.. role:: blue
   :class: blue

Surface Area Calculation
========================
.. _Calculation_of_Surface_Area_:

.. версия ядра: 

The method

.. code-block:: cpp

   double CalculateArea( const RPArray<MbFace> & faces,
                               double            deviateAngle )

calculates the surface area of a set of faces.

The input parameters of the method are:

- **faces** – a set of faces
- *deviateAngle* – a parameter that controls the calculation accuracy

The method returns the area of the set of faces.

The method is declared in the *mip_solid_mass_inertial.h* file.

The *deviateAngle* parameter controls the calculation accuracy, and the computation time depends on its value. The *deviateAngle* parameter must be within the range 0.01 <= *deviateAngle* <= 0.35 radians. In the general case, the calculation is performed numerically and uses triangulation of the parameter domain of face surfaces. Triangulation of the parametric domain of faces is performed by the :blue:`CalculateGrid`\() method described in subsection :ref:`Constructing polygons for an object <Constructing_Polygons_for_an_Object_>`, with *stepData*.\ *stepType* = ist_MipStep and *stepData.angle* = *deviateAngle*. The *deviateAngle* parameter defines the maximum allowable angle between normals of adjacent triangles and quadrilaterals of the surface triangulation.

The method

.. code-block:: cpp

   double CalculateArea( const MbFace & face,
                               double   deviateAngle )

calculates the surface area of a single face.

The input parameters of the method are:

- **face** – a face
- *deviateAngle* – a parameter that controls the calculation accuracy

The method returns the area of the **face** face.

The method is declared in the *tri_face.h* file.

The *deviateAngle* parameter controls the calculation accuracy, and the computation time depends on its value. The *deviateAngle* parameter must be within the range 0.01 <= *deviateAngle* <= 0.35 radians.

The method

.. code-block:: cpp

   double CalculateArea( const MbSurface & surface,
                               double      deviateAngle )

calculates the surface area.

The input parameters of the method are:

- **surface** – a surface
- *deviateAngle* – a parameter that controls the calculation accuracy

The method returns the area of the **surface** surface.

The method is declared in the *mip_solid_area_volume.h* file.

The *deviateAngle* parameter controls the calculation accuracy, and the computation time depends on its value. The *deviateAngle* parameter must be within the range 0.01 <= *deviateAngle* <= 0.35 radians.

The method

.. code-block:: cpp

   double CalculateAreaCentre( const MbFace &        face,
                                     double          deviateAngle,
                                     bool            byOuter,
                                     VERSION         version,
                                     MbCartPoint3D & centre )

calculates the surface area and the center of mass of a face.

The input parameters of the method are:

- **face** – a face
- **deviateAngle** – a parameter that controls the calculation accuracy
- **byOuter** – a parameter that ignores inner cuts of the face
- **version** – a parameter that controls calculation versioning

The output parameter of the method is **centre**, the center of mass of the face.

The method returns the area of the face.

The method is declared in the *mip_solid_area_volume.h* file.

The *deviateAngle* parameter controls the calculation accuracy, and the computation time depends on its value. The *deviateAngle* parameter must be within the range 0.01 <= *deviateAngle* <= 0.35 radians.

The *byOuter* parameter allows excluding inner cuts of the face from the calculation. If *byOuter* = true, the calculation assumes that inner cuts of the face are absent. For a normal calculation of the surface area and the center of mass of a face, *byOuter* should be set to false. The version parameter is required to support old calculation versions.

The method

.. code-block:: cpp

   double CalculateAreaCentre( const MbFaceShell &     shell,
                                     double            deviateAngle,
                                     MbCartPoint3D &   centre )

calculates the surface area and the center of mass of a set of faces.

The input parameters of the method are:

- **shell** – a set of faces
- *deviateAngle* – a parameter that controls the calculation accuracy

The output parameter of the method is **centre**, the center of mass of the set of faces.

The method returns the area of the set of faces.

The method is declared in the *mip_solid_area_volume.h* file.

The *deviateAngle* parameter controls the calculation accuracy, and the computation time depends on its value. The *deviateAngle* parameter must be within the range 0.01 <= *deviateAngle* <= 0.35 radians.