Earlier this month, Tobii and Pimax released eye-tracking on the Pimax Crystal, and with a public AMA session on Reddit (r/Pimax), we’ve answered the top questions. Let’s go!
Foveated Transport for standalone mode
Omniwhatever: “One of the features I’ve seen Tobii mention before was the idea of foveated transport, that is using the same principles of foveated rendering to compress the image in your peripheral but not where you’re looking, in order to save on bandwidth and be unnoticeable, like DFR but for bandwidth instead of performance. I even saw some whitepapers claiming 2 years back that 5:1 ratio could potentially be achieved with it when combined with existing forms of compression like DSC, give or take a bit depending on system latency. Is this something that we could see at some point for the Crystal and/or 12k to get higher refresh rates and get around bandwidth limits or that Tobii is pursuing? I don’t think there have been any notable consumer examples of this and 120hz on the Crystal’s pushing limits pretty high, with the 12k going even further.
Could this potentially be used over wireless in order to help mitigate the limited bandwidth it has vs wired DisplayPort as well?”
Thank you, Omni for this suggestion/question! Like a lot of questions about future technology, the answer is always a tad boring: we’re investigating it.
Longer version: Our latest firmware version supports both fixed foveated rendering and dynamic foveated rendering, providing users with more rendering options to optimize the VR experience.
Regarding the concept of foveated transport you mentioned, we understand that this can compress images to reduce bandwidth consumption. This technique can be viewed as complementary to Dynamic Foveated Rendering (DFR), focusing on reducing bandwidth requirements rather than performance optimization.
We’re still conducting internal R&D attempts as soon as possible to explore the possibility of applying this technology to products.
Dynamic Distortion Profile Correction
Omniwhatever: “I’ve also seen some pages from Tobii about dynamic distortion profile correction. Is this also something that could one day make it to the Crystal and perhaps help with some of the visual issues people have noted, such as color shift or CA? Or is that maybe more something for the 12k given the much wider FoV and more complex optical challenges I imagine are associated with it vs the Crystal?”
Stock-Parsnip-4054: “I’ve also seen some pages from Tobii about dynamic distortion profile correction. Is this also something that could one day make it to the Crystal and perhaps help with some of the visual issues people have noted, such as color shift or CA? Or is that maybe more something for the 12k given the much wider FoV and more complex optical challenges I imagine are associated with it vs the Crystal? This is also my main question. Let’s hope that the blue/purple/color shifts will finally get solved!”
Hi Omni and Stock-Parsnip, the same as the question above. We’ll carefully study dynamic distortion correction technology to understand its role in optimizing the visual experience and solving visual problems such as color shift or chromatic aberration. At the same time, we will also consider whether this technology is suitable for our products Crystal and 12K, and the possibilities under different fields of view and optical challenges.
Availability of Tobii Pro SDK / Ocumen
YamaPii: “Will developers who want to utilize the full capabilities of the eye tracking hardware (e.g. to detect pupil dilation and eye openness amount, or gain access to raw eye image streams for analytics) be able to use Tobii’s more advanced solutions like the Pro SDK or Ocumen?”
Thanks for your question. Tobii Ocumen is usually used to develop advanced applications for enterprise headsets. Please check Tobii Ocumen | Tobii XR Devzone for the latest information about supported headsets.
Greenonetrailmix: “Tobii has eye tracking values that are not enabled for the Pimax Crystal that other VR headsets have with Tobii hardware, one special case is the Vive Pro Eye. The best eye-tracked headset on the market. Why haven’t we seen some extra values that the hardware has for Social VR applications such as VRChat. The community as a whole for social VR wants these extra features integrated. Missing features in question: Pupil diameter, eye openness, convergence distance, and gradual non-binary blinking.”
Thanks for your question. While integrated eye tracking introduces the capacity to support an array of eye-tracking-enabled features, it’s important to prioritize those that provide the best value to users for the target use cases. For example, the mentioned Pupil diameter feature is a scientific purpose signal available via Tobii Ocumen, an advanced toolkit that provides developers with a framework to record, organize, and analyze biometrics as well as rapidly build and deploy scientific-grade VR products in specialized industries like healthcare and medical assessment. Pimax Crystal, as a high-end gaming VR headset, is currently not compatible with Tobii Ocumen.
Non-typical shapes of eyes
SepticKnave39: “I saw quite an old post (not Crystal-related but Tobii eye tracking related) about eye tracking not working with eyes that aren’t typical shape, for example, eyes that have had LASIK Surgery. Has this been resolved? Does crystal eye tracking work with eyes that have undergone LASIK and similar surgeries?”
Yes, Tobii eye tracking supports different eye shapes and it supports people who have had LASIK surgery for vision correction.
Digital Lens plugin (Almalence)
VaderDPL: “Any plans to implement eye-tracking-based dynamic image correction to expand the sweet spot and improve edge-to-edge clarity such as this plugin from Digital Lens?”
Context: ‘Digital Lens’ Plugin for Eye-tracking Headsets Improves Visual Clarity
Mbucchia kinda answered this for us: “I tried the Almalence on my G2 Omnicept and it wasn’t very conclusive:
- Improvement in clarity was only a little bit better than CAS sharpening and only in the sweet spot of the lens.
- It created some really (really) bad color shifts in some situations. Text appearing double. With instruments in X-Plane 12, it made entire displays show double.
- The Almalence program crashed with most applications I tested. Out of a dozen of apps, only X-Plane 12 actually did not crash with it.”
Thank you for your suggestion, as always with potential future technology, the answer is a bit formal and boring. We have already taken note of this, as it has potentially a good improvement in picture clarity. We will arrange for internal R&D personnel to verify it. Once there is new progress, we will communicate in a timely manner.
Nvidia VRSS 2
Greenonetrailmix: “Is Pimax going to implement Nvidia VRSS 2 support for the Crystal?
https://developer.nvidia.com/blog/nvidia-vrss-2-dynamic-foveated-rendering-no-assembly-required/“This is on our roadmap for software development. Please don’t mistake that for a guarantee that this feature will come out. We will communicate the latest news in a timely manner.
IPD offset
Henningdale: “My IPD is 63 near and 65 far. Auto IPD sets it to 60,5. Should I manually change it or not?”
Due to Crystal’s tilted panels and lenses, it’s possible that the Auto-IPD will set a slightly different value. This is explained further here: Some thoughts on the IPD discrepancy
Any more questions? Please head over to Pimax’s official Discord server and follow Tobii online.