The setVisualPerceptionInformationCallback returns a PerceptionInformation object. This class has five interfaces：
- getDataPackageIndex: used to indicate that MSDK is receiving data packets pushed by the aircraft.
- getAngleInterval: The angle difference between adjacent distance data, i.e. the angle interval.
- getDistances: the array of obstacle distance in horizontal direction.
- getUpwardObstacleDistance: the distance array of the obstacle in upward direction.
- getDownwardObstacleDistance: the obstacle distance array in downward direction.
Assuming that the AngleInterval is 1, then the obstacle distance array is stored according to every interval of one degree, so distances[n] indicates the obstacle information in the n degrees of the drone.
For example, 0 degrees is the front direction of the nose, 90 degrees is the right direction, 180 degrees is the tail direction, so 20 degrees is the left direction.
The distance of 60000 means that you have not detected an obstacle.