5 ==========================================
6 Associate a model of blocks to a geometry
7 ==========================================
9 Associate the model to the geometry means that the geometry to mesh is
10 "raw" for this application. In other words, there will be no
11 modification of this geometry end no rebuild of a complete new
12 geometry. However it is possible to complete this geometry by adding
13 new pieces if necessary without any topological operation to link
14 these pieces to the initial geometry. Generally, the geometry to mesh
15 is defined as a set of faces, if these faces are not given under solid
16 form but form logically this solid, it is sufficient for this
19 To associate the model to the geometry, three successive steps are to be followed:
21 1. Mandatory: associate **all the vertices** of the model to the geometry
22 2. If necessary: associate **the needed edges** of the model to the geometry
23 3. If necessary: associate **the needed faces** of the model to the geometry
25 The HexaBlock application enables to follow these three steps
26 independently (see :ref:`assoelemts`). To facilitate the association
27 of the model to the geometry, an alternative way exists: the first two
28 steps above can be replaced by a new stage called association by lines
29 (see :ref:`assolines`).
31 .. image:: _static/association2.PNG
42 Associate the vertices
43 ----------------------
45 This step is essential, all the vertices of the model must be associated to the geometry.
47 There are 4 ways for this association:
49 - associate one vertex "v" of the model to a "vertex" of the shape "s"
52 - associate one vertex "v" of the model to a point of curvilinear
53 abscissa "p" of the "edge" included in the shape "s" of the
56 - associate one vertex "v" of the model to a point of coordinates
57 "u,v" of the "face" included in the shape "s" of the geometry.
59 - associate one vertex "v" of the model to a any point.
62 It is possible to examine the association (vertex of the association
63 model, x-y-z-coordinates of the point of the association geometry).
65 For each vertex, the association is made in three steps:
67 - Choose a vertex of the model to associate.
68 - Choose the way of associating among the 4 possibilities described above.
69 - Specify the point on the geometry, the process depends on the
71 - case of an existing vertex: selection and highlight on the
72 vertices of the geometry solely
73 - case of a point taken on an edge of the geometry: selection
74 and highlight of the edges and of a point on the edge in the
75 process of being selected.
76 - case of a point taken on an face of the geometry: selection
77 and highlight of the faces and of a point on the face in the
78 process of being selected.
79 - case of a new point: ask the coordinates and visualize this
87 This step is optional. An association of every edge is determined
88 automatically before generating the mesh. This automatic process
89 applies four different algorithms in the following order:
91 - the first algorithm determines a wire between the two vertices by
92 taking the shortest way.
93 - if that wire does not exist, then another wire is build in the
95 - compute the normals to the two vertices,
96 - compute the mean normal of the two previous normals,
97 - build the plan passing through the two vertices and this
99 - the sought-after wire is the intersection of the geometry
101 - if the intersection with this plan fails, then another wire
102 "iso-type" is determined between the two vertices and going along
103 the faces of the geometry linking these two vertices,
104 - if this wire still does not exist, then the vertices are linked by a
107 If one of the automatic choices is not appropriate, then the
108 association of the edge of the model to the geometry has to be defined
112 Associate the quadrangles
113 -------------------------
115 This step is optional. The model quadrangles association is
116 automatic. The three cases are processed:
118 - all the geometric faces exist then the nodes are computed on these
120 - the faces do exist but some pieces are missing because of the new
121 edges or vertices, in that case two strategies are deployed:
122 - automatic construction of the missing faces from the contour lines,
123 - or association of new faces build in the geometry,
124 - there are no associated faces to the quadrangle of the model:
125 - only the automatic mesh is used,
126 - if this automatic mesh does not work, then it is possible to
127 associate to the model quadrangle a geometric face build in
130 If one of the automatic choices is not appropriate, then the
131 association of the quadrangle of the model to the geometry has to be
139 The description of this step is:
141 - At the end of this new stage, it is necessary that all points of the
142 model blocks are associated with the vertices of the geometry,
143 - The process is to associate the lines of the model of blocks to
144 vertices and edges of geometry until all points of the model of blocks
146 - When all points of the model of blocks are associated, it is still
147 possible to complete with step 2 above (see :ref:`assoedges`) to
148 finish the association of needed edges.
150 See TUI scripts and GUI part.