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XR_BD_body_tracking

note

Pico has published official documentation for XR_BD_body_tracking extension on 05 Feb 2025 with OpenXR 1.1.45 release. You can see it here. This article also covers Pico's private functions related to body-tracking.

Doesn't require any Android permissions for now.

Functions​

xrCreateBodyTrackerBD​

XrResult xrCreateBodyTrackerBD(
    XrSession session,
    const XrBodyTrackerCreateInfoBD* createInfo,
    XrBodyTrackerBD* bodyTracker);

xrDestroyBodyTrackerBD​

XrResult xrDestroyBodyTrackerBD(
    XrBodyTrackerBD bodyTracker);

xrLocateBodyJointsBD​

XrResult xrLocateBodyJointsBD(
    XrBodyTrackerBD bodyTracker,
    const XrBodyJointsLocateInfoBD* locateInfo,
    XrBodyJointLocationsBD* locations);

xrStartBodyTrackingCalibAppBD​

XrResult xrStartBodyTrackingCalibAppBD(
    XrInstance instance,
    const char* currentPackageName,
    XrCalibAppFlagBD flag);

xrGetBodyTrackingStateBD​

XrResult xrGetBodyTrackingStateBD(
    XrInstance instance,
    XrBodyTrackingStatusCodeBD* statusCode,
    XrBodyTrackingErrorCodeBD* errorCode);

Types​

XrBodyTrackerBD​

typedef struct XrBodyTrackerBD_T* XrBodyTrackerBD;

XrBodyTrackingStatusCodeBD​

typedef enum XrBodyTrackingStatusCodeBD {
    XR_BODYTRACKING_INVALID_BD = 0,
    XR_BODYTRACKING_VALID_BD   = 1,
    XR_BODYTRACKING_LIMITED_BD = 2,
} XrBodyTrackingStatusCodeBD;

XrBodyTrackingErrorCodeBD​

typedef enum XrBodyTrackingErrorCodeBD {
    XR_BT_ERROR_INNER_EXCEPTION_BD                 = 0,
    XR_BT_ERROR_TRACKER_NOT_CALIBRATED_BD          = 1,
    XR_BT_ERROR_TRACKER_NUM_NOT_ENOUGH_BD          = 2,
    XR_BT_ERROR_TRACKER_STATE_NOT_SATISFIED_BD     = 3,
    XR_BT_ERROR_TRACKER_PERSISTENT_INVISIBILITY_BD = 4,
    XR_BT_ERROR_TRACKER_DATA_ERROR_BD              = 5,
    XR_BT_ERROR_USER_CHANGE_BD                     = 6,
    XR_BT_ERROR_TRACKING_POSE_ERROR_BD             = 7,
} XrBodyTrackingErrorCodeBD;

XrCalibAppFlagBD​

typedef enum XrCalibAppFlagBD {
    XR_CALIB_MOTION_TRACKER_1_BD = 0,
    XR_CALIB_MOTION_TRACKER_2_BD = 1,
} XrCalibAppFlagBD;

XrBodyJointSetBD​

#define XR_BODY_JOINT_WITHOUT_ARM_COUNT_BD 16
#define XR_BODY_JOINT_COUNT_BD 24

typedef enum XrBodyJointSetBD {
    XR_BODY_JOINT_SET_DEFAULT_BD          = 0,
    //Low accuracy: 16 joints
    XR_BODY_JOINT_SET_BODY_WITHOUT_ARM_BD = 1,
    //High accuracy: 24 joints
    XR_BODY_JOINT_SET_FULL_BODY_JOINTS_BD = 2, 
    XR_BODY_JOINT_SET_MAX_ENUM_BD         = 0x7FFFFFFF,
} XrBodyJointSetBD;

XrBodyTrackerCreateInfoBD​

typedef struct XrBodyTrackerCreateInfoBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    XrBodyJointSetBD jointSet;
} XrBodyTrackerCreateInfoBD;

const static XrStructureType XR_TYPE_BODY_TRACKER_CREATE_INFO_BD = 1000385001;
  • type must be XR_TYPE_BODY_TRACKER_CREATE_INFO_BD
  • next must be NULL or a valid pointer to the next structure in a structure chain See also: XrBodyTrackerBoneLengthBD
  • bodyJointSet must be a valid XrBodyJointSetBD value

XrBodyTrackerBoneLengthBD​

typedef struct XrBodyTrackerBoneLengthBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    float headLength;
    float neckLength;
    float torsoLength;
    float hipLength;
    float upperLegLength;
    float lowerLegLength;
    float footLength;
    float shoulderLength;
    float upperArmLength;
    float lowerArmLength;
    float handLength;
} XrBodyTrackerBoneLengthBD;

const static XrStructureType XR_TYPE_BODY_TRACKER_BONE_LENGTH_BD = 1000385005;
  • type must be XR_TYPE_BODY_TRACKER_BONE_EXT_BD
  • next must be NULL or a valid pointer to the next structure in a structure chain

XrBodyJointsLocateInfoBD​

typedef struct XrBodyJointsLocateInfoBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    XrSpace baseSpace;
    XrTime time;
} XrBodyJointsLocateInfoBD;

const static XrStructureType XR_TYPE_BODY_JOINTS_LOCATE_INFO_BD = 1000385002;
  • type must be XR_TYPE_BODY_JOINTS_LOCATE_INFO_BD
  • next must be NULL or a valid pointer to the next structure in a structure chain

XrBodyJointLocationBD​

typedef struct XrBodyJointLocationBD {
    XrSpaceLocationFlags locationFlags;
    XrPosef pose;
    float radius;
} XrBodyJointLocationBD;

radius is undeclared by official docs, but decompilation shows that it is used.

XrBodyJointLocationsBD​

typedef struct XrBodyJointLocationsBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    XrBool32 allJointPosesTracked;
    uint32_t jointLocationCount;
    XrBodyJointLocationBD* jointLocations;
} XrBodyJointLocationsBD;

const static XrStructureType XR_TYPE_BODY_JOINT_LOCATIONS_BD = 1000385003;
  • type must be XR_TYPE_BODY_JOINTS_LOCATE_INFO_BD
  • next must be NULL or a valid pointer to the next structure in a structure chain

XrBodyJointVelocityBD​

typedef struct XrBodyJointVelocityBD {
    XrSpaceVelocityFlags velocityFlags;
    XrVector3f linearVelocity;
    XrVector3f angularVelocity;
} XrBodyJointVelocityBD;

XrBodyJointVelocitiesBD​

typedef struct XrBodyJointVelocitiesBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    uint32_t jointCount;
    XrBool32 isActive; //unused
    XrBodyJointVelocityBD* jointVelocities;
} XrBodyJointVelocitiesBD;

const static XrStructureType XR_TYPE_BODY_JOINT_VELOCITIES_BD = 1000385007;

XrSpaceAccelerationFlagsBD​

typedef XrFlags64 XrSpaceAccelerationFlagsBD;

static const XrSpaceAccelerationFlagsBD XR_SPACE_ACCELERATION_LINEAR_VALID_BIT_BD = 0x00000001;
static const XrSpaceAccelerationFlagsBD XR_SPACE_ACCELERATION_ANGULAR_VALID_BIT_BD = 0x00000002;

XrBodyJointAccelerationBD​

typedef struct XrBodyJointAccelerationBD {
    XrSpaceAccelerationFlagsBD accelerationFlags;
    XrVector3f linearAcceleration;
    XrVector3f angularAcceleration;
} XrBodyJointAccelerationBD;

XrBodyJointAccelerationsBD​

typedef struct XrBodyJointAccelerationsBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    uint32_t jointCount;
    XrBool32 isActive; //unused
    XrBodyJointAccelerationBD* jointAccelerations;
} XrBodyJointAccelerationsBD;

const static XrStructureType XR_TYPE_BODY_JOINT_ACCELERATIONS_BD = 1000385008;

XrBodyJointActionBD​

typedef enum XrBodyJointActionBD {
    XR_NONE_ACTION_BD      = 0x00000000,
    XR_TOUCH_GROUND_BD     = 0x00000001,
    XR_KEEP_STATIC_BD      = 0x00000002,
    XR_TOUCH_GROUND_TOE_BD = 0x00000004,
    XR_FOOT_DOWN_ACTION_BD = 0x00000008,
} XrBodyJointActionBD;

XrBodyJointActionsBD​

typedef struct XrBodyJointActionsBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    uint32_t jointCount;
    XrBool32 isActive; //unused
    XrBodyJointActionBD* jointActions;
} XrBodyJointActionsBD;

const static XrStructureType XR_TYPE_BODY_JOINT_ACTIONS_BD = 1000385006;

XrBodyJointGlobalLocationsBD​

typedef struct XrBodyJointGlobalLocationsBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    uint32_t jointCount;
    XrPosef* jointGlobalLocations;
} XrBodyJointGlobalLocationsBD;

const static XrStructureType XR_TYPE_BODY_JOINT_GLOBAL_LOCATIONS_BD = 1000385009;

XrBodyJointBD​

typedef enum XrBodyJointBD {
    XR_BODY_JOINT_PELVIS_BD = 0,
    XR_BODY_JOINT_LEFT_HIP_BD = 1,
    XR_BODY_JOINT_RIGHT_HIP_BD = 2,
    XR_BODY_JOINT_SPINE1_BD = 3,
    XR_BODY_JOINT_LEFT_KNEE_BD = 4,
    XR_BODY_JOINT_RIGHT_KNEE_BD = 5,
    XR_BODY_JOINT_SPINE2_BD = 6,
    XR_BODY_JOINT_LEFT_ANKLE_BD = 7,
    XR_BODY_JOINT_RIGHT_ANKLE_BD = 8,
    XR_BODY_JOINT_SPINE3_BD = 9,
    XR_BODY_JOINT_LEFT_FOOT_BD = 10,
    XR_BODY_JOINT_RIGHT_FOOT_BD = 11,
    XR_BODY_JOINT_NECK_BD = 12,
    XR_BODY_JOINT_LEFT_COLLAR_BD = 13,
    XR_BODY_JOINT_RIGHT_COLLAR_BD = 14,
    XR_BODY_JOINT_HEAD_BD = 15,
    XR_BODY_JOINT_LEFT_SHOULDER_BD = 16,
    XR_BODY_JOINT_RIGHT_SHOULDER_BD = 17,
    XR_BODY_JOINT_LEFT_ELBOW_BD = 18,
    XR_BODY_JOINT_RIGHT_ELBOW_BD = 19,
    XR_BODY_JOINT_LEFT_WRIST_BD = 20,
    XR_BODY_JOINT_RIGHT_WRIST_BD = 21,
    XR_BODY_JOINT_LEFT_HAND_BD = 22,
    XR_BODY_JOINT_RIGHT_HAND_BD = 23,
    XR_BODY_JOINT_COUNT_BD = 24,
    XR_BODY_JOINT_MAX_ENUM_BD = 0x7FFFFFFF,
} XrBodyJointBD;

XrSystemBodyTrackingPropertiesBD​

typedef struct XrSystemBodyTrackingPropertiesBD {
    XrStructureType type;
    void* XR_MAY_ALIAS next;
    XrBool32 supportsBodyTracking;
} XrSystemBodyTrackingPropertiesBD;

const static XrStructureType XR_TYPE_SYSTEM_BODY_TRACKING_PROPERTIES_BD = 1000385004;

Include in next sequence chain for xrGetSystemProperties.

Body joints reference​

Body joints reference