如何在C ++Eigen或Qt中从Scipy重复旋转

编程问答 2022-06-10

问题描述

我对Scipy进行了轮换，我想使用Qt库（或者将Eigen作为最后的手段）在C ++中复制它。如何才能做到这一点？我尝试使用QQuaternion :: fromEulerAngles，但是输出是完全不同的Euler角度。你能告诉我如何重复这种旋转吗？

from scipy.spatial.transform import Rotation as R
r = R.from_euler('xyz',[84.8715505575325,-18.6072424802551,106.28342910934],degrees=True)

print(r.as_matrix().transpose())
>>array([[-0.26573263,0.90971132,0.31907911],[ 0.003305,-0.33011727,0.94393414],[ 0.9640411,0.25188866,0.08471633]])

r2 = R.from_euler('XYZ',[90,180,90],degrees=True)
r3 = r2 * r

print(r3.as_euler('xyz',degrees=True))
>> array([ 0.19642533,15.41049032,19.32819967])

解决方法

您可以使用Eigen并轻松地从Euler角度创建旋转对象（请参见https://eigen.tuxfamily.org/dox/group__TutorialGeometry.html#TutorialGeoEulerAngles）。但是，固有/外部系统必须手动处理，并且需要付出更多的努力。

使用C ++ 11和Eigen的development / master分支：

#define _USE_MATH_DEFINES

#include "Eigen/Core"
#include "Eigen/Geometry"
#include <iostream>
#include <math.h>

long double operator"" _deg(long double x ) 
{ 
    return M_PI * x / 180; 
} 

int main()
{
    std::cout.precision(8);

    Eigen::Quaterniond r,r2,r3;

    // 'xyz' - extrinsic rotation -> z*y*x 
    r =  Eigen::AngleAxisd(106.28342910934_deg,Eigen::Vector3d::UnitZ())
        * Eigen::AngleAxisd(-18.6072424802551_deg,Eigen::Vector3d::UnitY())
        * Eigen::AngleAxisd(84.8715505575325_deg,Eigen::Vector3d::UnitX());
    
    std::cout << r.matrix().transpose() << std::endl << std::endl;

    // 'XYZ' - intrinsic rotation -> x*y*z
    r2 = Eigen::AngleAxisd(90.0_deg,Eigen::Vector3d::UnitX())
        * Eigen::AngleAxisd(180.0_deg,Eigen::Vector3d::UnitY())
        * Eigen::AngleAxisd(90.0_deg,Eigen::Vector3d::UnitZ());
    
    r3 = r2 * r;

    // 'xyz' - extrinsic rotation -> z,y,x (reversed to obtain x,z)
    std::cout << (r3.matrix().eulerAngles(2,1,0).reverse() / M_PI) * 180 << std::endl;

    return 1;
}

输出：

 -0.26573263   0.90971132   0.31907911
0.0033050049  -0.33011727   0.94393414
   0.9640411   0.25188866   0.08471633

0.19642533
  15.41049
   19.3282
c++eigenqtqtqtscipyscipy