Custom Elements are collections of Surfaces, Curves, and Collection Curves, and are used to define a custom geometry not available through one of the Element types (Lenses, Mirrors, Prisms). A Custom Element cannot contain other Custom Elements or Sub-Assemblies.
This command can be accessed in the following ways: •Menu > Create > New Custom Element •Ctrl + Alt + E •Toolbar button: •On the Geometry folder (or any of its child nodes) in the object tree view, right mouse click and select "Create New Custom Element" from the list menu
In FRED, Elements are pre-defined collections of Surfaces and Curves used to model objects such as lenses, prisms, and mirrors. The individual Surfaces and Curves used to define an Element can be viewed and their Surface types, Materials, Coatings, Scatter, Grating, Glue, and Visualization properties can be altered, but their Trimming Volumes cannot be changed from their individual dialogs. Trimming Volumes for these Surfaces and Curves can only be changed using the corresponding Edit/View Lens/Mirror/Prism dialog, accessible either by double clicking on the element node in the object tree view or by right mouse clicking on the element node in the object tree view and selecting Edit/View Lens/Mirror/Prism from the list menu.
Custom Elements are arbitrary user defined collections of Surfaces and Curves through which the user can define any custom geometry. In a Custom Element, each Surface must be edited separately.
The advantage of an Element is that Lens, Prism, or Mirror characteristics such as focal length, bending, etc. can be simply defined using the Edit/View Lens/Mirror/Prism dialogs and each of the Surfaces and Curves comprising that Element will be updated automatically. For example, the curvatures of the surfaces defining a Lens Element are automatically updated when the focal length of the Lens Element is specified in the Edit/View Lens dialog. In contrast, if the same lens were a custom element, each of the surface curvatures would have to be individually specified (and calculated for that matter) to achieve the appropriate focal length.
Converting to a custom element An Element can be converted to a custom element by right mouse clicking on the Element in the object tree view and selecting "Convert to Custom Element" from the list menu. This operation is irreversible and eliminates the possibility of modifying the Element parameters (focal length, bending, etc.) through a single dialog.
By default, Surfaces, Curves and Collection Curves created inside of a Custom Element are assigned the Custom Element's coordinate system as their starting coordinate system. This allows the individual Surfaces, Curves and Collection Curves inside of the Custom Element to be positioned relative to each other while the entire Custom Element can be easily moved as a unit in any other coordinate system.
|
||||||||||||||||||||||||||||||||||||||||||||||||
