This paper addresses the challenging issue of real-time camera localization relative to any object that have texture or not, sharp edges or occluding contours. 3D contour points, dynamically extracted from a CAD model by Analysis-by-Synthesis on the graphics hardware, are combined with a keyframe-based SLAM algorithm to estimate camera poses. Our tracking solution is accurate, robust to sudden motions and to occlusions, as demonstrated on synthetic and real data. This solution is also easy to deploy since it only uses an RGB camera and a CAD model of the object of interest, requires no manual intervention on this model and runs on a consumer tablet at a frequency of 40Hz on a HD video-stream. Videos are available as supplemental material.