Polygons

Learning targets

• Use polygons

The polygon primitive is the most versatile one. It is in principle possible to describe any geometry just by polygons absolutely positioned within the -plane. However, it lies within the responsibility of the user to properly set all the polygon points. The example of this section shows a moderately irregular polygon above two layers:

Since all structures are defined in absolute coordinates, changing the shape of one structure, e.g. the height of the first layer, requires to change all polygon points.

.jcm Input File

• layout.jcm [ASCII]

  Layout2D {
    Name = "TutorialExample2D"
    UnitOfLength = 1e-06
    
    MeshOptions {
      MaximumSideLength = 1.5
    }
    Objects { 
      Polygon { 
        Name = "ComputationalDomain/Background" 
        DomainId = 1 
        Priority = -1 
        Points = [-3 -3, 3 -3, 3 3, 0 3.5, -3 3] 
      } 
      
      Polygon { 
        Name = "Layer1" 
        DomainId = 2 
        Points = [-3 -3, 3 -3, 3 -2, -3 -2] 
      } 
      Polygon { 
        Name = "Layer2" 
        DomainId = 3 
        Points = [-3 -2, 3 -2, 3 -1.5, -3 -1.5] 
      } 
      
      Polygon {  
        Name = "Particle"  
        DomainId = 4
        Points = [0.0 -1.0, 0.5 0.5, 2.0 1.0, 0.5 1.5, 0.0 3.0, -0.5 1.5,  -2.0 1.0,-0.5 0.5]
        MeshOptions {
          MaximumSideLength = 0.6 
        }
      } 
    } 
  }