edges. These two faces should be connected by quadrangle "side" faces.
The prism is allowed to have sides composed of several faces. (A prism
-side is a row of faces (or one face) connecting corresponding edges of
-the top and base faces). But there is a limitation that a prism
-side is allowed to be split only vertically as indicated in the
+side is a row of faces (or one face) connecting the corresponding edges of
+the top and base faces). However, a prism
+side can be split only vertically as indicated in the
picture below.
-\image html prism_ok_ko.png
+\image html prism_ok_ko.png "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
-vertically. And the right prism can't be meshed with this
-algorithm because one of the prism sides is split horizontally (a
+extrusion algorithm: it has six sides, two of which are split
+vertically. The right prism cannot be meshed with this
+algorithm because one of the prism sides is split horizontally (the
splitting edge is highlighted).
The algorithm can propagate 2D mesh not only between horizontal
(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.
-\image html prism_stack.png
-In this picture, four neighboring prism stacks, each comprising two prisms,
-are shown. The shown sub-mesh is used by the algorithm to mesh
-all the eight prisms in the stacks.
+\image html prism_stack.png "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 <em>3D extrusion</em> algorithm you need to assign algorithms
-and hypotheses of lower dimension as follows.
+and hypotheses of lower dimensions as follows.
(A sample picture below shows algorithms and hypotheses used to
mesh a cylinder with prismatic volumes).
-\image html prism_needs_hyps.png
+\image html prism_needs_hyps.png
-\b Global algorithms and hypotheses to be chosen at
+The \b Global algorithms and hypotheses to be chosen at
\ref create_mesh_anchor "Creation of a mesh object" are:
<ul>
<li> 1D algorithm and hypothesis that will be applied for meshing
- (logically) vertical edges of the prism (these edges connect the top and
- base faces of prism). In the sample picture above these are
+ (logically) vertical edges of the prism (which connect the top and the
+ base faces of the prism). In the sample picture above these are
"Regular_1D" algorithm and "Nb. Segments_1" hypothesis.</li>
</ul>
-\b Local algorithms and hypotheses to be chosen at
-\ref constructing_submeshes_page "Constructing sub-meshes" are:
+The \b Local algorithms and hypotheses to be chosen at
+\ref constructing_submeshes_page "Construction of sub-meshes" are:
<ul>
<li> 1D and 2D algorithms and hypotheses that will be applied for
- meshing the top and base prism faces. These faces can be meshed
+ meshing the top and the base prism faces. These faces can be meshed
with any type of 2D elements: quadrangles, triangles, polygons or
- their mix. It's enough to define a sub-mesh on either top or base
+ their mix. It is enough to define a sub-mesh on either the top or the base
face. In the sample picture above, "BLSURF" algorithm meshes
"Face_1" base surface with triangles. (1D algorithm is not
- assigned as "BLSURF" does not require divided edges to create 2D mesh.)
+ assigned as "BLSURF" does not require divided edges to create a 2D mesh.)
</li>
- <li> Optionally you can define an 1D sub-mesh on some vertical edges
+ <li> Optionally you can define a 1D sub-mesh on some vertical edges
of stacked prisms, which will override the global 1D hypothesis mentioned
- above. In the picture above the picture of Object Browser, the
- vertical division is not equidistant on all the length because of
- a "Number Of Segments" hypothesis with Scale Factor=3 assigned to
+ above. In the <b>Prism stacks</b> 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.
</li></ul>
-\image html image157.gif
-
-Prism with 3D extrusion meshing. "Vertical" division is different on
-neighbor edges due to local 1D hypotheses assigned.
+\image html image157.gif "Prism with 3D extrusion meshing. Vertical division is different on neighbor edges because a local 1D hypotheses is assigned."
\sa a sample TUI Script of
\ref tui_prism_3d_algo "Use 3D extrusion meshing algorithm".
