Late warping to minimize latency of moving objects
A method for minimizing latency of moving objects in an augmented reality (AR) display device is described. In one aspect, the method includes determining an initial pose of a visual tracking device, identifying an initial location of an object in an image that is generated by an optical sensor of the visual tracking device, the image corresponding to the initial pose of the visual tracking device. rendering virtual content based on the initial pose and the initial location of the object, retrieving an updated pose of the visual tracking device, tracking an updated location of the object in an updated image that corresponds to the updated pose, and applying a time warp transformation to the rendered virtual content based on the updated pose and the updated location of the object to generate transformed virtual content.
1 . A method comprising:
rendering a first layer of virtual content based on a first pose of a visual tracking device and a first location of a first object depicted in a first image generated by an optical sensor of the visual tracking device;
rendering a second layer of virtual content based on the first pose of the visual tracking device and a first location of a second object depicted in the first image;
accessing a second pose of the visual tracking device;
determining a second location of the first object in a second image that corresponds to the second pose;
determining a second location of the second object in the second image;
applying a first time warp transformation to the first layer based on a combination of the second pose and the second location of the first object;
applying a second time warp transformation to the second layer based on a combination of the second pose and the second location of the second object; and
generating transformed virtual content by combining the first layer and the second layer in a single rendered frame.
2 . The method of claim 1 , further comprising:
generating, using an augmented reality application of the visual tracking device, the virtual content;
rendering the virtual content using a rendering engine of a graphical processing unit at the visual tracking device; and
displaying the transformed virtual content in a display of the visual tracking device.
3 . The method of claim 1 , wherein the first object comprises a physical object or a virtual object.
4 . The method of claim 1 , wherein the first object comprises an animated virtual object,
wherein the first location of the first object is based on an animation behavior of the animated virtual object,
wherein the second location of the first object is based on the animation behavior of the animated virtual object and the second pose.
5 . The method of claim 4 , wherein the animation behavior describes a predefined motion path of the animated virtual object.
6 . The method of claim 1 , wherein the first pose of the visual tracking device are based on inertial sensor data of the visual tracking device.
7 . The method of claim 6 , wherein the inertial sensor data comprises angular velocity data of the visual tracking device between the first pose and the second pose.
8 . The method of claim 1 , wherein the first object comprises a first virtual object and the second object comprises a second virtual object,
wherein determining the second location of the first object is based on the second pose and a first animation behavior of the first virtual object,
wherein determining the second location of the second object is based on the second pose and a second animation behavior of the second virtual object.
9 . The method of claim 8 , wherein determining the second location of the first object further comprises accessing a first animation configuration setting of the first virtual object, wherein determining the second location of the second object further comprises accessing a second animation configuration setting of the second virtual object.
10 . The method of claim 1 , further comprising:
determining the first pose of the visual tracking device of an augmented reality device that comprises the optical sensor;
accessing the first image generated by the optical sensor, the first image corresponding to the first pose of the visual tracking device; and
determining the second pose of the visual tracking device, the second pose following the first pose,
wherein the first object is stationary or non-stationary and the second object is non-stationary or stationary.
11 . A computing apparatus comprising:
a processor; and
a memory storing instructions that, when executed by the processor, configure the apparatus to perform operations comprising:
rendering a first layer of virtual content based on a first pose of a visual tracking device and a first location of a first object depicted in a first image generated by an optical sensor of the visual tracking device;
rendering a second layer of virtual content based on the first pose of the visual tracking device and a first location of a second object depicted in the first image;
accessing a second pose of the visual tracking device;
determining a second location of the first object in a second image that corresponds to the second pose;
determining a second location of the second object in the second image;
applying a first time warp transformation to the first layer based on a combination of the second pose and the second location of the first object;
applying a second time warp transformation to the second layer based on a combination of the second pose and the second location of the second object; and
generating transformed virtual content by combining the first layer and the second layer in a single rendered frame.
12 . The computing apparatus of claim 11 , wherein the operations further comprise:
generating, using an augmented reality application of the visual tracking device, the virtual content;
rendering the virtual content using a rendering engine of a graphical processing unit at the visual tracking device; and
displaying the transformed virtual content in a display of the visual tracking device.
13 . The computing apparatus of claim 11 , wherein the first object comprises a physical object or a virtual object.
14 . The computing apparatus of claim 11 , wherein the first object comprises an animated virtual object,
wherein the first location of the first object is based on an animation behavior of the animated virtual object,
wherein the second location of the first object is based on the animation behavior of the animated virtual object and the second pose.
15 . The computing apparatus of claim 14 , wherein the animation behavior describes a predefined motion path of the animated virtual object.
16 . The computing apparatus of claim 11 , wherein the first pose of the visual tracking device are based on inertial sensor data of the visual tracking device.
17 . The computing apparatus of claim 16 , wherein the inertial sensor data comprises angular velocity data of the visual tracking device between the first pose and the second pose.
18 . The computing apparatus of claim 11 , wherein the first object comprises a first virtual object and the second object comprises a second virtual object,
wherein determining the second location of the first object is based on the second pose and a first animation behavior of the first virtual object,
wherein determining the second location of the second object is based on the second pose and a second animation behavior of the second virtual object.
19 . The computing apparatus of claim 18 , wherein determining the second location of the first object further comprises accessing a first animation configuration setting of the first virtual object, wherein determining the second location of the second object further comprises accessing a second animation configuration setting of the second virtual object.
20 . A non-transitory computer-readable storage medium, the computer-readable storage medium including instructions that when executed by a computer, cause the computer to perform operations comprising:
rendering a first layer of virtual content based on a first pose of a visual tracking device and a first location of a first object depicted in a first image generated by an optical sensor of the visual tracking device;
rendering a second layer of virtual content based on the first pose of the visual tracking device and a first location of a second object depicted in the first image;
accessing a second pose of the visual tracking device;
determining a second location of the first object in a second image that corresponds to the second pose;
determining a second location of the second object in the second image;
applying a first time warp transformation to the first layer based on a combination of the second pose and the second location of the first object;
applying a second time warp transformation to the second layer based on a combination of the second pose and the second location of the second object; and
generating transformed virtual content by combining the first layer and the second layer in a single rendered frame.