G2OM overflow

[Nils Ole Block]

Hi, it’s me again. I’m still puzzled on how to use of some features within the TobiiXR library and the SRanipal stuff, so I guess I will have some more questions down the line.

Right now I’m trying to use the eye tracking in a project to test if it can improve the hand selection on a very dense pool of small objects. After using the ray approach I wanted to see what G2OM could do and built a small script to experiment.
Problem is, that: G2OM was initialized with a capacity of 30, but was supplied with 32. Purging overflowing elements.
I again couldn’t find any setting to up that number (like it’s common for instance in SteamVR). And when I finally gave up and “hacked” the value in by myself by overwriting the G2OM_Description options in the G2OM classes constructor I get some error messages including: NotPermittedByLicense

So I’m not quite sure if that just screwed up the underlying system or if this is really a license problem?
By the way, I’m doing all this for research in my Bachelor Thesis.

Greeting,
Nils Ole

[Grant [Tobii]]

Hi @noblauch, thanks for your patience whilst we investigated the issue.

It turns out that your experience is a result of a licence restriction. In order to apply for the appropriate licence, please get in touch directly with the XR team [email protected] and one of our specialists will get back to you promptly.

Thanks for your understanding and best of luck with your project.

[Nils Ole Block]

Thank you,

I wrote them a mail.

[Grant [Tobii]]

Great! Please do get in touch again should we require any further information.

[Jeremy Gordon]

I am seeing this warning as well, and it appears to be correlated with an extreme reduction in performance for our unity experiment (using Vive Pro Eye).
Is this issue always related to a license problem, or is there something else that might be causing it?

[Grant [Tobii]]

Hi @jrgordon, thanks for your feedback. Certainly, this sounds again like a licencing issue but if this is a bug, could you pleaes file an official report @ https://vr.tobii.com/sdk/contact/ and selecting contact type as Feedback

Thereafter, a member of the development team should be able to investigate it and get back to you.

[Jeremy Gordon]

Hi Grant,
If this is a licensing issue, what is the recommended way to resolve it?
Jeremy

[Grant [Tobii]]

Hi @jrgordon, you will need to request to purchase a special licence that permits increasing the G20M threshold using the same form link as provided above. Best Wishes.

[Jeremy Gordon]

Hi Grant. Just to be clear, the “form link” you’re referencing is just this email address ([email protected]), correct?

[Grant [Tobii]]

Hi @jrgordon, I spoke with the developers and I’m afraid that the extended licence file for large number of G20M elements is currently only provided for clients with bulk orders and that for the time being, this is not available for end users. Apologies for the disappointing news, hopefully this does not overly impact your current project.

[Jeremy Gordon]

Hi Grant,
Thanks for the information. In order to assess whether this impacts our ongoing research study, it is quite important that I understand the correct interpretation of this G2OM overflow warning & limitation. Is it documented anywhere? Can you provide details?

For example,
– Is there an upper limit on the number of G2OM objects that can be tracked in a single scene? Or is the limit per frame?
– What is the limit? The warning includes the number 30, does this indicate that 30 is the upper limit of tracked objects for end-users?
– What happens for objects that exceed this limit? Do they simply not generate callbacks on fixation?
– How are objects prioritized? That is, how can I determine which objects have been successfully tracked, and which objects’ events are being ignored?

I appreciate your quick response, if possible. Even today we’re running participants in a study that I’m now worried is affected by this issue.

Thank you,
Jeremy

[Grant [Tobii]]

Hi @jrgordon, apologies for the delay in response. The engineer responsible for the G20M is currently on vacation and is currently the only one that can definitively answer your query. They should return in the new year, hopefully you can continue your project in the meantime.

[Jeremy Gordon]

Hi Grant,
Any update from the engineering team? This issue is still persistent, and I’m worried its causing difficult to detect data losses.
A follow-up would be appreciated, to help us understand this error message and behavior.
Jeremy

[Grant [Tobii]]

Hi @jrgordon, apologies for the delay in response I’m afraid the HTC Vive Eye Pro is a product we no longer actively support and as the XR SDK is a free product, it is difficult to give priority to detailed questions of this type.

However, there is a means to interface directly to the eye-tracking data provider (in this case HTC), through the TobiiXR.Internal.Provider property. It might be possible to use that to update eye-tracking data faster than the application framerate by using:

var provider = TobiiXR.Internal.Provider as HTCProvider;
provider?.Tick();

Although we cannot guarantee its efficacy. Should this method not work, then we would, unfortunately, recommend you use the SRanipal SDK to achieve 120Hz capture rate.

[Jeremy Gordon]

Hi Grant,

Thanks for your reply, despite the Vive Pro Eye being no longer supported.

As a reminder, this is the warning message that I’m concerned about:

`
G2OM was initialized with a capacity of 30, but was supplied with 32. Purging overflowing elements.
`

It sounds like you are suggesting that this is a frame-rate issue. This would be a lower-impact problem for our study, but the warning itself seems to imply it relates to a limit on the number of objects tracked by G2OM, which would be a significant problem for us. Can you confirm the meaning of this warning, and whether it might imply that not all objects we’ve added for tracking are indeed reporting fixations?

Jeremy

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