Rotation matrix in Eigen

Question

Can I use the Eigen library to get the rotation matrix which rotates vector A to vector B? I have been searching for a while, but cannot find related api.

Answer 1

You first have to construct a quaternion and then convert it to a matrix, for instance:

#include 
using namespace Eigen;

int main() {
  Vector3f A, B;
  Matrix3f R;
  R = Quaternionf().setFromTwoVectors(A,B);
}