Patent Description:
The present disclosure relates to the technical field of Virtual Reality (VR), and in particular to a foveated rendering method and system of a VR system based on monocular eyeball tracking.

With the progress of science and technology and the diversified development of market demands, VR systems are becoming more and more popular and have been applied in many fields, such as computer games, health and safety, industrial and educational training. As a few examples, mixed VR systems are being integrated into all aspects of life such as mobile communication devices, gaming machines, personal computers, movie theaters, theme parks, university laboratories, student classrooms, and hospital exercise rooms.

In general, VR is a form of reality that is adjusted in some manner prior to being presented to a user, and may include VR, Augmented Reality (AR), Mixed Reality (MR), or some combinations and/or derivative combinations of VR, AR, MR and the like.

A typical VR system includes one or more devices configured to present and display content to a user. For example, a VR system may include a Head Mounted Display (HMD) worn by a user and configured to output VR content to the user. At present, a VR system configured as an integrated device is popular. That is, various hardware devices such as a mobile computing processing unit and an image graphic renderer are integrated in the integrated device. At present, the integrated VR device is applied and popularized in many fields and scenarios, the requirements on quality parameters such as image definition of rendered contents presented by the integrated VR device in some scenarios are relatively high, and large challenges are brought to the processing capability and rendering capability of a mobile end of the integrated VR device.

At present, several solutions in different directions are provided. (<NUM>) Resources occupied by computing and rendering of virtual contents are reduced by reducing the display resolution of an entire head mounted integrated VR device. (<NUM>) By rendering the virtual contents of a part of regions in the center of a display screen at high resolution, and rendering and computing processing the virtual contents of other regions at reduced resolution, the computing resources and rendering resources of the virtual contents are optimized. (<NUM>) Eyeball fixation positions corresponding to binocular eyeball positions on a display screen region are obtained through an eyeball tracking technology, contents of regions corresponding to the eyeball fixation positions are rendered at high resolution, and contents of other regions are rendered and processed at low resolution.

According to the above solutions (<NUM>) and (<NUM>), negative influence is brought to the display definition of virtual contents presented by the integrated VR device to a certain extent, and the user experience is greatly influenced. In the solution (<NUM>), the problem of display definition of virtual contents of an eyeball fixation region of a user is solved to a certain extent. However, according to an eyeball tracking technology which is mainstream on the integrated VR device, two eyeball tracking modules need to be respectively arranged on left and right eye positions of a screen of an integrated VR device, and the same light source needs to be adopted in the two eyeball tracking modules, so that when in calibration or use, light rays emitted by the light sources in the two eyeball tracking modules are likely to interfere with each other, especially for a user wearing myopia glasses, computing result errors are increased, and the position accuracy of eyeball tracking is influenced.

Therefore, there is an urgent need for a foveated rendering method and system of a VR system based on monocular eyeball tracking, which can effectively avoid the problem that light sources of the two eyeball tracking modules are likely to interfere with each other in calibration or use, and can track regions of both eyes of a user with high precision in real time, so as to meet the eyeball foveated rendering requirements of the user.

<NPL>" discloses that there are several researches on 2D gaze tracking techniques for the 2D screen for the human-computer interaction. However, the researches for gaze-based interaction to the 3D stereo images or contents are not reported. The 3D display techniques are emerging now for the reality service. Moreover, the 3D interaction techniques are much more needed in the 3D contents service environments. This paper addresses gaze-based 3D interaction techniques on autostereoscopic display, such as parallax barrier or lenticular display. This paper presents our researches on 3D gaze estimation and gaze-based interaction to autostereoscopic display. The evaluation of our system is shown in terms of accuracy in gaze direction and gaze depth.

<CIT> discloses methods and systems for depth-based foveated rendering in the display system. The display system may be an augmented reality display system configured to provide virtual content on a plurality of depth planes using different wavefront divergence. Some embodiments include monitoring eye orientations of a user of a display system based on detected sensor information. A fixation point is determined based on the eye orientations, the fixation point representing a three-dimensional location with respect to a field of view. Location information of virtual objects to present is obtained, with the location information indicating three-dimensional positions of the virtual objects. Resolutions of at least one virtual object is adjusted based on a proximity of the at least one virtual object to the fixation point. The virtual objects are presented to a user by display system with the at least one virtual object being rendered according to the adjusted resolution.

<NPL>" discloses that many applications such as data visualization or object recognition benefit from accurate knowledge of where a person is looking at. We present a system for accurately tracking gaze positions on a three dimensional object using a monocular. We accomplish this by <NUM>) using digital manufacturing to create stimuli whose geometry is know to high accuracy, <NUM>) embedding fiducial markers into the manufactured objects to reliably estimate the rigid transformation of the object, and, <NUM>) using a perspective model to relate pupil positions to 3D locations. This combination enables the efficient and accurate computation of gaze position on an object from measured pupil positions. We validate the accuracy of our system experimentally, achieving an angular resolution of <NUM><NUM> and a <NUM>% depth error using a simple calibration procedure with <NUM> points.

<NPL>" discloses that 3D gaze information is important for scene-centric attention analysis, but accurate estimation and analysis of 3D gaze in real-world environments remains challenging. We present a novel 3D gaze estimation method for monocular head-mounted eye trackers. In contrast to previous work, our method does not aim to infer 3D eyeball poses, but directly maps 2D pupil positions to 3D gaze directions in scene camera coordinate space. We first provide a detailed discussion of the 3D gaze estimation task and summarize different methods, including our own. We then evaluate the performance of different 3D gaze estimation approaches using both simulated and real data. Through experimental validation, we demonstrate the effectiveness of our method in reducing parallax error, and we identify research challenges for the design of 3D calibration procedures.

In view of the above problem, embodiments of the present disclosure provide a foveated rendering method and system of a VR system based on monocular eyeball tracking, which can solve the problems that since two eyeball tracking modules are respectively arranged on left and right eye positions of a screen of an integrated VR device and the same light source is adopted in the two eyeball tracking modules, when in calibration or use, light rays emitted by the light sources in the two eyeball tracking modules are likely to interfere with each other, especially for a user wearing myopia glasses, computing result errors are increased, and the position accuracy of eyeball tracking is influenced.

A foveated rendering method of a VR system based on monocular eyeball tracking provided by an embodiment of the present disclosure includes:.

In at least one exemplary embodiment, the operation of obtaining a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system includes:.

In at least one exemplary embodiment, the light is infrared light or visible light.

In at least one exemplary embodiment, in a case where the light is infrared light, at least one infrared light emitting source assembly emits infrared light, and an infrared light tracking camera captures infrared light reflected by the monocular eyeball of the user, and obtains the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected infrared light through the computer vision technology.

In at least one exemplary embodiment, the infrared light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device, and the at least one infrared light emitting source assembly is arranged on the periphery of the infrared light tracking camera.

In at least one exemplary embodiment, when the infrared light tracking camera tracks a position of the monocular eyeball of the user, the infrared light tracking camera captures an infrared tracking image formed by the reflected infrared light of the at least one infrared light emitting source assembly on the monocular eyeball, and obtains the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system through the computer vision technology.

In at least one exemplary embodiment, in a case where the light is visible light, at least one visible light source assembly emits visible light, and a visible light tracking camera captures visible light reflected by the monocular eyeball of the user, and obtains the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected visible light through the computer vision technology.

In at least one exemplary embodiment, the visible light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in an integrated VR device, and the at least one visible light source assembly is arranged on the periphery of the visible light tracking camera.

In at least one exemplary embodiment, the visible light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device, and the at least one visible light source assembly is arranged on the periphery of the visible light tracking camera.

An embodiment of the present disclosure provides a foveated rendering system of a VR system based on monocular eyeball tracking, configured to implement the foregoing foveated rendering method of the VR system based on monocular eyeball tracking. The foveated rendering system includes: a display screen, arranged in an integrated VR device, of the VR system, a monocular tracking module arranged in the integrated VR device, an IPD adjusting function module, a processor, and a rendering module.

The monocular tracking module is configured to obtain a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system.

The IPD adjusting function module is configured to be adapted to both eyes of the user so as to obtain the IPD corresponding to the binocular pupil distance of the user.

The processor is configured to calculate a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position, and determine main rendering regions by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively.

The rendering module is configured to perform main rendering in the main rendering regions, and perform matched rendering on regions except the main rendering regions in the display screen of the VR system. A rendering resolution of the main rendering is higher than a rendering resolution of the matched rendering, wherein the obtaining an IPD corresponding to a binocular pupil distance of the user comprises: adapting an IPD adjusting function module in an integrated VR device to both eyes of the user to obtain the IPD corresponding to the binocular pupil distance of the user.

In at least one exemplary embodiment, the monocular tracking module is an infrared tracking module or a visible light tracking module.

In at least one exemplary embodiment, the infrared tracking module includes at least one infrared light emitting source assembly and an infrared light tracking camera.

The at least one infrared light emitting source assembly is configured to emit infrared light.

The infrared light tracking camera is configured to capture infrared light reflected by the monocular eyeball of the user, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected infrared light through a computer vision technology.

In at least one exemplary embodiment, the infrared light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device.

The at least one infrared light emitting source assembly is arranged on the periphery of the infrared light tracking camera.

In at least one exemplary embodiment, when the infrared light tracking camera tracks a position of the monocular eyeball of the user, the infrared light tracking camera is configured to capture an infrared tracking image formed by the reflected infrared light of the at least one infrared light emitting source assembly on the monocular eyeball, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system through the computer vision technology.

In at least one exemplary embodiment, the visible light tracking module includes at least one visible light source assembly and a visible light tracking camera.

The at least one visible light source assembly is configured to emit visible light.

The visible light tracking camera is configured to capture visible light reflected by the monocular eyeball of the user, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected visible light through the computer vision technology.

In at least one exemplary embodiment, the visible light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device.

The at least one visible light source assembly is arranged on the periphery of the visible light tracking camera.

In at least one exemplary embodiment, trackable light of the visible light tracking camera is in a band range of <NUM>-<NUM>.

In at least one exemplary embodiment, when the visible light tracking camera tracks a position of the monocular eyeball of the user, the visible light tracking camera is configured to capture a tracking image formed by the reflected visible light of the at least one visible light source assembly on the monocular eyeball, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system through the computer vision technology.

An embodiment of the present invention provides a non-transitory computer-readable storage medium, having a computer program stored thereon which, when executed by a processor, implements the method described in any one of the foregoing embodiments or exemplary embodiments.

As can be seen from the above technical solution, according to the foveated rendering method and system of the VR system based on monocular eyeball tracking provided by the embodiments of the present disclosure, a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system is obtained, and then an IPD corresponding to a binocular pupil distance of the user is obtained, so as to calculate a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position. Then, main rendering regions are determined by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively. High-resolution main rendering is performed in the main rendering regions, and matched rendering is performed on regions except the main rendering regions in the display screen of the VR system, so that a high image definition is presented for both eyes of a user, and user experience is improved. Moreover, the problems that light rays emitted by light sources in binocular eyeball tracking are likely to interfere with each other, calculation result errors are large and the position accuracy of eyeball tracking is influenced can be solved by monocular eyeball tracking. Moreover, high-precision tracking is performed on regions of the eyes of the user in real time, and the requirements of eyeball foveated rendering of the user are greatly met.

Other objects and results of the present disclosure will become more apparent and appreciated by reference to the following description taken in conjunction with the accompanying drawings, and as the disclosure becomes more fully understood. In the drawings:.

In some scenarios, the requirements on quality parameters, such as image definition, of rendered contents presented by an integrated VR device are relatively high. If a binocular tracking technology is adopted, eyeball fixation positions corresponding to binocular eyeball positions on a display screen region are obtained, contents of regions corresponding to the eyeball fixation positions are rendered at high resolution, and contents of other regions are rendered and processed at low resolution. In this way, the problem of display definition of virtual contents of an eyeball fixation region of a user is solved to a certain extent. However, according to an eyeball tracking technology which is mainstream on the integrated VR device, two eyeball tracking modules need to be respectively arranged on left and right eye positions of a screen of an integrated VR device, and the same light source needs to be adopted in the two eyeball tracking modules, so that when in calibration or use, light rays emitted by the light sources in the two eyeball tracking modules are likely to interfere with each other, especially for a user wearing myopia glasses, computing result errors are increased, and the position accuracy of eyeball tracking is influenced.

Aiming at the above problem, embodiments of the present disclosure provide a foveated rendering method and system of a VR system based on monocular eyeball tracking. Exemplary embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

In order to illustrate the foveated rendering method and system of a VR system based on monocular eyeball tracking provided by the embodiment of the present disclosure, <FIG> exemplarily illustrates a foveated rendering method of a VR system based on monocular eyeball tracking according to an embodiment of the present disclosure, and <FIG> exemplarily illustrates a foveated rendering system of a VR system based on monocular eyeball tracking according to an embodiment of the present disclosure.

The following description of the exemplary embodiments is only illustrative, and is not used as any limitation for the present disclosure and the application or use of the present disclosure. Technologies and devices known by those having ordinary skill in the related art may not be discussed in detail. However, where appropriate, the technologies and the devices shall be regarded as part of the description.

As shown in <FIG>, a foveated rendering method of a VR system based on monocular eyeball tracking provided by an embodiment of the present disclosure includes the following operations.

At S110, a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system is obtained.

At S120, an IPD corresponding to a binocular pupil distance of the user is obtained, and a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system is calculated according to the IPD and the first monocular mapping position.

At S130, main rendering regions are determined by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively.

At S140, main rendering is performed in the main rendering regions, and matched rendering is performed on regions except the main rendering regions in the display screen of the VR system. A rendering resolution of the main rendering is higher than a rendering resolution of the matched rendering.

As shown in <FIG>, the process that a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system is obtained in operation S110 includes the following operations.

At S11, light is emitted to the monocular eyeball of the user. The light may be infrared light or visible light. The monocular eyeball may be a left eye or a right eye.

At S12, light reflected by the monocular eyeball of the user is captured, and the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system is obtained according to a relative position of the reflected infrared light through a computer vision technology.

As described above, according to the foveated rendering method of the VR system based on monocular eyeball tracking provided by the present disclosure, a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system is obtained, and then an IPD corresponding to a binocular pupil distance of the user is obtained, so as to calculate a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position. Then, main rendering regions are determined by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively. High-resolution main rendering is performed in the main rendering regions, and matched rendering is performed on regions except the main rendering regions in the display screen of the VR system, so that a high image definition is presented for both eyes of a user, and user experience is improved. Moreover, the problems that light rays emitted by light sources in binocular eyeball tracking are likely to interfere with each other, calculation result errors are large and the position accuracy of eyeball tracking is influenced can be solved by monocular eyeball tracking. Moreover, high-precision tracking is performed on regions of the eyes of the user in real time, and the requirements of eyeball foveated rendering of the user are greatly met.

As shown in <FIG>, the embodiment of the present disclosure provides a foveated rendering system <NUM> of a VR system based on monocular eyeball tracking. The foveated rendering system <NUM> is configured to implement the foregoing foveated rendering method of the VR system based on monocular eyeball tracking, and includes: a display screen <NUM> of the VR system arranged in an integrated VR device, a monocular tracking module <NUM> arranged in the integrated VR device, an IPD adjusting function module <NUM>, a processor <NUM>, and a rendering module <NUM>.

The monocular tracking module <NUM> is configured to obtain a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen <NUM> of the VR system.

The IPD adjusting function module <NUM> is configured to be adapted to both eyes of the user so as to obtain the IPD corresponding to the binocular pupil distance of the user. In the present embodiment, the IPD adjusting function module <NUM> is arranged in the integrated VR device. The user can adjust an IPD value (Inter Pupilary Distance) suitable for the binocular pupil distance of the user according to the binocular pupil distance of the user, so that a distance between two cylindrical lenses of the integrated VR device is matched with the binocular pupil distance of the user.

The processor <NUM> is configured to calculate a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position, and determine main rendering regions by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively. The preset threshold is not specifically limited in the present embodiment, and is adjustable according to specific application conditions.

The rendering module <NUM> is configured to perform main rendering in the main rendering regions, and perform matched rendering on regions except the main rendering regions in the display screen of the VR system. A rendering resolution of the main rendering is higher than a rendering resolution of the matched rendering. Therefore, contents of regions corresponding to the eyeball fixation positions are rendered at high resolution, and contents of other regions are rendered and processed at low resolution. The overall calculation speed is increased, high-precision tracking is performed on a binocular position region of the user in real time, and the requirements of eyeball foveated rendering of the user are met to a great extent.

In the embodiment shown in <FIG>, the monocular tracking module <NUM> is an infrared tracking module A or a visible light tracking module B.

If the infrared tracking module A is adopted, the infrared tracking module A includes at least one infrared light emitting source assembly A-<NUM> and an infrared light tracking camera A-<NUM>.

The at least one infrared light emitting source assembly A-<NUM> is configured to emit infrared light.

The infrared light tracking camera A-<NUM> is configured to capture infrared light reflected by the monocular eyeball of the user, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected infrared light through a computer vision technology.

In the present embodiment, an infrared light tracking camera is adopted, and the infrared light tracking camera is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device. The at least one infrared light emitting source assembly is arranged on the periphery of the infrared light tracking camera. That is, a certain number of infrared light emitting source assemblies are arranged near the periphery of the infrared light tracking camera. For example, the monocular eyeball of the user is the right eye. When the infrared light tracking camera tracks a position of the monocular eyeball of the user, an infrared tracking image formed by the reflected infrared light of the at least one infrared light emitting source assembly on the monocular eyeball is captured, and then position information corresponding to the eyeball position on the right eye screen is obtained through a computer vision technology.

If the visible light tracking module B is adopted, the visible light tracking module B includes at least one visible light source assembly B-<NUM> and a visible light tracking camera B-<NUM>.

The at least one visible light source assembly B-<NUM> is configured to emit visible light.

The visible light tracking camera B-<NUM> is configured to capture visible light reflected by the monocular eyeball of the user, and obtain the first monocular mapping position, corresponding to the monocular eyeball of the user, on the display screen of the VR system according to a relative position of the reflected visible light through the computer vision technology.

In the present embodiment, a visible light tracking camera B-<NUM> is arranged. The visible light tracking camera B-<NUM> may be a color camera or a monochrome gray scale camera. The visible light tracking camera B-<NUM> is arranged at a position corresponding to the monocular eyeball of the user in the integrated VR device, and trackable light of the visible light tracking camera is in a band range of <NUM>-<NUM>. The at least one visible light source assembly B-<NUM> is arranged on the periphery of the visible light tracking camera. That is, a certain number of visible light source assemblies B-<NUM> are provided near the periphery of the visible light tracking camera. The at least one visible light source assembly B-<NUM> not only includes visible light, but also includes any light source assembly whose light can be captured by the visible light tracking camera B-<NUM>. A band of the at least one visible light source assembly B-<NUM> is <NUM>-<NUM>. The at least one visible light source assembly may be at least one visible light source assembly in a traditional sense, and may also be at least one infrared light emitting source assembly with a band of <NUM>. For example, the monocular eyeball of the user is the right eye. When the visible light tracking camera tracks the eyeball position of the user, a tracking image formed by the reflected visible light of the at least one visible light source assembly on the monocular eyeball is captured, and then position information corresponding to the eyeball position on the right eye screen is obtained through a computer vision technology.

As can be seen from the above implementation mode, according to the foveated rendering system of the VR system based on monocular eyeball tracking provided by the present disclosure, a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system is obtained, and then an IPD corresponding to a binocular pupil distance of the user is obtained, so as to calculate a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position. Then, main rendering regions are determined by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively. High-resolution main rendering is performed in the main rendering regions, and matched rendering is performed on regions except the main rendering regions in the display screen of the VR system, so that a high image definition is presented for both eyes of a user, and user experience is improved. Moreover, the problems that light rays emitted by light sources in binocular eyeball tracking are likely to interfere with each other, calculation result errors are large and the position accuracy of eyeball tracking is influenced can be solved by monocular eyeball tracking. Moreover, high-precision tracking is performed on regions of the eyes of the user in real time, and the requirements of eyeball foveated rendering of the user are greatly met.

Claim 1:
A foveated rendering method of a Virtual Reality (VR) system based on monocular eyeball tracking, comprising:
obtaining a first monocular mapping position, corresponding to a monocular eyeball of a user, on a display screen of the VR system (S110);
obtaining an Inter Pupilary Distance (IPD) corresponding to a binocular pupil distance of the user, and calculating a second monocular mapping position, corresponding to the other monocular eyeball of the user, on the display screen of the VR system according to the IPD and the first monocular mapping position (S120);
determining main rendering regions by taking the first monocular mapping position and the second monocular mapping position as circle centers and preset thresholds as radiuses respectively (S130); and
performing main rendering in the main rendering regions, and performing matched rendering on regions except the main rendering regions in the display screen of the VR system, wherein a rendering resolution of the main rendering is higher than a rendering resolution of the matched rendering (S140),
wherein the obtaining an IPD corresponding to a binocular pupil distance of the user comprises:
adapting an IPD adjusting function module in an integrated VR device to both eyes of the user to obtain the IPD corresponding to the binocular pupil distance of the user.