Symmetry of objects

Introduction

The operation Symmetry of the objects allows for the duplication of the objects by symmetry with respect to:

The operation Symmetry of the objects is describe by:

A coordinate system for the creation of points (active coordinate system in the list available on the graphic View)
A list of objects on which the symmetry must be applied
The type of symmetry
The entity in relation with which the symmetry must be applied
The appearance of the resulting objects (color and visibility)


Dialog box	Illustration

The table below presents the available types of symmetry.


Symmetry in relation to …	Description	Illustration
Point	The point in respect to the symmetry which is defined can be : An existing point belonging to an object that is not part of the objects to be turned symmetric An existing point belonging to one of the objects to be turned symmetric An isolated reference point
Line	The line in respect to which the symmetry is defined can be: An existing line belonging to an object that is not part of the objects to be turned symmetric An existing line belonging to one of the objects to be turned symmetric An isolated reference line
Face	The face in respect to which the symmetry is defined can be: An existing face belonging to an object that is not part of the objects to be turned symmetric An existing face belonging to the objects to be turned symmetric
Reference plane	The plane in respect to which the symmetry is defined can be: One of the predefined reference planes One of the planes created by the user

The creation of an operation of Symmetry has as results :

A geometric operation SYMMETRY _1.
As many geometric operations as the objects to turn symmetric SYMMETRY_1_1, SYMMETRY_1_2… (it permits to isolate each object turned symmetric and to use them independently then).
As many objects as the objects to turn symmetric OBJ_SYMMETRY _1_1, OBJ_SYMMETRY _1_2, …
The addition of the geometric operation SYMMETRY _1 in the list of geometric operations of each of origin objects
The addition of the geometric operations SYMMETRY_1_1, SYMMETRY_1_2… in each of the objects resulting from the symmetry (OBJ_SYMMETRY _1_1, OBJ_SYMMETRY _1_2, …)

The different ways to access the operation Symmetry are:

The creation process of a symmetry of objects is presented in the table below.


Stage	Description
1	Choice of the coordinate system of creation
2	Opening the dialog box Symmetry
3	Choice of the name of the generated Geometric operation (by default: SYMMETRY_1)
4	Choice of objects on wich the symmetry must be applied
5	Choice of type of symmetry (in relation to a point, line, face, a reference plane)
6	Choice of the entity in relation to which the symmetry must be applied
7	Validation by clicking on OK

In the modification only the originating entity in relation to the applied symmetry is modifiable.

The list of objects generated by the symmetry is not modifiable

The type of symmetry is not modifiable

By means of an example, here are the geometric operations and the objects that are created during the operation of symmetry of objects.

Studied example: symmetry of a block and a cylinder in relation with a reference plane


	Before symmetry	After symmetry
Data Tree
Objects
Geometric operations	2 geometric operations: BLOCK_1: creation of the object OBJ_BLOCK_1 CYLINDER_1: creation of the object OBJ_CYLINDER_1	3 new geometric operations: (Father) SYMMETRY_1: creation of the symmetry (Son) SYMMETRY_1 _1: creation of the object OBJ_SYMMETRY_1_1 (Son) SYMMETRY_1_2: creation of the object OBJ_SYMMETRY_1_2
Building the origin tree of the object block
Building the origin tree of the object cylinder
Building trees of the resulting objects	_
Building trees of the resulting objects	_