/*!

\page measurements_page Measurements

Mesh module provides the possibility to perform different measurements
of the selected mesh data.

All measurement operations are available via \b Measurements
top-level menu. Access to the measurements operations is
implemented via a single dialog box, where each operation is represented
as a separate tab page.

\section min_distance_anchor Minimum Distance

This operation allows measuring the distance between two objects.
Currently only node-to-node and node-to-origin operations are
available, but this operation will be extended in the future to support
other mesh objects - elements, meshes, sub-meshes and groups.

To start <b>Minimum Distance</b> operation, select <b>Minimum Distance</b>
item from \b Measurements menu.

\image html min_distance.png

In the dialog box choose the first target and the second target mode by
switching the corresponding radio buttons, then select the objects the distance
between which is to be calculated (or input their IDs directly 
in case of nodes/elements) and press \em Compute button.

The following types of targets are supported:
- \em Node: single mesh node;
- \em Element: single mesh element (not available in this version);
- \em Object: mesh, sub-mesh or group object (not available in this
version);
- \em Origin: origin of the global co-ordinate system.

The result will
be shown in the bottom area of the dialog box. In addition, a simple
preview will be shown in the 3D viewer.

\image html min_distance_preview.png

\section bounding_box_anchor Bounding Box

This operation allows to calculate the bounding box of the selected
object(s).

To start <b>Bounding Box</b> operation, select <b>Bounding Box</b>
item from \b Measurements menu.

\image html bnd_box.png

In the dialog box choose the required type of the object by switching the
corresponding radio button, select the object(s) and press \em Compute button.

The following types of input are available:
- \em Objects: select one or several mesh, sub-mesh or group objects;
- \em Nodes: select a set of mesh nodes;
- \em Elements: select a set of mesh elements.

The result of calculation will be shown in the bottom area of the
dialog box. In addition, a simple preview will be shown in the 3D
viewer.

\image html bnd_box_preview.png

\section basic_properties_anchor Basic Properties

This operation allows calculation of length, area or volume for the the selected
object:
- Length is calculated as a sum of length of all 1D elements;
- Area id a sum of area of all 2D elements
- Volume is a sum of volume of all 3D elements. 

To start one of <b>Basic Properties</b> calculations, select <b>Length</b>, <b>Area</b> 
or <b>Volume</b> item from <b>Measurements - Basic Properties</b> menu.

\image html basic_props.png

In the dialog box select the required type of calculation (length, area or volume), select
the the object (mesh, sub-mesh or group) and press \em Compute button.

The result of calculation will be shown in the bottom area of the
dialog box.

\note
- If mesh consists of 3D elements only, its "length" and "area" will be 0.
- As calculation result is a sum of length, area and volume of all mesh elements,
  duplications are not taken into account; i.e. all duplicated elements
  (elements built on the same set of nodes) will be included into the result.
- Similarly, intersection of elements is not taken into account.

<b>See Also</b> a sample TUI Script of a 
\ref tui_measurements_page "Measurement operations".

*/