Purpose: Detecting the soft tissue envelope and determining the work space available of the surgical situs during surgery is important for advanced instrument navigation techniques, wound care treatment, augmented reality, and instrument design. Different filtering techniques were evaluated to increase detectability of the soft tissue envelope. Methods: An algorithm was built for a time of flight (TOF) camera which recognizes the boarders of the soft tissue envelope. Different filtering techniques were tested on a dataset of eight surgical siti. Results: By using a median filter, a temporal filter and combining different input information provided by the time of flight camera by a logic operation the proposed algorithm was able to recognize the surgical situs in 73% of the images on average. Conclusions: The use of a TOF camera can introduce a new tool for recognizing the soft tissue envelope of a surgical approach.