Changes

=== Penetrable Surfaces For Indoor Scenes ===

A typical indoor propagation scene usually involves an arrangement of walls that represent the interior of a building. The transmitters and receivers are then placed in the spaces among such walls. From the point of view of EM.Cube's SBR simulator, walls act like thin penetrable surfaces. EM.Cube uses the "Thin Wall Approximation" to model penetrable surfaces. It assumes that rays simply penetrate a wall and exit at the same specular point on the opposite side of the wall. In other words, rays are not displaced by the walls, nor do they get trapped inside the walls (no internal reflection). This is equivalent to assuming a zero thickness for penetrable surfaces for the purpose of geometrical ray tracing, while the finite thickness of the "thin" surface is used for electromagnetic calculation of transmission coefficient. EM.Cube offers "Penetrable Surface Blocks" for the construction of rooms in indoor propagation scenes as well as modeling of hollow buildings and other structures. You can define many penetrable surface groups with arbitrary thicknesses and material properties (color, texture, permittivity and electric conductivity).

# By default, a brick wall with a thickness of 0.5 units is assumed. You can change the '''Thickness''' of the penetrable surface as well as its '''Permittivity''' ε_r and '''Electric Conductivity''' σ.

# Click the '''OK''' button of the dialog to accept the changes and close it.

Under a penetrable surface group, you can draw any of EM.Cube's native solid or [[Surface Objects|surface objects]] or you can import external model files like STEP, IGES or STL. You can change the properties of a penetrable surface group including its default thickness. In the property dialog of the surface group, click on the table that list the properties to select and highlight a row. Then, click the '''Add/Edit''' button to open up the "Edit Layer" dialog. Similar to the case of impenetrable surfaces, from this dialog, you can change the material properties (permittivity and electric conductivity) as well as '''Thickness''', which is expressed in the project units. You can also use EM.Cube's Material List, which will be explained later.