative solution for this please let me know.

Thanks
Eric

[Author]

Posts