OpenCV_4.2.0/opencv_contrib-4.2.0/modules/rgbd/README.md

RGB-Depth Processing module

Contains a collection of depth processing algorithms:

• Linemod 3D object recognition
• Fast surface normals and 3D plane finding
• 3D visual odometry
• KinectFusion

Note that the KinectFusion algorithm was patented and its use may be restricted by following (but not limited to) list of patents:

• US20120196679A1 Real-Time Camera Tracking Using Depth Maps
• US20120194644A1 Mobile Camera Localization Using Depth Maps
• US20120194516A1 Three-Dimensional Environment Reconstruction
• US8401225B2 Moving object segmentation using depth images

Since OpenCV's license imposes different restrictions on usage please consult a legal before using this algorithm any way.

That's why you need to set the OPENCV_ENABLE_NONFREE option in CMake to use KinectFusion.