Dynamic haptic retargeting can be implemented using world warping techniques and body warping techniques. World warping is applied to improve an alignment between a virtual object and a physical object, while body warping is applied to redirect a user's motion to increase a likelihood that a physical hand will reach the physical object at the same time a virtual representation of the hand reaches the virtual object. Threshold values and/or a combination of world warping a body warping can be used to mitigate negative impacts that may be caused by using either technique excessively or independently.

BACKGROUND

Virtual reality systems are becoming ever more popular, with consumer-level head-mounted displays and motion tracking devices leading to the creation of a large number of immersive experiences. A primary objective in many virtual reality systems is to establish a sense of presence for the user. While optics, rendering, and audio technologies have improved substantially, resulting in photorealistic renderings through which users can be convinced by the illusion of reality, a sense of touch expected when reaching out and grabbing virtual objects is still lacking.

Haptics is a term used to represent various aspects of a user's sense of touch. One method for enabling users to experience a sense of touch when interacting with virtual objects is referred to herein as passive haptics. Mapping respective physical objects to each virtual object with which a user is expected to interact can result in a compelling tactile sensation when reaching out and touching a virtual object. However, this illusion requires each virtual object to have a corresponding physical prop of the same size and shape and in the same location. This can result in a very complicated physical environment, and keeping the physical environment synchronized with the virtual environment can be difficult or even impossible.

SUMMARY

This disclosure describes techniques for dynamic haptic retargeting. A single physical object can be mapped to multiple virtual objects such that when a user reaches out to touch any one of the virtual objects, the dynamic haptic retargeting techniques result in redirection of the user's physical movement so that, when it appears to the user that they are touching the virtual object, they are actually touching the physical object. A variety of techniques can be used to implement dynamic haptic retargeting, including, but not limited to, world warping, body warping, and a combination of world and body warping.

According to an example world warping technique, the virtual environment is shifted with regard to the physical environment, for example, by translation or rotation. According to an example body warping technique, the virtual representation of a user's hand is manipulated to passively redirect the user's physical motions while reaching for a virtual object.

In at least some scenarios, by applying a combination of world warping and body warping and/or by enforcing a maximum warp for either or both, negative effects such as detectable world warping, motion sickness, and/or virtual body misalignment may be reduced.

DETAILED DESCRIPTION

Overview

Techniques for dynamic haptic retargeting are described herein. When a user is interacting with a virtual reality or mixed reality environment, repurposing a single physical object to provide passive haptic sensation for a variety of virtual objects, can increase the user's sense of presence within the environment and can increase the overall quality of the experience. As an example, a user may be interacting with a virtual reality environment that includes multiple similar objects. As defined within the virtual reality environment, the virtual objects can be picked up and their positions manipulated by the user. Using the dynamic haptic retargeting techniques described herein, a single physical object having similar size and shape to the virtual objects represented in the virtual reality can be used to provide passive haptic feedback to the user when the user touches any of the virtual objects.

Dynamic haptic retargeting enables a single physical object to be mapped to multiple virtual objects by altering the user's perception of the user's physical position with respect to the virtual environment. For example, if there are two virtual objects and both are mapped to a single physical object, as the user reaches for either of the virtual objects, the user's physical movements are dynamically redirected toward the single physical object, while visually the user sees a virtual representation of the user's hand reaching toward the virtual object the user has chosen.

Dynamic haptic retargeting techniques, as described herein, include world warping, body warping, and a combination of the two. According to a world warping technique, as a user reaches for a virtual object, the virtual environment with which the user is interacting is rotated to align a position of the virtual object with a position of the physical object. According to a body warping technique, as a user reaches for a virtual object, a position of a virtual representation of the user's hand and arm within the virtual environment is altered, causing the user to adjust the direction of their movement so that the user's hand reaches the physical object as the virtual representation of the user's hand reaches the virtual object.

Both world warping and body warping techniques have drawbacks. For example, if applied excessively, world warping can cause the user to feel motion sickness. Furthermore, even smaller amounts of world warping (e.g., not significant enough to cause motion sickness) may be visibly detected by a user, which may result in the user becoming aware that the physical object is not the same as the virtual object. As another example, if applied excessively, body warping can result in a virtual representation of the user's arm or hand that appears out of alignment with the rest of the user's body or the virtual representation of the user's arm may appear unnaturally deformed.

Effective haptic retargeting can be achieved by dynamically applying world warping, body warping, or a combination of world warping and body warping as a user interacts with a virtual environment.

Illustrative Environment

FIG. 1illustrates an example environment100in which dynamic haptic retargeting can be implemented. In the illustrated example, a user102is in a physical environment, which includes a table104and a physical object106. A virtual environment is mapped to the physical environment, and includes virtual object108and virtual object110.

Example environment100also include any number of a devices to enable the user102to interact with the virtual environment. For example, example environment100includes device112, implemented as a head-mounted display, camera114, and hand tracking device116.

Device112is illustrated as a head-mounted display, but is representative of any device that enables a user to interact with virtual objects in a virtual environment. In the illustrated example, device112includes a processor118, one or more sensors120, input interface122, and memory124, each operably connected to the others such as via a bus125. Bus125may include, for example, one or more of a system bus, a data bus, an address bus, a PCI bus, a Mini-PCI bus, and any variety of local, peripheral, and/or independent buses.

Processor118can represent, for example, a CPU-type processing unit, a GPU-type processing unit, a field-programmable gate array (FPGA), another class of digital signal processor (DSP), or other hardware logic components that may, in some instances, be driven by a CPU. For example, and without limitation, illustrative types of hardware logic components that can be used include Application-Specific Integrated Circuits (ASICs), Application-Specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.

Sensors120may include, for example, a depth map sensor, a camera, a light field sensor, a gyroscope, a sonar sensor, an infrared sensor, a compass, an accelerometer, and/or any other component for detecting a position or movement of the device112and/or other objects. Sensors120can also enable the generation of data characterizing interactions, such as user gestures, with the device112.

I/O (input/output) interface122is configured to enable device112to receive input or send output. For example, input may be received via a touch screen, a camera to receive gestures, a microphone, a keyboard, a mouse, or any other type of input device. Similarly, for example, output may be presented via a display, speakers, or any other output device.

Memory124can store instructions executable by the processor118. For example, memory124can store a virtual reality system126that can be executed to enable user interaction with virtual objects within a virtual environment. Furthermore memory124can store a haptic retargeting system128that can be executed to support user interaction with the virtual environment through the use of dynamic haptic retargeting.

Camera114may be implemented to capture motions of the user. Data generated by camera114may then be used, for example, to generate a virtual representation of a user's hand within the virtual environment. In an example implementation, data from camera114is communicated to haptic retargeting system128via, for example, a network130.

Example environment100may also include a server computer system132. Example server132includes a processor134and a memory136, operably connected to each other such as via a bus137. Bus137may include, for example, one or more of a system bus, a data bus, an address bus, a PCI bus, a Mini-PCI bus, and any variety of local, peripheral, and/or independent buses. An operating system138and all or part of virtual reality system126and/or haptic retargeting system128may be stored in memory136and executed on processor134.

Memory124and memory136are examples of computer-readable media. As described above, memory124and memory136can store instructions executable by processors118and134. Computer-readable media (e.g., memory124and/or memory136) can also store instructions executable by external processing units such as by an external CPU, an external GPU, and/or executable by an external accelerator, such as an FPGA type accelerator, a DSP type accelerator, or any other internal or external accelerator. In various examples at least one CPU, GPU, and/or accelerator is incorporated in device112, while in some examples one or more of a CPU, GPU, and/or accelerator is external to device112.

Computer-readable media may include computer storage media and/or communication media. Computer storage media can include volatile memory, nonvolatile memory, and/or other persistent and/or auxiliary computer storage media, removable and non-removable computer storage media implemented in any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. Memory124and memory136can be examples of computer storage media. Thus, the memory124and memory136includes tangible and/or physical forms of media included in a device and/or hardware component that is part of a device or external to a device, including but not limited to random-access memory (RAM), static random-access memory (SRAM), dynamic random-access memory (DRAM), phase change memory (PRAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc read-only memory (CD-ROM), digital versatile disks (DVDs), optical cards or other optical storage media, magnetic cassettes, magnetic tape, magnetic disk storage, magnetic cards or other magnetic storage devices or media, solid-state memory devices, storage arrays, network attached storage, storage area networks, hosted computer storage or any other storage memory, storage device, and/or storage medium that can be used to store and maintain information for access by a computing device.

In contrast to computer storage media, communication media may embody computer-readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave, or other transmission mechanism. As defined herein, computer storage media does not include communication media. That is, computer storage media does not include communications media consisting solely of a modulated data signal, a carrier wave, or a propagated signal, per se.

Device112and/or server130can belong to a variety of categories or classes of devices such as traditional server-type devices, desktop computer-type devices, mobile-type devices, special purpose-type devices, embedded-type devices, and/or wearable-type devices. Thus, although illustrated as a single type of device, device112and server130can include a diverse variety of device types and are not limited to a particular type of device. Device112and server130can represent, but are not limited to, desktop computers, server computers, web-server computers, personal computers, mobile computers, laptop computers, tablet computers, wearable computers, implanted computing devices, telecommunication devices, thin clients, terminals, personal data assistants (PDAs), game consoles, gaming devices, work stations, media players, personal video recorders (PVRs), set-top boxes, cameras, integrated components for inclusion in a computing device, appliances, or any other sort of computing device.

Network128can include, for example, public networks such as the Internet, private networks such as an institutional and/or personal intranet, or some combination of private and public networks. Network128can also include any type of wired and/or wireless network, including but not limited to local area networks (LANs), wide area networks (WANs), satellite networks, cable networks, Wi-Fi networks, WiMax networks, mobile communications networks (e.g., 3G, 4G, and so forth) or any combination thereof. Network128can utilize communications protocols, including packet-based and/or datagram-based protocols such as internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), or other types of protocols. Moreover, network128can also include a number of devices that facilitate network communications and/or form a hardware basis for the networks, such as switches, routers, gateways, access points, firewalls, base stations, repeaters, backbone devices, and the like.

In some examples, network128can further include devices that enable connection to a wireless network, such as a wireless access point (WAP). Examples support connectivity through WAPs that send and receive data over various electromagnetic frequencies (e.g., radio frequencies), including WAPs that support Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (e.g., 802.11g, 802.11n, and so forth), and other standards.

FIG. 2illustrates an example mapping of a virtual environment202to a physical environment204. As discussed above with reference toFIG. 1, physical environment204includes a table104and a physical object106, illustrated as a block or cube. Similarly, virtual environment202includes a virtual table206, virtual object108, and virtual object110. View208illustrates the virtual environment202mapped onto the physical environment204such that table104and virtual table206are aligned, and each of physical object106and virtual objects108and110appear to be resting on the table.

Although not illustrated, device112, camera114, and server132may each also include a network interface to facilitate communication via network130.

World Warping and Body Warping

FIG. 3illustrates an example of dynamic world warping as a user reaches toward a virtual object. View302corresponds to view208ofFIG. 2, which illustrates a virtual environment mapped onto a physical environment. Furthermore, view302includes a virtual representation of a user's hand304, as the user reaches toward virtual object108. Because physical object106and virtual object108are not aligned with one another, if the reaches for virtual object108, the user will not physically come in contact with physical object106. World warping is a technique that can be used to enable dynamic haptic retargeting by realigning the virtual environment202with the physical environment204so that the virtual object108being reached for is aligned with the physical object106. View306illustrates a result of applying a world warping to move the virtual environment202with respect to the physical environment204to align virtual object108with physical object106.

FIG. 4illustrates an example of dynamic body warping as a user reaches toward a virtual object. View402corresponds to view208ofFIG. 2, which illustrates a virtual environment mapped onto a physical environment. Furthermore, view402includes a virtual representation of a user's hand404, as the user reaches toward virtual object108. As in the scenario described above with reference toFIG. 3, because physical object106and virtual object108are not aligned with one another, if the user reaches for virtual object108, the user will not physically come in contact with physical object106. Body warping is another technique that can be used to enable dynamic haptic retargeting by altering the location of the virtual representation of the user's hand404to cause the user to change their physical motion such that the user's physical hand will come in contact with physical object106when the virtual representation of the user's hand404comes in contact with the virtual object108.

View406illustrates an example body warping in which the virtual representation of the user's hand404is moved to the left408to a new location404′. Based on this adjustment, the user will physically move their hand further to the right, thereby physically reaching for the physical object106while it appears the virtual representation of the user's hand404′ is reaching for the virtual object108.

FIG. 5illustrates an example of dynamic haptic retargeting using a combination of world warping and body warping. View502corresponds to view208ofFIG. 2, which illustrates a virtual environment mapped onto a physical environment. Furthermore, view502includes a virtual representation of a user's hand504, as the user reaches toward virtual object108. As in the scenarios described above with reference toFIGS. 2 and 3, because physical object106and virtual object108are not aligned with one another, if the reaches for virtual object108, the user will not physically come in contact with physical object106. View506illustrates a result of a dynamic world warping which results in virtual object108being closer to physical object106. View508illustrates a result of a dynamic body warping applied after the dynamic world warping shown in view506. By applying a combination of world warping and body warping, each can be applied to a lesser degree than if only one is applied.

Example Haptic Retargeting System

FIG. 6illustrates select components of an example haptic retargeting system128, which includes virtual target detection module602, physical target selection module604, and warp control module606. As described above with reference toFIG. 1, one or more individual components, or portions of individual components, of the haptic retargeting system128can be implemented as part of device112and/or server132, or any other device communicatively connected to device112.

Target detection module602determines a virtual object toward which a user is reaching. Any number of techniques may be used to detect the target virtual object. For example, a user may indicate the target via a user interface selection or via a voice command. As another example, device112may include sensors to facilitate gaze detection, and a target virtual object may be detected based on a determined gaze direction. As another example, a vector may be generated based on a user's reach, and a virtual object nearest an intersection with the vector may be detected as the target virtual object.

Physical target selection module604selects a physical object to be mapped to the detected target virtual object. Any number of techniques may be used to select the target physical object. As an example, if multiple physical objects are in the physical environment, the physical object closest to the target virtual object may be selected. As another example, if multiple physical objects are in the physical environment, a physical object that most closely resembles the target virtual object mat by selected. In another example, the closest physical object that resembles the target virtual object may be selected as the target physical object. In yet another example, any of the above criteria may be used in conjunction with determining a physical object for which a path between the user's physical hand and the physical object does not intersect any other physical or virtual objects.

Warp control module606controls the application of world warp and/or body warp to facilitate dynamic haptic retargeting. Warp control module606includes world warp module608and body warp module610. World warp module608dynamically applies world warping to incrementally alter the alignment of the virtual environment with the physical environment as a user reaches toward a virtual object. Body warp module610dynamically applies body warping to incrementally modify the location of the virtual representation of the user's hand as the user reaches toward the virtual object.

Methods for Dynamic Haptic Retargeting

FIGS. 7-12illustrate example methods for performing dynamic haptic retargeting. The example processes are illustrated as collections of blocks in logical flow graphs, which represent sequences of operations that can be implemented in hardware, software, or a combination thereof. The blocks are referenced by numbers. In the context of software, the blocks represent computer-executable instructions stored on one or more computer-readable media that, when executed by one or more processing units (such as hardware microprocessors), perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described blocks can be combined in any order and/or in parallel to implement the process.

FIG. 7illustrates an example method700for performing dynamic haptic retargeting. At block702, a virtual environment is aligned with a physical environment. For example, as described above with reference toFIGS. 1 and 2, virtual reality system125aligns virtual environment202with physical environment204.

At block704, a target virtual object is detected within the virtual environment. For example, virtual target detection module602detects a virtual object that is a target of a user's reach. For example, as described above with reference toFIG. 6, virtual target detection module may use any number of techniques to detect the target virtual object, including, but not limited to, user selection through a user interface or voice command, gaze detection, or analysis of motion of the user's hand.

At block706, a virtual location of the target virtual object is determined. For example, virtual reality system125tracks the location of each virtual object.

At block708, a target physical object is selected within the physical environment. For example, physical target selection module604selects a physical object to be mapped to the target virtual object. For example, as described above with reference toFIG. 6, any number of techniques may be used to select the target physical object. For example, if multiple physical objects are candidates, a physical object closest to the target virtual object may be selected, a physical object that most closely resembles the target virtual object may be selected, or a physical object having a texture represented by the target virtual object may be selected.

At block710, a physical location of the target physical object is determined. For example, virtual reality system126may be configured to maintain location data associated with each physical object in the physical environment to which the virtual environment is mapped.

At block712, it is determined whether or not the virtual location of the target virtual object is aligned with the physical location of the target physical object. For example, warp control module606compares a location of the target virtual object with a location of the target physical object. If the locations are within a threshold distance of one another, then it is determined that the target virtual object and the target physical object are aligned.

If the virtual location of the target virtual object is aligned with the physical location of the target physical object (the “Yes” branch from block712), then at block714, the method ends as there is no need to perform a world warp or a body warp.

On the other hand, if the virtual location of the target virtual object is not aligned with the physical location of the target physical object (the “No” branch from block712), then at block716, a world warp is dynamically applied as the user reaches toward the virtual object.

At block718, warp control module606determines whether or not the virtual location of the target virtual object is aligned with the physical location of the target physical object. For example, warp control module606compares a location of the target virtual object (after the world warp has been applied) with a location of the target physical object. If the locations are within a threshold distance of one another, then it is determined that the target virtual object and the target physical object are aligned.

If the virtual location of the target virtual object is aligned with the physical location of the target physical object (the “Yes” branch from block718), then at block714, the method ends as there is no need to perform a body warp or an additional world warp.

On the other hand, if the virtual location of the target virtual object is not aligned with the physical location of the target physical object (the “No” branch from block718), then at block720, a body warp is dynamically applied as the user reaches toward the virtual object.

Processing continues as described above with reference to block712. In an example implementation, blocks712-720are performed repeatedly as a user reaches toward the target virtual object. These steps may be performed periodically based on a pre-defined time interval. For example, the steps represented by blocks712-720may be performed for each frame of data captured by a sensor120.

FIG. 8illustrates an example method716for dynamically applying a world warp as the user reaches toward a virtual object. At block802, a location difference between the physical location of the target physical object and the virtual location of the target virtual object is calculated. For example, virtual reality system126maintains location data for the target virtual object and the target physical object. In an example implementation, world warp module calculates a difference between the location of the target virtual object and the location of the target physical object. The difference may be represented as a vector, as a degree of rotation, or as a combination of a degree of rotation and a vector, which, when applied to the virtual environment with respect to the physical environment, would result in the target virtual object being aligned with the target physical object.

At block804, a desired world warp is determined based on the location difference. For example, if the location difference is represented as a degree of rotation, a desired world warp is determined to be equal to the location difference. In other words, the desired world warp is a world warp that, if applied to the virtual environment with respect to the physical environment, would result in the target virtual object being aligned with the physical object.

However, as is well known in the art, applying an excessive world warp may be visibly detectable by the user and/or may cause feelings of motion sickness for the user. Previous research has shown that as a user moves his head, translations and/or rotations may be applied to the virtual environment, which are imperceptible or minimally imperceptible to the user. For example, if a user rotates his head 90 degrees to the right, rotating the virtual environment 10 degrees left or right may be imperceptible to the user. Accordingly, threshold factors based on changes in a user's head position (e.g., translation and/or rotation) can be applied to determine a maximum world warp that is likely to be imperceptible to the user. The threshold factors may differ for translation as compared to rotation. Furthermore, the threshold factors may not be symmetric. That is, when a user rotates his head to the right, the threshold for applying a right rotational world warp may be greater than a threshold for applying a left rotational world warp. Similarly, thresholds for applying vertical translations or rotations may differ from thresholds for applying horizontal translations or rotations.

At block806, a first position of a user's head is determined. For example, based on data received from camera114and/or sensors120, a position of the user's head at a first instant in time is determined.

At block808, at a later time, a second position of a user's head is determined. For example, based on data received from camera114and/or sensors120, a position of the user's head at a second, later instant in time is determined. In an example, the difference between the first instant in time and second instant in time is a fraction of a second.

At block810, a position difference between the first and second positions of the user's head is calculated. For example, world warp module608compares the first position of the user's head with the second position of the user's head. The position difference may represent any one or more of a horizontal translation, a vertical translation, a horizontal rotation, or a vertical rotation. In an example implementation, the calculated position difference is a single value that represents a three-dimensional position difference. In another example, the calculated position difference may have multiple components representing, for example, a horizontal translation, a vertical translation, a horizontal rotation, or a vertical rotation.

At block812, a maximum world warp is determined based on the calculated position difference. For example, world warp module608applies a threshold warp factor to the calculated position difference to determine the maximum world warp. In an example implementation, the maximum world warp may be represented as a single value that represents a position change in three-dimensional space. In another example implementation, the maximum world warp may be a combination of multiple values. For example, a first maximum warp value may be based on a horizontal translation of the user's head, a second maximum warp value may be based on a horizontal rotation of the user's head, and a third maximum warp value may be based on a vertical rotation of the user's head.

At block814, it is determined whether or not the desired world warp is less than or equal to the maximum world warp. For example, as described above, the maximum world warp represents a degree to which the virtual environment can be warped while likely being imperceptible to the user. At block814, it is determined whether or not applying a world warp sufficient to align the target virtual object with the target physical object is within the threshold maximum world warp.

If the desired world warp is less than or equal to the maximum world warp (the “Yes” branch from block814), then at block816, the desired world warp is applied. For example, world warp module608rotates and/or translates the virtual environment with respect to the physical environment based on the previously calculated desired world warp, resulting in alignment of the target virtual object and the target physical object.

On the other hand, if the desired world warp is greater than the maximum world warp (the “No” branch from block814), then at block818, the maximum world warp is applied. For example, if it is determined that the world warp necessary to align the target virtual object with the target physical object would likely be perceptible to the user, then then maximum world warp (that is likely to be imperceptible to the user) is applied. For example, world warp module608rotates and/or translates the virtual environment with respect to the physical environment based on the previously calculated maximum world warp. As a result, a location difference between the target virtual object and the target physical object will be less than before the world warp, but the target virtual object and the target physical object will still not be aligned.

FIG. 9illustrates an example method900for calculating a maximum world warp based on horizontal and vertical head rotation. At block902, horizontal and vertical components of the location difference are determined. For example, if both the virtual object and the physical object are resting on a same surface, the horizontal component of the location difference represents the distance between the virtual object and physical object along the plane of the table surface. If the virtual object is, for example, stacked on another virtual object, and the vertical component of the location difference represents the vertical distance between the virtual object and the physical object. If both the virtual object and the physical object are resting on a same surface, the vertical component of the location difference is zero.

At block904, a first head position is determined. For example, a first head position is represented by face906. Block904may correspond to block806inFIG. 8.

At block908, a second head position is determined. For example, a second head position is represented by face910. Block908may correspond to block808inFIG. 8.

At block912, a horizontal rotation difference between the first and second head positions is determined. For example, the difference between face906and face914represents the horizontal rotation difference, which is attributed to left/right head rotation.

At block916, a vertical rotation difference between the first and second head positions is determined. For example, the difference between face906and face918represents the vertical rotation difference, which is attributed to up/down head nodding.

At block920, a maximum horizontal world warp is calculated. For example, world warp module608determines a degree of horizontal rotation represented by the difference between the first and second head positions. A maximum world warp scaling factor is then applied to the degree of horizontal rotation to calculate the maximum horizontal world warp. As described above, based on a horizontal head rotation, two values may be calculated for the maximum world warp (i.e., one for a right rotational warp and one for a left rotational warp). For example, if the user's head rotated toward the right, a first maximum horizontal world warp may be calculated that would allow for the virtual environment to be rotated 49% further to the right and a second maximum horizontal world warp may be calculated that would allow for the virtual environment to be rotated 20% less (effectively rotating the virtual environment to the left).

At block922, a maximum vertical world warp is calculated. For example, world warp module608determines a degree of vertical rotation represented by the difference between the first and second head positions. A maximum world warp scaling factor is then applied to the degree of vertical rotation to calculate the maximum vertical world warp. As described above, based on a vertical head rotation, two values may be calculated for the maximum world warp (i.e., one for an upward rotational warp and one for a downward rotational warp).

FIG. 10illustrates an example method1000for dynamically applying a body warp as a user reaches for a virtual object. At block10002, a physical location of the user's hand is determined. For example, virtual reality system126may track a physical location of the user's hand based on hand tracking device116and/or data from camera114.

At block1004, a virtual location of the virtual representation of the user's hand is determined. For example, virtual reality system126maintains data representing the current location of the virtual representation of the user's hand.

At block1006, a physical location of the physical object is determined. For example, physical target selection module604selects and identifies the target physical object106to which the virtual object108the user is reaching for is mapped. The physical location of the physical object may be tracked, for example, by virtual reality system126

At block1008, a virtual location of the virtual object is determined. For example, virtual reality system126maintains location data corresponding to the virtual location of the virtual object108that the user is reaching for.

At block1010, a body warp is determined by calculating a location difference between the physical location of the physical object and the virtual location of the virtual object. For example, body warp module610calculates a difference between the physical location of the physical object106and the virtual location of the virtual object108.

At block1012, the body warp is applied to the virtual representation of the user's hand. For example, body warp module610translates the virtual representation of the user's hand within the virtual environment, such that a vector describing a path between the physical location of the user's physical hand and the physical location of the physical object has the same distance and direction as a vector describing a path between the translated virtual location of the virtual representation of the user's hand and the virtual location of the virtual object.

FIG. 11illustrates an example incremental body warp. According to the technique described with reference toFIG. 10, a body warp is applied initially, when the user first begins to reach for a virtual object. In contrast,FIG. 11illustrates a scenario in which the body warp is applied incrementally such that as the user's hand gets closer to the target of the reach, a greater body warp is applied.

For example, as illustrated inFIG. 11, POrepresents an initial position1102of the user's physical hand when the user starts to reach for the virtual object1104. VTrepresents the virtual location of the virtual object1104. PTrepresents the physical location of a physical object1106, which is mapped to the virtual object1104. Vector1108, between the physical location of the physical object1106and the virtual location of the virtual object1104, represents the total body warp to be applied to ensure that when the virtual representation of the user's hand reaches the virtual object, the user's physical hand reaches the physical object.

PHrepresents a current location1110of the user's physical hand and VHrepresents a corresponding current location1112of the virtual representation of the user's hand as the user is reaching for the virtual object1104. Vector1114, between the current location of the user's hand the current location of the virtual representation of the user's hand, represents an incremental warp to be applied at the current time, based on the current locations1110and1112.

FIG. 12illustrates an example method1200for dynamically applying an incremental body warp as a user reaches for a virtual object. The method illustrated inFIG. 12may correspond to block720ofFIG. 7.

At block1202, an initial physical location of the user's hand is determined. For example, as illustrated in, and described above with reference toFIG. 11, the initial hand position may be indicated as PO1102as the user begins reaching for the virtual object. As illustrated in, and described above with reference to,FIG. 7, steps712-720are repeated as a user reaches for a virtual object. In an example implementation, POis determined to be the location of the user's physical hand the first time step720is performed for a particular target virtual object. The initial physical location of the user's hand may be tracked by, for example, virtual reality system126, and maintained by body warp module610.

At block1204, a virtual location of the target virtual object is determined. For example, virtual reality system126may maintain location information associated with the virtual object. As illustrated inFIG. 11, the virtual location of the target virtual object may be represented as VT1104.

At block1206, a physical location of the target physical object is determined. For example, physical target selection module604selects and identifies the target physical object1106to which the target virtual object1104the user is reaching for is mapped. The body warp module610determines the location, PT, based, for example, on location data maintained by virtual reality system126.

At block1208, a total body warp is determined. For example, body warp module610calculates a difference between the virtual location, VT, of the target virtual object1104and the physical location, PT, of the target physical object1106.

At block1210, a current physical location of the user's hand is determined. For example, as described above with reference to block1202, an incremental body warp may be applied multiple times as a user reaches for a virtual object. Accordingly, the first time the body warp is applied, the current physical location of the user's hand, PH, is equal to the initial physical location of the user's hand, PO. However, as the user moves their hand, POremains constant, while PHchanges to reflect the current position of the user's hand1110.

At block1212, a first vector is determined between the current physical location of the user's hand and the initial physical location of the user's hand. For example, referring toFIG. 11, body warp module610determines a direction and distance between PHand PO.

At block1214, a second vector is determined between the physical location of the target physical object and the initial physical location of the user's hand. For example, referring toFIG. 11, body warp module610determines a direction and distance between PTand PO.

At block1216, a warping ratio is calculated based on a difference between the first vector and the second vector. For example, body warp module610calculates a warping ratio, α, such that:

At block1218, an incremental body warp is determined based on the total body warp (see block1208) and the warping ratio. For example, body warp module610may multiply the total body warp by the warping ratio to calculate the incremental body warp.

At block1220, the incremental body warp is applied to the virtual representation of the user's hand. For example, the virtual position of the virtual representation of the user's hand1112, is translated by the incremental body warp value.

FIG. 13illustrates an example method1300for applying a body-friendly body warp. As described above with reference toFIG. 4, translating the virtual representation of the user's hand can result in a virtual representation of a hand that appears to be disconnect from the body or otherwise misaligned with the body. Method1300utilizes a rotational adjustment to maintain a more realistic alignment with between the virtual representation of the user's hand and the user's body.

At block1302, an initial virtual hand location is determined. For example, body warp module610determines a location of the virtual representation of the user's hand when the user began reaching for the target virtual object. In an example implementation, this value may remain constant as multiple body warps are applied over time.

At block1304, a current virtual hand location is determined. For example, body warp module610determines a current location of the virtual representation of the user's hand. In an example implementation, as the user reaches for a target virtual object, the location of the virtual representation of the user's hand changes.

At block1306, a virtual location difference is calculated as a difference between the initial virtual hand location and the current virtual hand location. For example, body warp module610determines a vector that represents a direction and a distance between the initial virtual hand location and the current virtual hand location.

At block1308, it is determined whether or not the virtual location difference is greater than a threshold value. For example, a tolerable amount of misalignment between the user's body and the virtual representation of the user's hand may be represented by the threshold value. In an example implementation, the threshold value may include a direction component and a distance component. For example, a greater distance threshold may be tolerable in conjunction with a smaller angle difference.

If the virtual location difference is greater than the threshold (the “Yes” branch from block1308), then at block1310, the warping ratio is applied by applying a translation and a rotation to the virtual representation of the user's hand. For example, body warp module610may translate the virtual representation of the user's hand, and then rotate the virtual representation of the user's hand about a point coinciding with the user's wrist, to better align the portion of the virtual representation of the user's hand that is closest to the user's body.

On the other hand, if the virtual location difference is not greater than the threshold (the “No” branch from block1308), then at block1312, the warping ratio is applied by applying a translation to the virtual representation of the user's hand.

Example Clauses

A. A method comprising: mapping a virtual environment to a physical environment to establish an alignment between the virtual environment and the physical environment; determining, within the physical environment, a physical location of a physical object; determining, within the virtual environment, a virtual location of a virtual object; determining that a user is reaching toward the virtual object; rendering within the virtual environment, a virtual hand that represents at least a portion of the user's hand while the user is reaching toward the virtual object; and based at least in part on a difference between the physical location and the virtual location: dynamically adjusting the alignment between the virtual environment and the physical environment to reduce the difference between the physical location and the virtual location; and dynamically adjusting the virtual representation of the user's hand to cause the user to physically reach for the physical object while it appears that the virtual representation of the user's hand is reaching for the virtual object.

B. A method as Paragraph A recites, further comprising: determining a first position of the user's head while the user is reaching toward the virtual object; determining a second position of the user's head while the user is reaching toward the virtual object; calculating a difference between the first position of the user's head and the second position of the user's head, wherein the difference indicates a vertical rotation; and dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a vertical distance between the physical location and the virtual location.

C. A method as Paragraph A or Paragraph B recites, further comprising: determining a location of the user's physical hand and a corresponding location of the virtual hand while the user is reaching toward the virtual object; determining a virtual vector that represents a distance and direction between the location of the virtual hand and the virtual location of the virtual object; determining a physical vector that represents a distance and direction between the location of the user's physical hand and the physical location of the physical object; and based at least in part on a difference between the virtual vector and the physical vector, dynamically applying a body warping to adjust the location of the virtual hand within the virtual environment.

D. A method as Paragraph C recites, wherein applying the body warping comprises: calculating a warping ratio based on the physical location of the physical object, an initial location of the user's physical hand, and a current location of the user's physical hand; and adjusting the location of the virtual hand within the virtual environment based, at least in part, on the warping ratio.

E. A method as Paragraph C or Paragraph D recites, wherein applying the body warping comprises: applying a translation to the virtual hand to adjust the location of the virtual hand within the virtual environment; and applying a rotation to the virtual hand.

F. A method as any of Paragraphs A-E recite, further comprising: repeatedly applying a world warping as the user reaches toward the virtual object.

G. A method as any of Paragraphs A-F recite, further comprising: repeatedly applying a body warping as the user reaches toward the virtual object such that a position of the virtual hand intersects with the virtual location at substantially the same time that a position of the user's physical hand intersects with the physical location.

H. A method comprising: mapping a virtual environment to a physical environment to establish an alignment between the virtual environment and the physical environment; determining, within the physical environment, a physical location of a physical object and a physical location of a user's physical hand; determining, within the virtual environment, a virtual location of a virtual object and a virtual location of a virtual representation of the user's hand; determining that a user is reaching toward the virtual object; determining that the virtual object and the physical object are not aligned, so that, based on a current trajectory, when the virtual representation of the user's hand reaches the virtual object, the user's physical hand will not reach the physical object; and dynamically adjusting the virtual location of the virtual representation of the user's hand to reduce a difference between a vector between the physical location of the physical object and the physical location of the user's physical hand and a vector between the virtual location of the virtual object and the virtual location of the virtual representation of the user's hand.

I. A method as Paragraph H recites, further comprising: repeatedly adjusting the virtual location of the virtual representation of the user's hand as the user reaches toward the virtual object such that the virtual location of the virtual representation of the user's hand intersects with the virtual location of the virtual object at substantially the same time that the physical location the user's hand intersects with the physical location of the physical object.

J. A method as Paragraph H or Paragraph I recites, wherein dynamically adjusting the virtual location of the virtual representation of the user's hand comprises:

applying a translation to the virtual representation of the user's hand to adjust the virtual location of the virtual representation of the user's hand within the virtual environment; and

applying a rotation to the virtual representation of the user's hand.

K. A method as any of Paragraphs H-J recite, wherein dynamically adjusting the virtual location of the virtual representation of the user's hand comprises:

calculating a warping ratio based on the physical location of the physical object, an initial physical location of the user's hand, and a current physical location of the user's hand; and

adjusting the virtual location of the virtual hand within the virtual environment based, at least in part, on the warping ratio.

L. A method as Paragraph K recites, further comprising: repeatedly calculating a warping ratio and adjusting the virtual location of the virtual representation of the user's hand based, at least in part, on the warping ratio as the user reaches toward the virtual object such that the virtual location of the virtual representation of the user's hand intersects with the virtual location of the virtual object at substantially the same time that the physical location the user's hand intersects with the physical location of the physical object.

M. One or more computer readable media having computer-executable instructions stored thereon, which, when executed by a computing device, cause the computing device to perform operations comprising: mapping a virtual environment to a physical environment to establish an alignment between the virtual environment and the physical environment; determining, within the physical environment, a physical location of a physical object; determining, within the virtual environment, a virtual location of a virtual object; determining that a user is reaching toward the virtual object; dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object; and dynamically adjusting a virtual location of a virtual representation of the user's hand to increase a likelihood that a physical hand of the user will reach the physical location of the physical object at substantially the same time that a virtual representation of the user's hand will reach the virtual location of the virtual object.

N. One or more computer readable media as Paragraph M recites, wherein dynamically adjusting a virtual location of a virtual representation of the user's hand to increase a likelihood that a physical hand of the user will reach the physical location of the physical object at substantially the same time that a virtual representation of the user's hand will reach the virtual location of the virtual object includes: dynamically adjusting a virtual location of a virtual representation of the user's hand to reduce a difference between a vector between the physical location of the physical object and a physical location of the user's physical hand and a vector between the virtual location of the virtual object and a virtual location of the virtual representation of the user's hand.

O. One or more computer readable media as Paragraph M or Paragraph N recites, wherein dynamically adjusting a virtual location of a virtual representation of the user's hand comprises: translating the virtual representation of the user's hand within the virtual environment; and rotating the virtual representation of the user's hand within the virtual environment.

P. One or more computer-readable media as any of Paragraphs M-O recite, wherein dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object comprises: determining a change in a position of the user's head; and dynamically adjusting the alignment between the virtual environment and the physical environment based, at least in part, on the determined change in the position of the user's head.

Q. One or more computer-readable media as Paragraph P recites, wherein dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object further comprises: calculating distance between the physical location of the physical object and the virtual location of the virtual object; and dynamically adjusting the alignment between the virtual environment and the physical environment further based, at least in part, on the distance between the physical location of the physical object and the virtual location of the virtual object.

R. One or more computer-readable media as any of Paragraphs M-Q recite, wherein dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object comprises: determining a change in a position of the user's head; based, at least in part, on the change in the position of the user's head, calculating a maximum adjustment value; and adjusting the alignment between the virtual environment and the physical environment based, at least in part, on the maximum adjustment value.

S. One or more computer-readable media as Paragraph R recites, wherein dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object further comprises: calculating a distance between the physical location of the physical object and the virtual location of the virtual object; and dynamically adjusting the alignment between the virtual environment and the physical environment further based, at least in part, on the distance between the physical location of the physical object and the virtual location of the virtual object.

T. One or more computer-readable media as any of Paragraphs M-Q recite, wherein dynamically adjusting the alignment between the virtual environment and the physical environment to reduce a difference between the physical location of the physical object and the virtual location of the virtual object comprises: calculating a vertical distance between the physical location of the physical object and the virtual location of the virtual object; determining a vertical rotation of the user's head; based on the vertical rotation of the user's head, calculating a maximum adjustment value; and dynamically adjusting a vertical alignment between the virtual environment and the physical environment based, at least in part on the maximum adjustment value and the vertical distance between the physical location of the physical object and the virtual location of the virtual object.

CONCLUSION

Although the techniques have been described in language specific to structural features and/or methodological acts, it is to be understood that the appended claims are not necessarily limited to the features or acts described. Rather, the features and acts are described as example implementations of such techniques.

The operations of the example processes are illustrated in individual blocks and summarized with reference to those blocks. The processes are illustrated as logical flows of blocks, each block of which can represent one or more operations that can be implemented in hardware, software, or a combination thereof. In the context of software, the operations represent computer-executable instructions stored on one or more computer-readable media that, when executed by one or more processors, enable the one or more processors to perform the recited operations. Generally, computer-executable instructions include routines, programs, objects, modules, components, data structures, and the like that perform particular functions or implement particular abstract data types. The order in which the operations are described is not intended to be construed as a limitation, and any number of the described operations can be executed in any order, combined in any order, subdivided into multiple sub-operations, and/or executed in parallel to implement the described processes. The described processes can be performed by resources associated with one or more device112and/or server130such as one or more internal or external CPUs or GPUs, and/or one or more pieces of hardware logic such as FPGAs, DSPs, or other types of accelerators.

All of the methods and processes described above may be embodied in, and fully automated via, specialized computer hardware. Some or all of the methods may alternatively be embodied in software code modules executed by one or more general purpose computers or processors. The code modules may be stored in any type of computer-readable storage medium or other computer storage device.