# camera pose from solvePnPRansac using 3d-2d motion estimation in monocular visual odometry

In paper **Visual Odometry Part I**,it said that we can get camera pose using 3d-2d motion estimation for the monocular case(It needs three images).

So, I got Rvec and tvec from function solvePnPRansac using 3d-2d motion estimation.

The question is how can I get camera position and draw its trajectory from Rvec and tvec. The following two formulas are right?

1.Rcur=Rvec * Rcur

2.tcur=tcur+scale*(Rcur * tvec)

Beacuase I find Avi Singh use them in 2d-2d motion estimation.

Is there any paper about monocular visual odometry using 3d-2d motion estimation to recommend.