# Surface refinement#

The user can specify the level of refinement for each surface named in the STL file. Similar to the edges refinement step, the level of refinement represents the number of cells resulting from splitting an original cell by an exponent of $$2$$ (level $$2$$ means $$4$$ cells).

Note

It is very important to note that not adding any surface refinement to the model makes the meshing engine ignore the added geometry altogether and output the background mesh only.

In the above image, the global surface refinements levels for all the surfaces in the surfacemesh_multi file is $$1$$ and $$1$$. However, it is possible to override those values by specifying local levels. In the image, inlet1 and pipe have their own levels which have higher priority than the STL global levels.