# Embedded Boundaries

MFIX-Exa uses AMReX’s Embedded Boundaries to represent container walls. This allows MFIX-Exa to simulate a wide range of shapes and boundary conditions using constructive solid geometry. MFIX-Exa also has the capability of locally refining the computational meshes near walls.

Contents:

- Constructing Embedded Boundaries in MFIX-Exa
- Local Mesh Refinement at Walls
- The Level-Set Function