Standard STL read-only container stuff

These just provide access to the point data in a clean way

This provides unsafe read/write access to internal data. SO(3) is represented by an Eigen::Quaternion (four parameters). When using direct write acces

三点确定一个平面 a(x-x0)+b(y-y0)+c(z-z0)=0 --> ax + by + cz + d = 0 d = -(ax0 + by0 + cz0) 平面通过点（x0,y0,z0）以及垂直于平面的法线（a,b,c）来得到 (a,b,c)^T = vector(AO) cro

* \brief Lifts a point from the image plane to its projective ray * * \param p image coordinates * \param P coordinates of the projective ray */

parameters[0]: Twi parameters[1]: Twj parameters[2]: Tbc */

世界坐标系到相机坐标系下

* Returns whether the node is a leaf node * @return true iff the node is a leaf */

* Returns the length of the island * @return length of island */

It re-normalizes ``unit_quaternion`` to unit length. Note: Because of the class invariant, there is typically no need to call this function directly.

Add a point to the spline, and invalidate it so its recalculated on the next access

featureId cameraId, point