PolygonsΒΆ

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 xy-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:

_images/2d_polygons_mesh.png

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]

     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    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 
          }
        } 
      } 
    }