Parent Coordinate System

Navigation: FRED Basics > Parent Coordinate System

Page Contents

Description

Navigation

Controls

Application Notes

•Coordinate system and position

•Feature application

•Express each in the coordinate system of

Related Topics

Description

The Parent Coordinate System feature allows the user to change the coordinate system parentage of the descendants of a selected node. In the context of the dialog, descendants refer to the hierarchal order of the tree.

This utility cannot be used on highlighted Surfaces, Curves, or individual Sources since they cannot have any child nodes.

There are currently two options available:

Change each to the parent coordinate system of:

This option expresses the position and orientation of the descendants of the selected node in the coordinate system of an entity (selected via the entity picker). In this case, the parent coordinate system can be any of the following: Global Coordinate System, Self, the Optical Sources folder, an optical source node, the Geometry folder, a Geometry entity node, the Analysis Surfaces folder, or any analysis surface. It is not necessary for the parent coordinate system selection to follow the hierarchy of the tree, but circular references should be avoided.

Change each to the coordinate system of its immediate parent:

This option expresses the position and orientation of the descendants of the selected node in the coordinate system of their immediate parent(s). This is the default condition for any new geometry and follows the hierarchy rules of the tree.

Navigation

This feature can be accessed by right mouse clicking on a node in the Optical Sources or Geometry folder and selecting "Parent Coordinate System" from the list menu.

Controls

Control	Inputs / Description	Defaults
Highlighted Entity	No input required.	Displays the name of the selected entity.
Operation to Perform on the Descendants of the Highlighted Entry
Change each to the coordinate system of	Select an entity to use as the coordinate system using the entity picker.	Selected entity.
Change each to the coordinate system of its immediate parent	Restores the logical parent/child coordinate system relationships.	Not selected

OK	Accept settings and close dialog box.
Cancel	Discard settings and close dialog box.
Apply	Apply settings and keep dialog box open.
Help	Access this Help page.

Application Notes

Coordinate system and position

Changing the Parent Coordinate System of an entity does not change its location. FRED automatically computes and applies the correct coordinate system transformations relative to the new parent coordinate system to maintain its position.

Feature application

A common application for this utility would be to convert the coordinate system of an entity copied from another location into that of the highlighted node. During a copy operation, FRED maintains all of the coordinate system references internal to the entity (i.e., a subassembly with a number of custom elements and surfaces) but places the logical parent node into the coordinate system of its logical parent. For example, subassembly copied into the Geometry folder would have the Geometry folder as its parent coordinate system. Similarly, a custom element copied into a subassembly would have the subassembly as its parent coordinate system. Note that the copy operation does not move an element and that its location is re-expressed in the coordinate system of the new parent.

Express each in the coordinate system of

When the dialog is opened, the default option is to express the descendants of the highlighted entity in the coordinate system of the highlighted entity. The coordinate system can be changed to any valid model node by using the entity picker and selecting the new parent. This operation can sever the logical coordinate system relationships between parent and descendant nodes because the parent is unaffected, which can have unintended consequences. Use with caution.