2014/10/15 下午 10:13:05

iphone Programming Glossary: quaternion

How can I add overlay text on a video, then re-encode it?

http://stackoverflow.com/questions/10190333/how-can-i-add-overlay-text-on-a-video-then-re-encode-it

http://stackoverflow.com/questions/13613239/drifting-yaw-angle-after-moving-fast

yaw angle after moving fast In my current project I ran into trouble regarding the quaternion provided by Core Motion's CMAttitude. I put the iPhone 5 iOS 6.0.1 at a well defined start position. Then I start to move.. If not possible what is the alternative workaround Accelerometer based gravity estimation PS As we are dealing with quaternion based models this is not related to Gimbal Lock EDIT After doing some more measurements it seems clear that only yaw is.. This is definitely the second best solution as it destroys information about the full rotation status contained in a quaternion. I decided to it that way for strategical considerations I think most developers do tilt motion detection with the gravity..

Using quaternion instead of roll, pitch and yaw to track device motion

http://stackoverflow.com/questions/19239482/using-quaternion-instead-of-roll-pitch-and-yaw-to-track-device-motion

quaternion instead of roll pitch and yaw to track device motion Please bear with my long question I am trying to make it as clear.. I have been finding the roll pitch and yaw values as CMQuaternion quat self.motionManager.deviceMotion.attitude.quaternion myRoll radiansToDegrees atan2 2 quat.y quat.w quat.x quat.z 1 2 quat.y quat.y 2 quat.z quat.z myPitch radiansToDegrees atan2.. there is some disparity in the yaw values i searched and could find from here link that yaw pitch and roll from a quaternion you will have the same problem as if you were using just yaw pitch and roll. You have to use quaternions EVERYWHERE in your..

iphone - core motion (relative rotation)

http://stackoverflow.com/questions/5053793/iphone-core-motion-relative-rotation

iPhone - understanding iPhone rotation

http://stackoverflow.com/questions/5170010/iphone-understanding-iphone-rotation

iphone core motion share improve this question Given the case that you can live with delta movements you can use quaternion difference operation. Let's say you have a previous rotation as quaternion called q1 and the current one q2. Then you can.. can live with delta movements you can use quaternion difference operation. Let's say you have a previous rotation as quaternion called q1 and the current one q2. Then you can calculate the delta dQ between them so that q2 q1 dQ is valid. All you have.. some part To get rid of the drifting effect you only need a way to express your last object's real position q1 as a quaternion i.e. coordinates in your app as displayed on the screen. If you use tools like Unity it might be just reading the appropriate..

Using quaternion instead of roll, pitch and yaw to track device motion

http://stackoverflow.com/questions/19239482/using-quaternion-instead-of-roll-pitch-and-yaw-to-track-device-motion

the correct attitude the match flag is shown on screen. I have been finding the roll pitch and yaw values as CMQuaternion quat self.motionManager.deviceMotion.attitude.quaternion myRoll radiansToDegrees atan2 2 quat.y quat.w quat.x quat.z 1 2.. So now i guess i have to code everything again... Please could you be so kind to point me to a sample code for using Quaternion for this purpose Here is the code i am working on In the ViewController.m within the image didFinishSavingWithError self.motionManager.. startDeviceMotionUpdatesToQueue NSOperationQueue mainQueue withHandler ^ CMDeviceMotion motion NSError error CMQuaternion quat self.motionManager.deviceMotion.attitude.quaternion double tempYaw radiansToDegrees asin 2 quat.x quat.y quat.w quat.z..