COMSOL Learning Center

Learn How to Use COMSOL Multiphysics^® at Your Own Pace

Definitions / Boolean and Adjacent

Create custom selections of geometric entities. Duration: 9:31

When setting up your simulation, you can use selections to represent different parts of your geometry. This can be helpful in many instances, such as when you are specifying materials, applying boundary conditions, customizing the mesh, and more.

In the COMSOL Multiphysics^® software, using Boolean and adjacent selections, you can create customized groups of geometric entities that update automatically when you change your model geometry. All of the following selection types use previously defined selections as input.

Boolean selections include:

Complement Selection — creates selections that are the inverse of one or more selections
Difference Selection — creates selections of entities that are in one selection, but not another
Union Selection — combines two or more selections into a single one
Intersection Selection — creates selections of entities contained in all input selections

If you want to create selections of geometric entities that are touching other selections, use adjacent selections. You also have the option to select exterior or interior entities with this selection type.