DOC: explain the semantics of the precision preference parameters

[modules/smesh.git] / doc / salome / gui / SMESH / input / mesh_preferences.doc

/*!

\page mesh_preferences_page Mesh preferences

In the Mesh module you can set mesh preferences, which can be used right now 
or in later sessions with this module according to the preferences.

<h2>General Preferences</h2>

\image html pref21.png

\anchor automatic_update_pref
- <b>Automatic Update</b>
  - <b>Automatic Update</b> - if activated, the mesh in your
    viewer will be automatically updated after it's computation, depending on
    values of additional preferences specified below.
  - <b>Size limit (elements)</b> - allows specifying the maximum
    number of elements in the resulting mesh for which the automatic updating
    of the presentation is performed. This option affects only
    \ref compute_anchor "Compute" operation. Zero value means "no
    limit". Default value is 500 000 mesh elements. 
  - <b>Incremental limit check</b> - if activated,
    the mesh size limit check is not applied to the total number of
    elements in the resulting mesh, it is applied iteratively to each entity type
    in the following order: 0D elements, edges, faces, volumes, balls.
    At each step the number of entities of a certain type is added to the
    total number of elements computed at the previous step - if the resulting
    number of elements does not exceed the size limit, the entities of
    this type are shown, otherwise the user is warned that some entities are not shown.

\anchor display_mode_pref
- <b>Display mode</b>
  - <b>Default display mode</b> - allows to set Wireframe, Shading, Nodes or Shrink
    \ref display_mode_page "presentation mode" as default.

\anchor quadratic_2d_mode_pref
- <b>Representation of the 2D quadratic elements</b>
  - <b>Default mode of the 2D quadratic elements</b> - allows to
    select either \a Lines or \a Arcs as a default
    \ref quadratic_2d_mode "representation" of 1D and 2D
    \ref adding_quadratic_elements_page "quadratic elements".
  - <b>Maximum Angle</b> - maximum deviation angle used by the
    application to build arcs.

- <b>Quality Controls</b>
  - <b>Display entity</b> - if activated, only currently
    \ref quality_page "controlled" entities are displayed in the
    viewer and other entities are temporarily hidden. For example if you
    activate \ref length_page "Length" quality control, which controls
    the length of mesh segments, then only mesh segments are
    displayed and faces and volumes are hidden. 
  - <b>Use precision</b> - if activated, all quality controls
    will be computed at precision defined by <b>Number of digits after
    point</b> - as integers by default.
\anchor dbl_nodes_tol_pref
  - <b>Double nodes tolerance</b> - defines the maximal distance between two
    mesh nodes, at which they are considered coincident by
    \ref double_nodes_control_page "Double nodes" quality control.
    This value is also used in \ref mesh_quality_info_anchor "Quality Info" 
    tab page of \ref mesh_infos_page dialog.

- <b>Mesh export</b>
\anchor export_auto_groups_pref
  - <b>Automatically create groups for MED export</b> - defines a
    default state of a corresponding check-box in \ref export_auto_groups
    "MED Export" dialog.
\anchor group_export_warning_pref
  - <b>Show warning when exporting group</b> - if activated, a warning is
    displayed when exporting a group.

\anchor show_comp_result_pref
- <b>Mesh computation</b>
  - <b>Show a computation result notification</b> - allows to
    select the notification mode about a \ref compute_anchor "mesh computation" result.
    There are 3 possible modes:
    - <b>Never</b> - not to show the \ref meshing_result_anchor "result dialog" at all;
    - <b>Errors only</b> - the result dialog will be shown if there were
      some errors during a mesh computation;
    - <b>Always</b> - show the result dialog after each mesh
      computation. This is a default mode.

\anchor mesh_information_pref
- <b>Mesh information</b>
  - <b>Mesh element information</b> - allows changing the way 
    \ref mesh_element_info_anchor "mesh element information" is shown:
    - <b>Simple</b> - as a plain text
    - <b>Tree</b> - in a tree-like form
\anchor nb_nodes_limit_pref
  - <b>Automatic nodes compute limit</b> - allows defining the size limit for the
    \ref mesh_addition_info_group_anchor "mesh groups" for which
    the number of underlying nodes is calculated
    automatically. If the group size exceeds the value set in the preferences,
    the user will have to press \em Compute button explicitly. Zero value
    means "no limit". By default the value is set to 100 000 mesh elements.
\anchor auto_control_limit_pref
  - <b>Automatic controls compute limit</b> - allows defining a
    maximal number of mesh elements for which the quality controls
    in the \ref mesh_quality_info_anchor "Quality Information" 
    tab page are calculated automatically. If the number of mesh elements
    exceeds the value set in the preferences, it is necessary to press
    \b Compute button explicitly to calculate a quality measure. Zero value
    means "no limit". By default the value is set to 3 000 mesh
    elements.
\anchor group_detail_info_pref
  - <b>Show details on groups in element information tab</b> - when
    this option is switched off (default), only the names of groups, to which the node
    or element belongs, are shown in the \ref mesh_element_info_anchor "Element Info"
    tab of "Mesh Information" dialog box. If this option is
    switched on, the detailed information on groups is shown.
  - <b>Dump base information</b> - allows dumping base mesh information to the
    file, see \ref dump_mesh_infos "Mesh Information".
  - <b>Dump element information</b> - allows dumping element information to the
    file, see \ref dump_mesh_infos "Mesh Information".
  - <b>Dump additional information</b> - allows dumping additional mesh
    information to the file, see \ref dump_mesh_infos "Mesh Information".
  - <b>Dump controls information</b> - allows dumping quality mesh
    information to the file, see \ref dump_mesh_infos "Mesh Information".

- <b>Automatic Parameters</b>
\anchor diagonal_size_ratio_pref
  - <b>Ratio Bounding Box Diagonal / Max Size</b> - defines the ratio
    between the bounding box of the meshed object and the Max Size of
    segments. It is used as a default value of \ref a1d_meshing_hypo_page
    defining length of segments, especially by 
    \ref max_length_anchor "Max Size" hypothesis.
\anchor nb_segments_pref
  - <b>Default Number of Segments</b> - defines the default number of
    segments in \ref number_of_segments_anchor "Number of Segments"
    hypothesis.

- <b>Mesh loading</b>
  - <b>No mesh loading from study file at hypothesis modification</b> - if
    activated, the mesh data will not be loaded from the study file
    when a hypothesis is modified. This allows saving time by omitting
    loading data of a large mesh that is planned to be recomputed with other parameters.

- <b>Input fields precision</b> - allows to adjust input precision of
  different parameters. The semantics of the precision values is
  described in detail in <em>Using input widgets</em> chapter of GUI
  documentation (Introduction to Salome Platform / Introduction to GUI / 
  Using input widgets). In brief: \b positive precision value is the
  maximum allowed number of digits after the decimal point in the
  fixed-point format; \b nagative precision value is the maximum
  allowed number of significant digits in mantissa in either the
  fixed-point or scientific format.
  - <b>Length precision</b> - allows to adjust input precision of coordinates and dimensions.
  - <b>Angular precision</b> - allows to adjust input precision of angles.
  - <b>Length tolerance precision</b> - allows to adjust input precision of tolerance of coordinates and dimensions.
  - <b>Parametric precision</b> - allows to adjust input precision of parametric values.
  - <b>Area precision</b> - allows to adjust input precision of mesh element area.
  - <b>Volume precision</b> - allows to adjust input precision of mesh element volume.

- <b>Preview</b>
  - <b>Sub-shapes preview chunk size</b> - allows to limit the number
    of previewed sub-shapes shown in the hypotheses creation dialog boxes,
    for example "Reverse Edges" parameter of 
    \ref number_of_segments_anchor "Number of segments" hypothesis.

- <b>Python Dump</b>
  - <b>Historical python dump</b> - allows switching between
    \a Historical and \a Snapshot dump mode:
    - In \a Historical mode, Python Dump script includes all commands
      performed by SMESH engine.
    - In \a Snapshot mode, the commands relating to objects removed
      from the Study as well as the commands not influencing the
      current state of meshes are excluded from the script.

\anchor mesh_tab_preferences
<h2>Mesh Preferences</h2>

\b Mesh tab page contains parameters defining the way the mesh is
displayed in the 3D Viewer.

\image html pref22.png

- <b>Nodes</b> - allows to define default parameters for nodes, which will be applied 
  for a newly created mesh only. Existing meshes can be customized using 
  \ref colors_size_page "Properties dialog box" available from the context menu of a mesh.
  - <b>Color</b> -  allows to select the color of nodes. Click on the
    downward arrow near the colored line to access to the <b>Select Color</b> dialog box.
  - <b>Type of marker</b> - allows to define the shape of nodes.
  - <b>Scale of marker</b> - allows to define the size of nodes.

- <b>Elements</b> - allows to define default parameters for different
  elements, which will be applied to a newly created mesh
  only. Existing meshes can be customized using
  \ref colors_size_page "Properties dialog box" available from the context menu of a mesh.
  - <b>Surface color</b>  - allows to select the surface color of 2D elements
    (seen in Shading mode). Click on the downward arrow near the colored line to access to the
    <b>Select Color</b> dialog box.
  - <b>Back surface color</b> - allows to select the back surface color
    of 2D elements. This is useful to differ 2d elements with
    reversed orientation. Use the slider to select the color generated basing on
    the <b>Surface color</b> by changing its brightness and saturation.
  - <b>Volume color</b> - allows to select the surface color of 3D elements
    (seen in Shading mode).
  - <b>Reversed volume color</b> - allows to select the surface color
    of reversed 3D elements. Use the slider to select the color generated basing on
    the <b>Volume color</b> by changing its brightness and saturation.
  - <b>0D element color</b> - allows to choose color of 0D mesh elements.
  - <b>Ball color</b> - allows to choose color of discrete mesh elements (balls).
  - <b>Outline color</b> - allows to select the color of element borders.
  - <b>Wireframe color</b> - allows to select the color of borders of
    elements in the wireframe mode.
  - <b>Preview color</b> - allows to select the preview color of the
    elements, which is used while 
    \ref adding_nodes_and_elements_page "manual creation of elements".
  - <b>Size of 0D elements</b> - specifies default size of 0D elements.
  - <b>Size of ball elements</b> - specifies default size of discrete
    elements (balls).
  - <b>Scale factor of ball elements</b> - specifies default scale
    factor of discrete elements (balls) allowing to adjust their size in the Viewer.
  - <b>Line width</b> - allows to define the width of 1D elements (segments).
  - <b>Outline width</b> - allows to define the width of borders of
    2D and 3D elements (shown in the Shading mode).
  - <b>Shrink coef.</b> - allows to define relative size of a shrunk
    element compared a non-shrunk element in percents in the shrink mode.

- <b>Groups</b>
  - <b>Names color</b> - specifies color of group names to be used in
    the 3D viewer.
  - <b>Default color</b> - specifies the default group color, which is used 
    to create a new mesh group (see \ref creating_groups_page "Create Group dialog box").

- <b>Numbering</b> allows to define properties of numbering functionality:
  - <b>Nodes</b> - specifies text properties of nodes numbering
    (font family, size, attributes, color).
  - <b>Elements</b> - same for elements.

- <b>Orientation of Faces</b> - allows to define default properties of
  orientation vectors. These preferences will be applied to the newly
  created meshes only; properties of existing meshes can be customized
  using \ref colors_size_page "Properties dialog box" available from
  the context menu of a mesh.
  - \b Color - allows to define the color of orientation vectors;
  - \b Scale - allows to define the size of orientation vectors;
  - <b>3D Vector</b> - allows to choose between 2D planar
    and 3D vectors.

<br><h2>Selection Preferences</h2>

\image html pref23.png

- <b>Selection</b> - performed with mouse-indexing (preselection)
  and left-clicking on an object, whose appearance changes as defined in
  the <b>Preferences</b>.
  - <b>Object color</b> - allows to select the color of mesh (edges and
    borders of meshes) of the selected entity. Click on the colored line
    to access to the <b>Select Color</b> dialog box.
  - <b>Element color</b> - allows to select the color of surface of selected
    elements (seen in Shading mode). Click on the colored line to access
    to the <b>Select Color</b> dialog box.

- <b>Preselection</b> - performed with mouse-indexing on an object,
  whose appearance changes as defined in the <b>Preferences</b>.
  - <b>Highlight color</b> - allows to select the color of mesh (edges and
    borders of meshes) of the entity. Click on the colored line to access
    to the <b>Select Color</b> dialog box.

- <b>Precision</b> - in this menu you can set the value of precision
  used for <b>Nodes</b>, <b>Elements</b> and <b>Objects</b>.

<br><h2>Scalar Bar Preferences</h2>

\image html pref24.png

\note The following settings are default and will be applied to
a newly created mesh only. Existing meshes can be customized using
local \ref scalar_bar_dlg "Scalar Bar Properties dialog box" available
from the context menu of a mesh.

- <b>Font</b> - in this menu you can set type, face and color of
  the font of <b>Title</b> and <b>Labels</b>.

- <b>Colors & Labels</b> - in this menu you can set the <b>number of
  colors</b> and the <b>number of labels</b> in use.

- <b>Orientation</b> - here you can choose between vertical and
  horizontal orientation of the <b>Scalar Bar</b>.

- <b>Origin & Size Vertical & Horizontal</b> - allows to define
  placement (<b>X</b> and <b>Y</b>) and lookout (<b>Width</b> and
  <b>Height</b>) of Scalar Bars.
  - <b>X</b> - abscissa of the point of origin (from the left side).
  - <b>Y</b> - ordinate of the origin of the bar (from the bottom).

- <b>Distribution</b> in this menu you can Show/Hide distribution
  histogram of the values of the <b>Scalar Bar</b> and specify the
  <b>Coloring Type</b> of the histogram:
  - <b>Multicolor</b> - the histogram is colored as <b>Scalar Bar</b>.
  - <b>Monocolor</b> - the histogram is colored as selected with
    <b>Distribution color</b> selector.

*/