Bone indices in Apex Legends Bone Matrix:

• Head: Bone index 8 (or 12 on certain robotic models like Pathfinder / Revenant)
• Neck: Bone index 7
• Chest / Upper Spine: Bone index 5
• Pelvis: Bone index 3
• Left / Right Shoulder: Bone indices 14 / 37
• Left / Right Foot: Bone indices 60 / 65

Vector3 GetApexBonePos(uintptr_t entity, int boneId) {
    uintptr_t boneMatrix = Read<uintptr_t>(entity + OFFSET_BONE_MATRIX);
    Matrix3x4 matrix = Read<Matrix3x4>(boneMatrix + (boneId * sizeof(Matrix3x4)));
    return Vector3(matrix.m[0][3], matrix.m[1][3], matrix.m[2][3]);
}

Using Upper Spine (Bone 5) as default aim target gives maximum hit probability regardless of head glitching.

Clean matrix translation. 3x4 matrix layout matches Source engine standard.