In a modern Technology CAD (TCAD) simulation environment data exchange between different simulators often remains as unsolved challenge. One natural way of data interchange is to use a file format common to all tools involved in the process flow. This approach, however, lacks the functionality often required between certain steps. First, there is the need to ensure a consistent input-wafer for each individual simulator. Second, depending on the type of process simulation at hand, it must be possible for a certain simulator to operate only on a sub-set of the data contained on a wafer. For instance, for a topography tool like an etching simulator only the geometry and material informations are of concern, whereas data like impurity concentrations and meshes are usually ignored. Problems arise when the etching tool is writing back its results into a file. Since it has no knowledge of other data contained in the input wafer, there is no way for the tool to write a valid wafer-state. This problem can only be solved by merging the newly generated geometry of the etch-step (Fig. 1(b)) with the original input-file(Fig. 1(a)), to create a new consistent wafer-state (Fig. 1(c)). The resulting geometry is automatically regridded (new elements were inserted in this example), and all distributed quantities are transferred onto the new points.