Nonfree module is missing in OpenCV 3.0

with opencv3.0, SURF/SIFT and some other things have been moved to a seperate opencv_contrib repo .

you will have to download that, add it to your main opencv cmake settings (please look at the readme there), and rerun cmake/make.

then:

#include "opencv2/xfeatures2d.hpp"

...
Ptr<SIFT> sift = cv::xfeatures2d::SIFT::create(...);
sift->detect(...);