For some simple applications, the possibilities of refinement control using an external file for the definition of some control parameters may be sufficient. Other, more complex applications have the possibility to define own refinement criteria.
It is possible to fix a minimal refinement distance in each direction. This minimal refinement paremeters allow to avoid infinite loops in the case of geometries with infinite complexity or other refinement criteria which require an infinite grid.
The minimal refinement parameters may be different for each direction. The parameter setting
min=value;
is simply an abbreviation for
xmin=value; ymin=value; zmin=value;
The minimal distances between nodes in the grid may be much smaller than the values defined here near the boundary, because the definition of the boundary nodes is independent of these parameters.
These four scalar paramters define some homogeneous refinement around the intersection with boundary faces (fnorm, ftang) and boundary lines (lnorm, ltang). They are the maximal length of an edge resp. rectangle with an intersection with the related boundary (fnorm, lnorm) or of edges resp. rectangles orthogonal to them (ftang, ltang).
These calls allow to define local refinement around a point. An isotropical refinement will be defined by the keyword refine and has following parameters:
refine(v,r,x,fx,y,fy,z,fz);
Anisotropical refinement will be defined by the keywords refineX, refineY, refineZ, refineU, refineV and refineW. The same parameter set is the same. The parameters are: