.. role:: blue
   :class: blue

Constructing a Thin-Wall Body
==============================
.. _Constructing_a_Thin-Wall_Body_:

.. kernel version: 118041

The function

.. code-block:: cpp

   MbResultType ThinSolid(       MbSolid &          solid,
                                 MbeCopyMode        sameShell,
                                 RPArray<MbFace> &  outFaces,
                                 SweptValues &      params,
                           const MbSNameMaker &     names,
                                 bool               copyFaceAttrs,
                                 MbSolid *&         result );

constructs a thin-wall body by excluding the specified faces from the source body and optionally assigning a uniform thickness to the remaining faces.

The input parameters of the function are:

- **solid** is the source body;
- **sameShell** is the copying mode of the source body;
- **outFaces** are the faces to be removed from the body;
- **params** are the operation parameters;
- **names** is the name maker;
- **copyFaceAttrs** is the flag for copying attributes from source faces to offset faces.

The output parameter of the function is the **result** object that contains the constructed body.

The function returns an operation result code from the :ref:`MbResultType <MbResultType_>` enumeration.

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

The function removes the specified faces **outFaces** from the source body **solid** and "assigns the specified thickness" to the remaining faces.

The parameter **sameShell** controls the transfer of faces, edges, and vertices from the source body **solid** to the constructed body **result** and can take one of four values:

- *cm_Same = 0* (shell is not copied);
- *cm_KeepHistory* (source shell and its copy share base surfaces, vertices, and faces unchanged by the operation);
- *cm_KeepSurface* (source shell and its copy share base surfaces);
- *cm_Copy* (source shell and its copy have no shared data).

The :blue:`MbeCopyMode` enumeration is described in detail in the section :ref:`Copying a Set of MbFaceShell Faces <Copying_a_Set_of_Faces_>`.

The parameter **params** contains information about the wall thickness of preserved faces and the closure of the constructed body **result** (see *op_swept_parameter.h*).

The wall thickness of preserved faces can be equal to **params**.\ *thickness1* in the positive normal direction of the face or **params**.\ *thickness2* in the negative normal direction.

If **params**.\ *shellClosed* = *false*, a non-closed body will be constructed.

The parameter **params**.\ *checkSelfInt* specifies whether the construction result should be checked for self-intersection. By default, **params**.\ *checkSelfInt* = *false* (no check is performed).

The **params**.\ *mergeFlags* field controls merging of geometrically similar faces and edges (*mergeFaces* = *true* — merge similar faces, *mergeEdges* = *true* — merge similar edges).

The parameter **names** provides naming for faces, edges, and vertices of the constructed body.

For the operation to succeed, the faces to be removed **outFaces** must not have smooth mating edges along their common boundary with the preserved faces of the source body.

The parameter **copyFaceAttrs** controls copying attributes from source faces to offset faces.

Figure 1 shows the source body **solid** and faces to be removed **outFaces**:

.. figure:: /MODELER/OPERATIONS_ON_BODIES/pictures/M.2.13.1.png
   :width: 12cm
   :align: center

   Fig. 1

Figure 2 shows the constructed thin-wall body **result** with preserved faces thickened inward from the source body:

.. figure:: /MODELER/OPERATIONS_ON_BODIES/pictures/M.2.13.2.png
   :width: 12cm
   :align: center

   Fig. 2

Figure 3 shows the constructed thin-wall body **result** with preserved faces thickened outward from the source body:

.. figure:: /MODELER/OPERATIONS_ON_BODIES/pictures/M.2.13.3.png
   :width: 12cm
   :align: center

   Fig. 3

Figure 4 shows the constructed non-closed body **result**:

.. figure:: /MODELER/OPERATIONS_ON_BODIES/pictures/M.2.13.4.png
   :width: 12cm
   :align: center

   Fig. 4

Figure 5 shows the thin-wall body constructed with an empty set of faces to be removed:

.. figure:: /MODELER/OPERATIONS_ON_BODIES/pictures/M.2.13.5.png
   :width: 12cm
   :align: center

   Fig. 5

The :blue:`ThinSolid`\() function adds the :blue:`MbShellSolid` builder to the log of the constructed body, which contains all necessary data for performing the operation. The :blue:`MbShellSolid` builder is declared in the *cr_thin_shell_solid.h* file.

In the test application *test.exe*, thin-wall body construction is performed using the menu command "Create → Solid → By faces processing → Thin-walled with a constant thickness".