To use <em>3D extrusion</em> algorithm you need to assign algorithms
and hypotheses of lower dimension as follows.
+(A sample picture below shows algorithms and hypotheses used to
+mesh a cylinder with prismatic volumes).
+
+\image html prism_needs_hyps.png
\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).</li>
+ (logically) vertical edges of the prism (these edges connect the top and
+ base faces of 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:
<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
-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 face
-only.</li>
-<li> Optionally you can define an 1D sub-mesh on some vertical edges
-of stacked prisms, which will override the global 1D hypothesis mentioned
-above. In the above picture, the vertical division is not equidistant
-on all the length because of a "Number Of Segments" hypothesis with
-Scale Factor=3 assigned to one of edges between the shifted stacks.
+ <li> 1D and 2D algorithms and hypotheses that will be applied for
+ meshing the top and 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
+ 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.)
+ </li>
+ <li> Optionally you can define an 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
+ the highlighted edge.
</li></ul>
-\image html image157.gif "Prism with 3D extrusion meshing"
+\image html image157.gif
-As you can see, the <em>3D extrusion</em> algorithm permits to build
-in the same 3D mesh such elements as hexahedrons, prisms and
-polyhedrons.
+Prism with 3D extrusion meshing. "Vertical" division is different on
+neighbor edges due to local 1D hypotheses assigned.
\sa a sample TUI Script of
\ref tui_prism_3d_algo "Use 3D extrusion meshing algorithm".
