core-motion

I'm setting my SceneKit camera to the current CMDeviceMotion attitude using the CMDeviceMotion extension described in this answer : func deviceDidMove(motion: CMDeviceMotion?, error: NSError?) { if let motion = motion { let orientation = motion.gaze(atOrientation: UIApplication.sharedApplication().statusBarOrientation) cameraNode.orientation = orientation } } This works beautifully, however, I'd like to block the rotation (roll) and only allow the camera to turn around (yaw) and pitch. I tried to convert the quaternion back to Euler angles and simply leave roll at 0: cameraNode.eulerAngles =

I need to get a CMSampleBuffer for the OpenGL frame. I'm using this: int s = 1; UIScreen * screen = [UIScreen mainScreen]; if ([screen respondsToSelector:@selector(scale)]){ s = (int)[screen scale]; } const int w = viewController.view.frame.size.width/2; const int h = viewController.view.frame.size.height/2; const NSInteger my_data_length = 4*w*h*s*s; // allocate array and read pixels into it. GLubyte * buffer = malloc(my_data_length); glReadPixels(0, 0, w*s, h*s, GL_RGBA, GL_UNSIGNED_BYTE, buffer); // gl renders "upside down" so swap top to bottom into new array. GLubyte * buffer2 = malloc(my

Is it possible to calculate the difference in height when an iPhone moves using the data from CoreMotion? For example, the initial position of the iPhone is saved, then the iPhone is moved which results in a new position. I am interested in detecting if the height of the iPhone moved from its initial position. I don't need absolute units, just a relative value indicating what percentage the height has changed from its original height. let manager = CMMotionManager() // Save initial attitude var initialAttitude = manager.deviceMotion.attitude if manager.deviceMotionAvailable { manager

I am trying to work with 3D rotations but I don't seem to get the idea how the framework does the calculations. For example I get this data: yaw -1.010544 pitch 0.508249 roll 1.128918 Then I print the corresponding rotation matrix 0.599901 -0.128495 -0.789689 0.740043 0.464230 0.486649 0.304065 -0.876344 0.373584 After reading the API and the wiki, I am pretty sure there must be a general way to create a rotationmatrix out of euler angles. I tried all of these here , no results. Do I miss something, or how is this done? Well, iOS or CoreMotion provides both. RotationMatrix and Euler Angle

I've been researching the new M7 chip's CMMotionActivityManager , for determining whether the user of the device is walking, running, in a car, etc (see Apple Documentation ). This seemed like a great step forward over trying to determine this previous from using LocationManager and accelerometer data only. I notice however that CMMotionActivityManager does not have a cycling activity, which is disappointing, and almost a deal-breaker for complete usage as a new activity manager. Has anyone else found a convenient way to use CMMotionActivityManager with cycling also without having to

I am trying to record the data from the iPhone's accelerometer (my own iPhone 5s) and set a label on the screen to that data using String(format: "%.2f", data) where data is the value for the specific axis I want to record. To do this I set up a CMMotionManager and began recording accelerometer data, and I have a timer that constantly updates the text in the label. However, I am getting an error from Xcode: "fatal error: unexpectedly found nil while unwrapping an Optional value". Here is the relevant code: override func viewDidLoad() { super.viewDidLoad() // Do any additional setup after

I'm unable to receive accelerometer data in the background, despite the seemingly correct solution per this question How Nike+ GPS on iPhone receives accelerometer updates in the background? [_motionManager startAccelerometerUpdatesToQueue:[[NSOperationQueue alloc] init] withHandler:^(CMAccelerometerData *accelerometerData, NSError *error) { dispatch_async(dispatch_get_main_queue(), ^{ NSLog(@"perform"); [(id) self setAcceleration:accelerometerData.acceleration]; [self performSelectorOnMainThread:@selector(update) withObject:nil waitUntilDone:NO]; });}]; perform is logged whenever the app is