通给给定旋转轴向量v，旋转角度ang，计算出旋转矩阵

chai3d中通过计算旋转轴和角度来获得旋转矩阵Matrix3

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inline bool rotateAboutLocalAxisRad(const cVector3d& a_axis,

const double& a_angleRad)

{

// compute length of axis vector

double length = a_axis.length();

// check length of axis vector

if (length < C_TINY)

{

// rotation matrix could not be computed because axis vector is not defined

return (false);

}

// normalize axis vector

double f = 1.0 / length;

double x = f * a_axis(0);

double y = f * a_axis(1);

double z = f * a_axis(2);

// compute rotation matrix

double c = ::cos(a_angleRad);

double s = ::sin(a_angleRad);

double v = 1-c;

cMatrix3d m;

m(0,0) = x*x*v+c; m(0,1) = x*y*v-z*s; m(0,2) = x*z*v+y*s;

m(1,0) = x*y*v+z*s; m(1,1) = y*y*v+c; m(1,2) = y*z*v-x*s;

m(2,0) = x*z*v-y*s; m(2,1) = y*z*v+x*s; m(2,2) = z*z*v+c;

(*this) = (*this)*m;

// return success

return (true);

}

上面的函数中的绕任意轴旋转获得的旋转矩阵的算法实现思路如下：

根据Goldman给出的公式进行计算，这个公式有点复杂：



具体推导过程可以参考：

http://www.cppblog.com/lovedday/archive/2008/01/12/41031.html

/article/5766409.html