The system for performing ala operation in a virtual three dimensional space comprises a visualizing system for visualizing the virtual three dimensional space; a 3D position tracking system for marking, in the real three dimensional space, the real space position of the operation to be performed in the virtual three dimensional space; and a means for mapping the position of the real three dimensional space into the virtual three dimensional space and performing the operation in the mapped position. The 3D position tracking system comprises a positioning means provided with at least one signal source; at least two image sensors for detecting the signals emitted by the at least one signal source of the positioning means; and a first means for determining the real space position of the positioning means relative to the image sensors, based oil the signals generated by the image sensors and the spatial location of the image sensors relative to each other.