Abstract: It is described a method for determining values of geometry parameters of a cone beam computer tomography apparatus, the method comprising: (a) obtaining x-ray projection data captured by the detector from at least three calibration objects arranged at mutually different positions, the x-ray projection data comprising for each calibration object plural projections at different rotation angles; (b) determining for each calibration object a respective ellipse representation from the respective plural projections; (c) performing a random search across candidate values of the geometry parameters for determining the values of the geometry parameters, wherein a cost function depending on the ellipse representations and the geometry parameters is optimized.

Abstract: User interface controller for controlling a computer comprising: a platform, which is designed such that for use it rests parallel to the floor and which is strong enough and large enough that a person can stand on the platform, at least one sensor, which is disposed underneath or inside the platform and which records the person's movement on the platform and converts it into an electronic signal, a controller which receives the sensor's electronic signals and converts them into digital signals which can be processed by the computer such that the movements can be interpreted as a user input.

Abstract: A method is provided for simulating to a workpiece contour by simulating a milling operation, whereby a blank workpiece is modeled by a family of straight lines in three-dimensional space and all straight lines are parallel to the z-axis. A workpiece contour is determined by intersecting the family of straight lines with a virtual milling edge FK according to a predetermined milling path in three-dimensional space, based on the intersecting points of the straight lines of all swept volumes. A surface grid is formed from the obtained set of intersecting points that describes the workpiece contour.

Abstract: A method and system for approximately reproducing the surface of a workpiece should enable the contour of the workpiece to be reconstructed in a particularly simple manner. The invention provides that a starting body, which represents, in whole or in part, the workpiece in a first approximation step, is subdivided into a number of partial volumes, whereby for a reproduction of the workpiece in a second approximation step, the partial volumes are selected for which a step involving an analytical reproduction of the milling volume, which stretches from the milling cutter along a covered milling path, is established.

Abstract: A method is provided for simulating to a workpiece contour by simulating a milling operation, whereby a blank workpiece is modeled by a family of straight lines in three-dimensional space and all straight lines are parallel to the z-axis. A workpiece contour is determined by intersecting the family of straight lines with a virtual milling edge FK according to a predetermined milling path in three-dimensional space, based on the intersecting points of the straight lines of all swept volumes. A surface grid is formed from the obtained set of intersecting points that describes the workpiece contour.