Method for controlling view angle, host, and computer readable storage medium

1 . A method for controlling a view angle of a visual content, executed by a host, comprising:

providing, by the host, the visual content, wherein the visual content has a field of view (FOV) corresponding to a first view angle;

in response to determining that a preparation gesture is detected, displaying, by the host, a visual cue in the visual content, wherein the visual cue indicates a first direction; and

in response to determining that the preparation gesture has been changed to a first gesture corresponding to the first direction, adjusting, by the host, the FOV to correspond to a second view angle based on the first direction,

wherein the preparation gesture comprises a hand gesture including a first finger and a second finger that are separated from each other, and

wherein the determining that the preparation gesture has been changed to the first gesture corresponding to the first direction comprises:

in response to determining that a distance between fingertips of the first finger and the second finger is gradually reduced to substantially zero such that the fingertips touch each other, determining that a pinch part of the first gesture is detected, and

in response to determining that, after the hand gesture moved toward the same direction as the first direction indicated by the visual cue while maintaining the pinch part of the first gesture, the fingertips of the first finger and the second finger are separated, determining that a release part of the first gesture is detected, wherein the FOV is adjusted in response to the detection of the release part of the first gesture.

2 . The method according to claim 1 , further comprising:

tracking the hand gesture of a user of the host; and

in response to determining that the hand gesture satisfies a predetermined condition, determining that the preparation gesture is detected.

3 . The method according to claim 2 , further comprises:

determining a first angle between the first finger and a reference axis and determining a second angle between the second finger and the reference axis;

in response to determining that the first angle and the second angle are within a predetermined angle range, determining that the hand gesture satisfies the predetermined condition.

4 . The method according to claim 2 , wherein the hand gesture comprises a palm, and the method further comprises:

in response to determining that the palm is within a predetermined sub-range in the FOV, determining that the hand gesture satisfies the predetermined condition.

5 . The method according to claim 1 , wherein the visual cue comprises a first directional indicator indicating the first direction.

6 . The method according to claim 5 , wherein the visual cue further comprises a second directional indicator indicating a second direction, wherein the second direction is different from the first direction.

7 . The method according to claim 5 , wherein the visual cue further comprises a reference object, and the method further comprises:

varying an appearance of the reference object in a process of the preparation gesture being changed to the first gesture corresponding to the first direction.

8 . The method according to claim 7 , wherein varying the appearance of the reference object in the process of the preparation gesture being changed to the first gesture corresponding to the first direction comprises:

reducing a size of the reference object in the process of the preparation gesture being changed to the first gesture corresponding to the first direction.

9 . The method according to claim 7 , wherein varying the appearance of the reference object in the process of the preparation gesture being changed to the first gesture corresponding to the first direction comprises:

changing a color of the reference object in the process of the preparation gesture being changed to the first gesture corresponding to the first direction.

10 . The method according to claim 5 , wherein the visual cue further comprises a reference object, and the method further comprises:

moving the reference object toward the first direction in the process of the preparation gesture being changed to the first gesture corresponding to the first direction.

11 . The method according to claim 1 , wherein the first gesture corresponding to the first direction is a pinch gesture moving toward the first direction for more than a predetermined time length or a predetermined distance.

12 . The method according to claim 1 , wherein after adjusting the FOV to correspond to the second view angle based on the first direction, the method further comprises:

in response to determining that the first gesture corresponding to the first direction is maintained, maintaining the visual cue and adjusting the FOV to correspond to a third view angle based on the first direction.

13 . The method according to claim 1 , wherein a difference between the first view angle and the second view angle is a predetermined angle.

14 . The method according to claim 1 , wherein adjusting the FOV to correspond to the second view angle based on the first direction comprises:

turning the FOV corresponding to the first view angle to the first direction by a predetermined angle.

15 . The method according to claim 1 , wherein the visual content shows a virtual reality world provided by the host.

16 . The method according to claim 15 , wherein the virtual reality world comprises an avatar corresponding to a user of the host and facing the first view angle, and adjusting the FOV to correspond to the second view angle based on the first direction comprises:

turning the avatar facing the first view angle to the first direction to face the second view angle.

17 . The method according to claim 1 , wherein the visual content comprises a hand object corresponding to the hand gesture tracked by the host.

18 . A host, comprising:

a non-transitory storage circuit, storing a program code; and

a processor, coupled to the non-transitory storage circuit and accessing the program code to perform:

providing a visual content, wherein the visual content has a field of view (FOV) corresponding to a first view angle;

in response to determining that a preparation gesture is detected, displaying a visual cue in the visual content, wherein the visual cue indicates a first direction; and

in response to determining that the preparation gesture has been changed to a first gesture corresponding to the first direction, adjusting the FOV to correspond to a second view angle based on the first direction,

wherein the preparation gesture comprises a hand gesture including a first finger and a second finger that are separated from each other, and

wherein the determining that the preparation gesture has been changed to the first gesture corresponding to the first direction comprises:

in response to determining that a distance between fingertips of the first finger and the second finger is gradually reduced to substantially zero such that the fingertips touch each other, determining that a pinch part of the first gesture is detected, and

in response to determining that, after the hand gesture moved toward the same direction as the first direction indicated by the visual cue while maintaining the pinch part of the first gesture, the fingertips of the first finger and the second finger are separated, determining that a release part of the first gesture is detected, wherein the FOV is adjusted in response to the detection of the release part of the first gesture.

19 . A non-transitory computer readable storage medium, the computer readable storage medium recording an executable computer program, the executable computer program being loaded by a host to perform steps of:

providing a visual content, wherein the visual content has a field of view (FOV) corresponding to a first view angle;

in response to determining that a preparation gesture is detected, displaying a visual cue in the visual content, wherein the visual cue indicates a first direction; and

in response to determining that the preparation gesture has been changed to a first gesture corresponding to the first direction, adjusting the FOV to correspond to a second view angle based on the first direction,

wherein the preparation gesture comprises a hand gesture including a first finger and a second finger that are separated from each other, and

wherein the determining that the preparation gesture has been changed to the first gesture corresponding to the first direction comprises:

in response to determining that a distance between fingertips of the first finger and the second finger is gradually reduced to substantially zero such that the fingertips touch each other, determining that a pinch part of the first gesture is detected, and

in response to determining that, after the hand gesture moved toward the same direction as the first direction indicated by the visual cue while maintaining the pinch part of the first gesture, the fingertips of the first finger and the second finger are separated, determining that a release part of the first gesture is detected, wherein the FOV is adjusted in response to the detection of the release part of the first gesture.