Preferences

Menu: Utilities->Preferences...

Toolbar:

Preferences

Note: There are many settings in GiD that have a predefined value, but that can be modified by the user. They can be accessed in one of two ways. Firstly, by opening the Preferences window from the Utilities pull-down menu, and secondly via the Variables command in the Utilities section of the Right buttons menu (the latter is also available in the Contextual mouse menu). Almost all the preferences variables are present in the Preferences window, but some advanced ones are only available in Variables command.

In the following section the different options available in the Preferences window are shown and their different settings explained.

Usually variables are graphically set trough the preferences window, but some unusual variables must be set from the lower command line, with this command:

Mescape Utilities Variables <varname> <varvalue>

if <varname> is not specified then the mouse contextual menu (see Mouse operations ) will show the list of available variables.

General

The first group of Preferences are general options, and are used to set the different ways of working with GiD.

General preferences

Variable: CreateAlwaysNewPoint. Respective values: 1,0,-2. Default is 0 (Ask).

Graphical

The second group of preferences are graphical options, and are used to set different ways of visualizing the model. They do not change the geometry or the model information.

Graphical preferences

Variable: DrawSurfaceMode. Default is 1 (Boundary lines).

If this option is set various further options are available, though these only apply when rotating.

Meshing

The third group of preferences are meshing options.

Preferences window

Linear: 3 nodes.

Triangle: 6 nodes.

Quadrilateral: 8 nodes.

Tetrahedra: 10 nodes.

Hexahedra: 20 nodes.

Prisms: 15 nodes.

The different conectivities can be seen at Element type .

GiD can use three kinds of surface mesher.

If any entity has Skip or NoSkip Mesh Criteria (see Mesh criteria ), the surfaces involved are meshed with the Rjump mesher, even if another mesher is set in this window. These mesh generators are based on the advancing front generation mesh technique in order to improve speed and portability. Variable: SurfaceMesher. Values: 0 (Rfast), 1 (Rsurf) and 4 (Rjump). Default is 0 (Rfast).Note: GiD can try another mesher internally when one of them fails to generate the mesh for one surface.

GiD can use two kinds of volume mesher:

Example of size transition if 'Regular transition near boundary' is set.

Example of size transition if 'Regular transition near boundary' is not set.

Variable: BoundaryLayer(GrowLaw). Values: 0 (Function 1), 1 (Function 2) and 2 (Function 3). Default is 0 (Function 1).

The red line below these options shows schematically the difference of heigt of the different layers of boundary layer mesh.

Variable: HighQualitySmoothing. Values: 0 (Normal), 1 (HighAngle) and 2 (HighGeom). Default is 1 (HighAngle).

Variable: ChordalError(ApplyChordalErrorToModel) (values 0,1), ChordalError(RelativeChordalError) (percentage, positive value), ChordalError(MaxChordalError) (positive value: it is a distance) and

ChordalError(MinElemSize) (positive value: it is a distance). Defaults are 0, 0.0, 0.0 and 0.0 (no chordal error criteria applied).

Algorithm:

1 = Optimization radius: iterative, optimizes distances and positions for minimum porosity.

(ref:Carlos Labra, Eugenio Oñate. High-density sphere packing for discrete element method simulations, Communications in Numerical Methods in Engineering 2009)

2 = Predefined porosity: iterative with fixed radius .Experimental.

3 = Radius expansion : iterative, corrects positions and increases radius.

4 = Optimization radius fast: it's 'Optimization radius' with less precision. (Experimental)

5 = Explicit: iterative, radius defined with porosity and optimizes positions.(Experimental)

Max. iterations: Maximum number of iterations for the choosed algorithm.

Advanced preferences:

Main:

MaxIterLocal: Number of iterations for filters.

Tolerance: Tolerance of distance function to terminate the process.

MinRadius: minimum radius Factor ( Minimum radius = MinRadius*UserRadius(size of element/2) ).

MaxRadius: maximum radius Factor (Maximum radius = MaxRadius*UserRadius(size of element/2) ).

DeltaPosition: perturbation of initial position factor ( Maximum perturbation = DeltaPosition*UserSize ).

DeltaRadius: Randomness of initial radius.( Minimum radius = (1-DeltaRadius)*UserRadius; Maximum radius = (1+DeltaRadius)*UserRadius] ).

NOTE: Delta postition & Delta radius: define randomness of generations ex: if both of them equals 0, the generation will be structured.

NOTE: Maximum values recomended for Delta position & Delta radius:

2D: delta position: 0.6; delta radius:0.6

3D: delta position: 0.4; delta radius:0.4

Preprocess: initial generation of spheres with porosity.

Porosity: Value of porosity for preprocess.

Postprocess: correction of final positions.Experimental.

Overlaps: checked permits overlaping between spheres. If not checked corrects radius of the sphere.

Filters:

Filter: Number of global iterations before activate sphere size filter.

Search: Number of gloabal iterations before activate the search of new overlapings between spheres.

SearchType: Type of search: ( 1=SpatialSearch(Tree-based) 2:WeightedDelaunyRemeshing )

ContactFactor: Sphere Neighborhood factor distance( Vecinas si : Distance(sphere1,sphere2) < ContactFactor*(sphere1.Radius+sphere2.Radius) )

NeighborFactor: Penalty factor between overlaped spheres (in optimization algorithm must be 1.0)

FacetFactor: Penalty factor between overlaped sphere wiht a surface (in optimization algorithm must be 1.0).

OverlapFactor: Factor to eliminate sphere with overlaps ( delete sphere if maximum Overlap > OverlapFactor * Sphere radius )

Sphere Main options

Sphere Filter options

Exchange

The fourth group of preferences are geometry exchange (import and export) options.

Exchange preferences

Import options:

Variable: AutoCollapseAfterImport. Default is active (1).

Variable: ImportTolerance. Default is 0.001.

Variable: CollapseIgnoringLayers. Value: 0 (Each layer separately), 1 (Ignoring Layers). Default is 1 (Ignoring Layers).

Variable: IGESCurveOnSurfaceFrom3D. Value: 0 (space parameter definition), 1 (3D space definition). Default is 1 (3D space definition).

Variable: IGESCreateAllInLayerToUse. Value: 0 (IGES entities created in the file layers), 1 (IGES entities created in the current layer to use).

Export options:

Some CADs are not able to read the IGES B-Rep style and then can be interesting to use the alternative style.

Variable: IGESSolidsManifoldBRep. Value: 0 (no B-Rep output style), 1 (B-Rep output stype). Default is 1 (B-Rep output style).

Fonts

The fifth group of preferences deals with the fonts used inside GiD.

Fonts preferences

Format

The sixth group of preferences deals with numerical formats used inside GiD.

Format preferences

Grid

The seventh group of preferences contains grid options (see Grid ).

Grid preferences

Variable: Grid(DrawLabels). Value: 0,1. Default is 0 (no show labels)