Virtual object movement speed curve for virtual and augmented reality display systems
Systems and methods for regulating the speed of movement of virtual objects presented by a wearable system are described. The wearable system may present three-dimensional (3D) virtual content that moves, e.g., laterally across the user's field of view and/or in perceived depth from the user. The speed of the movement may follow the profile of an S-curve, with a gradual increase to a maximum speed, and a subsequent gradual decrease in speed until an end point of the movement is reached. The decrease in speed may be more gradual than the increase in speed. This speed curve may be utilized in the movement of virtual objections for eye-tracking calibration. The wearable system may track the position of a virtual object (an eye-tracking target) which moves with a speed following the S-curve. This speed curve allows for rapid movement of the eye-tracking target, while providing a comfortable viewing experience and high accuracy in determining the initial and final positions of the eye as it tracks the target.
1. A head-mounted display system comprising:
a display configured to present virtual content to a user;
one or more hardware processors in communication with the display, the one or more hardware processors programmed to:
cause the display system to display a virtual object at a first location; and
cause the display system to move the virtual object to a second location at a variable speed based on an S-shaped speed curve,
wherein the variable speed is based on an inverse of a diopter distance between the first location and the second location.
2. A head-mounted display system comprising:
a display configured to present virtual content to a user;
one or more hardware processors in communication with the display, the one or more hardware processors programmed to:
cause the display system to display a virtual object at a first location;
cause the display system to move the virtual object to a second location at a variable speed based on an S-shaped speed curve;
determine a diopter distance between the first location and the second location;
determine a distance between a focal plane of the first location and a focal plane of the second location; and
determine a total time to move the virtual object from the first location to the second location based at least partly on the diopter distance and the distance between the focal plane of the first location and the focal plane of the second location.
3. The head-mounted display system of claim 2 , wherein to determine the total time, the one or more hardware processors is configured to:
determine at least one tracking time associated with at least one eye of the user based on the diopter distance;
determine at least one focus time associated with at least one eye of the user based on the distance between the focal plane of the first location and the focal plane of the second location; and
select a total time from the at least one tracking time and the at least one focus time.
4. The head-mounted display system of claim 3 , wherein the at least one tracking time comprises a time for the at least one eye of the user to move angularly over the diopter distance.
5. The head-mounted display system of claim 3 , wherein the at least one tracking time comprises a tracking time associated with a left eye and a tracking time associated with a right eye.
6. The head-mounted display system of claim 3 , wherein the at least one focus time comprises a time for the at least one eye of the user to focus over the distance between the focal plane of the first location and the focal plane of the second location.
7. The head-mounted display system of claim 3 , wherein the at least one focus time comprises a focus time associated with a left eye and a focus time associated with a right eye.
8. The head-mounted display system of claim 2 , wherein the one or more hardware processors is configured to determine the variable speed based on the total time.
9. The head-mounted display system of claim 2 , wherein the one or more hardware processors is configured to interpolate a position of the virtual object as a function of time based on one or more parameters associated with the total time or the diopter distance.
10. A method of moving virtual content, the method comprising:
causing to display on a display system a virtual object at a first location;
causing the display system to move the virtual object to a second location at a variable speed following an S-shaped speed curve; and
interpolating a position of virtual object as a function of time, wherein interpolating the position of the virtual object as a function of time comprises interpolating an S-curve function with one or more parameters based on a total time or a diopter distance.
11. The method of claim 10 , wherein the one or more parameters comprises a uniform and a non-uniform parameter and wherein the non-uniform parameter is configured to change values at a variable rate associated with one or more Splines curves as a function the uniform parameter.
12. A method of moving virtual content, the method comprising:
causing to display on a display system a virtual object at a first location;
causing the display system to move the virtual object to a second location at a variable speed following an S-shaped speed curve;
determining a diopter distance between the first location and the second location;
determining a distance between a focal plane of the first location and a focal plane of the second location; and
determining a total time to move the virtual object from the first location to the second location based at least partly on the diopter distance and the distance between the focal plane of the first location and the focal plane of the second location.
13. The method of claim 12 , wherein determining the total time comprises:
determining at least one tracking time associated with at least one eye of a user based on the diopter distance, wherein the at least one tracking time comprises a time for the at least one eye of the user to move angularly over the diopter distance;
determining at least one focus time associated with at least one eye of the user based on a focal plane distance, wherein the at least one focus time comprises a time for the at least one eye of the user to focus over the distance between the focal plane of the first location and the focal plane of the second location; and
selecting a total time from the at least one tracking time and the at least one focus time.
14. The method of claim 13 , wherein the variable speed is based on an inverse of the diopter distance.