  The paper describes a novel real-time algorithm for finding 3D geometric
primitives (cylinders, cones and spheres) from 3D range data. In its core, it
performs a fast model fitting with a model update in constant time (O(1)) for
each new data point added to the model. We use a three stage approach.The first
step inspects 1.5D sub spaces, to find ellipses. The next stage uses these
ellipses as input by examining their neighborhood structure to form sets of
candidates for the 3D geometric primitives. Finally, candidate ellipses are
fitted to the geometric primitives. The complexity for point processing is
O(n); additional time of lower order is needed for working on significantly
smaller amount of mid-level objects. This allows the approach to process 30
frames per second on Kinect depth data, which suggests this approach as a
pre-processing step for 3D real-time higher level tasks in robotics, like
tracking or feature based mapping.
