我正在制作类似增强现实应用程序的东西,其中我有一个 OpenGL 场景,无论 iOS 设备如何移动,我都希望它与重力保持一致。我以为我已经通过 CMDeviceMotion.attitude.pitch 设置好了,直到我发现将 iPhone 侧向倾斜会弄乱这个数字。所以我从 pARk* 示例中提取了一些代码,现在我正试图隔离垂直访问周围的旋转。我正在绘制的场景不关心用户面对的是哪个标题,图形将始终绘制在距观察者一定距离的位置。我认为,当我计算出垂直轴旋转分量时,我可以将其反转并将其与旋转矩阵相乘,这样当用户改变航向时保持 OpenGL 数字静止。
这是我的代码:
CMDeviceMotion *d = motionManager.deviceMotion;
if (d != nil) {
CMRotationMatrix r = d.attitude.rotationMatrix;
transformFromCMRotationMatrix(cameraTransform, &r);
mat4f_t projectionCameraTransform;
multiplyMatrixAndMatrix(projectionCameraTransform, projectionTransform, cameraTransform);
GLKMatrix4 rotMatrix = GLKMatrix4Make(projectionCameraTransform[0],
projectionCameraTransform[1],
projectionCameraTransform[2],
projectionCameraTransform[3],
projectionCameraTransform[4],
projectionCameraTransform[5],
projectionCameraTransform[6],
projectionCameraTransform[7],
projectionCameraTransform[8],
projectionCameraTransform[9],
projectionCameraTransform[10],
projectionCameraTransform[11],
projectionCameraTransform[12],
projectionCameraTransform[13],
projectionCameraTransform[14],
projectionCameraTransform[15]);
}
然后我像往常一样在 OpenGL 中使用 rotMatrix。
想法、建议?提前致谢。
*pARk 示例代码在真实空间中设置了几个点,计算出用户的位置和这些点的相对方向,并将它们绘制在屏幕上,使它们看起来漂浮在地平线上指向它们的位置。
最佳答案
我只是根据设备屏幕方向围绕 Z 轴旋转方向。这不是最漂亮的,但它似乎完全符合我的需要,没有去欧拉和返回(因此,避免了体操锁定问题)
GLKMatrix4 deviceMotionAttitudeMatrix;
if (_cmMotionmanager.deviceMotionActive) {
CMDeviceMotion *deviceMotion = _cmMotionmanager.deviceMotion;
// Correct for the rotation matrix not including the screen orientation:
// TODO: Let the device notify me when the orientation changes instead of querying on each update.
UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];
float deviceOrientationRadians = 0.0f;
if (orientation == UIDeviceOrientationLandscapeLeft) {
deviceOrientationRadians = M_PI_2;
}
if (orientation == UIDeviceOrientationLandscapeRight) {
deviceOrientationRadians = -M_PI_2;
}
if (orientation == UIDeviceOrientationPortraitUpsideDown) {
deviceOrientationRadians = M_PI;
}
GLKMatrix4 baseRotation = GLKMatrix4MakeRotation(deviceOrientationRadians, 0.0f, 0.0f, 1.0f);
CMRotationMatrix a = deviceMotion.attitude.rotationMatrix;
deviceMotionAttitudeMatrix
= GLKMatrix4Make(a.m11, a.m21, a.m31, 0.0f,
a.m12, a.m22, a.m32, 0.0f,
a.m13, a.m23, a.m33, 0.0f,
0.0f, 0.0f, 0.0f, 1.0f);
deviceMotionAttitudeMatrix = GLKMatrix4Multiply(baseRotation, deviceMotionAttitudeMatrix);
}
else
{
// Look straight forward (we're probably in the simulator, or a device without a gyro)
deviceMotionAttitudeMatrix = GLKMatrix4MakeRotation(-M_PI_2, 1.0f, 0.0f, 0.0f);
}
关于ios - 从 CoreMotion 的姿态旋转矩阵中分离并移除水平旋转,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/8364664/