|-
| style="width:30px;" | [[File:impenet_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types#Impenetrable Surface | Impenetrable Surface]]
| style="width:250px;" | Ray reflection, ray diffraction
| style="width:250px;" | All solid & surface geometric objects, no curve objects
|-
| style="width:30px;" | [[File:penet_surf_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types#Penetrable Surface | Penetrable Surface]]
| style="width:250px;" | Ray reflection, ray diffraction, ray transmission through thin walls
| style="width:250px;" | All solid & surface geometric objects, no curve objects
|-
| style="width:30px;" | [[File:terrain_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types#Terrain Surface | Terrain Surface]]
| style="width:250px;" | Ray reflection, ray diffraction
| style="width:250px;" | All surface geometric objects, no solid or curve objects
|-
| style="width:30px;" | [[File:penet_vol_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types#Penetrable Volume | Penetrable Volume]]
| style="width:250px;" | Ray reflection, ray diffraction, ray transmission in material media
| style="width:250px;" | All solid geometric objects, no surface or curve objects
|-
| style="width:30px;" | [[File:base_group_icon.png]]
| style="width:150px;" | [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types#Base Location Set | Base Location Set]]
| style="width:250px;" | Either ray generation or ray reception
| style="width:250px;" | Only point objects
|}
Click on each type to learn more about it in the [[Glossary of EM.Cube's Materials , Sources, Devices & Other Physical Object Types]].
Impenetrable surfaces, penetrable surfaces, terrain surfaces and penetrable volumes represent all the objects that obstruct the propagation of electromagnetic waves (rays) in the free space. What differentiates them is the types of physical phenomena that are used to model their interaction with the impinging rays. [[EM.Terrano]] discretizes geometric objects into a number of flat facets. The field intensity, phase and power of the reflected and transmitted rays depend on the material properties of the obstructing facet. The specular surface of a facet can be modeled as a simple homogeneous dielectric half-space or as a multilayer medium. In that respect, all the obstructing objects such as buildings, walls, terrain, etc. behave in a similar way: