:align: center
.. centered::
- "Clipping view of a mesh of a prism with non-planar base and top faces"
+ Clipping view of a mesh of a prism with non-planar base and top faces
The prism is allowed to have sides composed of several faces. (A prism
side is a row of faces (or one face) connecting the corresponding edges of
:align: center
.. centered::
- "A suitable and an unsuitable prism"
+ A suitable and an unsuitable prism
In this picture, the left prism is suitable for meshing with 3D
extrusion algorithm: it has six sides, two of which are split
(i.e. base and top) faces of one prism but also between faces of prisms
organized in a stack and between stacks sharing prism sides.
+.. _prism_stacks:
+
.. image:: ../images/prism_stack.png
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.. centered::
- "Prism stacks"
+ Prism stacks
This picture shows four neighboring prism stacks, each comprising two prisms.
The shown sub-mesh is used by the algorithm to mesh
all eight prisms in the stacks.
-To use **Extrusion 3D** algorithm you need to assign algorithms
+To use *Extrusion 3D* algorithm you need to assign algorithms
and hypotheses of lower dimensions as follows.
(A sample picture below shows algorithms and hypotheses used to
mesh a cylinder with prismatic volumes).
The **Local** algorithms and hypotheses to be chosen at
:ref:`constructing_submeshes_page` are:
-* 1D and 2D algorithms and hypotheses that will be applied for meshing the top and the base prism :ref:`submesh_shape_section`. These faces can be meshed with any type of 2D elements: quadrangles, triangles, polygons or their mix. It is enough to define a sub-mesh on either the top or the base face. In the sample picture above, "NETGEN_1D2D" algorithm meshes "bottom disk" face with triangles. (1D algorithm is not assigned as "NETGEN_1D2D" does not require divided edges to create a 2D mesh.)
+* 1D and 2D algorithms and hypotheses that will be applied for meshing the top and the base prism :ref:`faces <submesh_shape_section>`. These faces can be meshed with any type of 2D elements: quadrangles, triangles, polygons or their mix. It is enough to define a sub-mesh on either the top or the base face. In the sample picture above, "NETGEN_1D2D" algorithm meshes "bottom disk" face with triangles. (1D algorithm is not assigned as "NETGEN_1D2D" does not require divided edges to create a 2D mesh.)
-* Optionally you can define a 1D sub-mesh on some vertical :ref:`submesh_shape_section` of stacked prisms, which will override the global 1D hypothesis mentioned above. In the **Prism stacks** picture, the vertical division is not equidistant on the whole length because a "Number Of Segments" hypothesis with Scale Factor=3 is assigned to the highlighted edge.
+* Optionally you can define a 1D sub-mesh on some vertical :ref:`edges <submesh_shape_section>` of stacked prisms, which will override the global 1D hypothesis mentioned above. In the :ref:`Prism stacks <prism_stacks>` picture, the vertical division is not equidistant on the whole length because a "Number Of Segments" hypothesis with Scale Factor=3 is assigned to the highlighted edge.
-If **Extrusion 3D** algorithm is assigned to a sub-mesh in a mesh
+If *Extrusion 3D* algorithm is assigned to a sub-mesh in a mesh
with multiple sub-meshes, the described above approach may not work as
expected. For example the bottom face may be meshed by other algorithm
-before **Extrusion 3D** have a chance to project a mesh from the
+before *Extrusion 3D* have a chance to project a mesh from the
base face. This thing can happen with vertical edges as well. All
these can lead to either a meshing failure or to an incorrect meshing.
-
In such a case, it's necessary to explicitly define algorithms
-that **Extrusion 3D** implicitly applies in a simple case:
+that *Extrusion 3D* implicitly applies in a simple case:
* assign :ref:`projection_1D2D` algorithm to the top face and
* assign a 1D algorithm to a group of all vertical edges.
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.. centered::
- "Prism with Extrusion 3D meshing. Vertical division is different on neighbor edges because several local 1D hypotheses are assigned."
+ Prism with Extrusion 3D meshing. Vertical division is different on neighbor edges because several local 1D hypotheses are assigned
-**See Also** a sample TUI Script of
-:ref:`tui_prism_3d_algo`.
+**See Also** a sample TUI Script of :ref:`tui_prism_3d_algo`.
