Description
The tools contained in the Resolution frame allow you to adjust the resolution of the connectors to be created based on the characteristics of the underlying database geometry.
The first pull down list in this frame contains two options to define the minimum number of grid points for features in the geometry and is used to seed the surface mesh generation process. It is important to keep in mind that the term "subdivisions" refers to the number of grid points minus 1 and "edge length" refers to the distance between two consecutive grid points. Use the entry field next to the list to specify the numeric value for the selected option:
- Min. Subdivisions: This option is used to explicitly define the minimum number of subdivisions and is the default option with a default value of 2.
- Min. Edge Length: If this option is selected, the minimum subdivisions is computed as the minimum boundary length in the selected database models (see Min Boundary Length in the section on the Geometry Characteristics frame) divided by the edge length specified in the entry field.
Note: When changing between the Min. Subdivisions and Min. Edge Length options (or analogously, between the Max. Subdivisions and Max. Edge Length options described below), the value shown in the entry field is computed considering the minimum boundary length (or maximum model extents) of the selected database models and the value of the previously selected option.
Analogously, the second pull down list in this frame contains two options to define the initial number of grid points for features in the geometry and is used to seed the surface mesh generation process. It is important to keep in mind that the term "subdivisions" refers to the number of grid points minus 1 and "edge length" refers to the distance between two consecutive grid points. Use the entry field next to the list to specify the numeric value for the selected option:
- Max. Subdivisions: If this option is selected, the initial edge length for a feature is computed as the maximum model extents (see Max. Model Extents in the section on the Geometry Characteristics frame) divided by the number of subdivisions specified in the entry field. This is the default option with a default value of 150.
- Max. Edge Length: This option is used to explicitly define the initial edge length for a feature.
Caution: The minimum and maximum subdivisions/edge lengths are used to define the minimum and initial number of grid points for the features in the geometry and seed the surface mesh generation process. Characteristics of the underlying geometry, curvature resolution, goals, and local sizing may cause additional refinement.
The last parameter in this frame, Curvature Resolution (deg), is used by the Automatic Surface Mesh functionality in two ways: to define the maximum angular deviation that drives the resolution of new connectors and to define the maximum turning angle associated with the Angle boundary condition type used by the 2D T-Rex algorithm. This parameter has a default value of 15.0 and it is expressed in degrees. Use the appropriate entry field to specify its numeric value.
Note: Modifying the Curvature Resolution parameter via the entry field in the Resolution frame updates the value used for the Curvature Stretching filter on the Boundaries tab.
For more information on how the maximum angular deviation effectively drives the resolution of connectors and unstructured domains, please review the definition of the Max. Angle parameter in the Curvature and Cells sections respectively.
Additionally, in order to understand the involvement of the T-Rex algorithm and its boundary conditions in the automatic creation of unstructured domains, it is important to note that the Automatic Surface Mesh functionality initially attempts to classify all the edges in the selected database models as one of three types: Curvature, Convex, and Concave. The connectors on Curvature edges are automatically assigned to an Angle T-Rex boundary condition. On the other hand, the connectors on Convex and Concave edges are automatically assigned to a Max. Aspect Ratio T-Rex boundary condition. After this assignment is completed, the T-Rex algorithm uses this information to populate the unstructured domains with anisotropic surface cells accordingly. Those edges in the database model that are not classified will not be affected by the T-Rex algorithm. For more information on how connectors are classified as Curvature, Convex, and Concave and how to define your own edge classifications, please see the section on the Boundaries tab.