.. role:: blue
   :class: blue

Construction of an extrusion surface
====================================
.. _Construction_of_Extrusion_Surface_:

.. kernel version: 118057

The function

.. code-block:: cpp

   MbResultType ExtrusionSurface( const MbCurve3D  &  curve,
                                  const MbVector3D &  direction,
                                        bool          simplify,
                                        MbSurface  *& result )

constructs an extrusion surface.

The input parameters of the function are:

- **curve** — a generatrix curve;
- **direction** — an extrusion vector that defines a direction and a length;
- **simplify** — a flag for simplifying a surface, if it is possible (for example, reducing it to a simpler analytical type when it is allowed).

The output parameter of the function is the constructed surface **result**.

If successful, the function returns :blue:`rt_Success`; otherwise, it returns a result code from the :blue:`MbResultType` enumeration (see *mb_operation_result.h*).

The function is declared in the *action_surface.h* file.

An extrusion surface is one of the motion surfaces obtained by moving a generatrix curve along a given trajectory (a directing curve). For an extrusion surface, the trajectory is a straight-line segment defined by the **direction** vector. The extrusion surface is described in :ref:`MbExtrusionSurface extrusion surface <MbExtrusionSurface_Extrusion_Surface_>`. Figure shows a surface constructed by extrusion of a curve along a given vector:

.. figure:: /MODELER/SURFACE_CONSTRUCTION_METHODS/pictures/M.5.3.1.png
   :width: 12cm
   :align: center

In the test application *test.exe*, construction of an extrusion surface is performed by the menu command "Create → Surface → Based on curves → Extrusion".