swift – SceneKit – 获取相机的方向

你能做到的另一种方式就是这个项目是如何做到的：

// Credit to https://github.com/farice/ARShooter

func getUserVector() -> (SCNVector3,SCNVector3) { // (direction,position)
        if let frame = self.sceneView.session.currentFrame {
            let mat = SCNMatrix4(frame.camera.transform) // 4x4 transform matrix describing camera in world space
            let dir = SCNVector3(-1 * mat.m31,-1 * mat.m32,-1 * mat.m33) // orientation of camera in world space
            let pos = SCNVector3(mat.m41,mat.m42,mat.m43) // LOCATIOn of camera in world space

            return (dir,pos)
        }
        return (SCNVector3(0,-1),SCNVector3(0,-0.2))
    }