.. role:: blue
   :class: blue

Constructing Model Flat Projection
==================================
.. _Constructing_Model_Flat_Projection_:

.. kernel version:

The method

.. code-block:: cpp

   void GetVestiges( const MbPlacement3D &        place,
                           double                 znear,
                     const RPArray< MbLump > &    lumps,
                     const MbProjectionsObjects & objects,
                           MbVEFVestiges &        result,
                           bool                   invisible,
                           VERSION                version );

constructs a flat projection of a set of solids and other objects.

The input parameters of the method are:

- **place** – projection plane,
- **znear** – observation point parameter,
- **lumps** – solids projected in local coordinate systems,
- **objects** – other projected objects,
- **invisible** – flag indicating construction of invisible lines,
- **version** – construction version, the latest version is Math::DefaultMathVersion().

The output parameter of the method is **result**, a structure that contains information about the projection.

The method does not return a value.

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

The projection plane is the XY plane of the **place** local coordinate system.

The *znear* parameter determines the type of image. When *znear* = 0, a parallel projection of objects is constructed. The **lumps** parameter contains solids and matrices that transform them from the local coordinate system. The **objects** parameter contains auxiliary objects required to format the projection: auxiliary points, curves, conventional notations, and annotation objects. The *invisible* parameter indicates whether invisible lines must be constructed. In some cases, when invisible lines are not constructed, the method runs noticeably faster.

Fig. 1 shows a solid whose projection lines onto a plane parallel to the screen plane are shown in Fig. 2. Fig. 3 shows only the visible projection lines of the solid presented in Fig. 1.

.. figure:: ../../pictures/R.2.2.1.png
   :width: 9cm
   :align: center

   Fig. 1

.. figure:: ../../pictures/R.2.2.2.png
   :width: 9cm
   :align: center

   Fig. 2

.. figure:: ../../pictures/R.2.2.3.png
   :width: 9cm
   :align: center

   Fig. 3

The last parameter of the method is used to support previous construction versions.

The

.. code-block:: cpp

   void VisualLinesMapping( const MbPlacement3D &     place,
                                  double              znear,
                            const RPArray< MbLump > & lumps,
                                  MbVEFVestiges &     result,
                                  bool                invisible = true );

method constructs a flat projection of a set of solids and differs from the GetVestiges\() method by the absence of additional **objects**.