X3D comes with a fixed set of objects, called nodes, which will cover most of your needs. But its creators have also planned ahead, knowing that you'll sometimes have to create own objects, and you'll often want to assemble the same types of nodes in similar ways, with only small changes. The prototyping feature added to X3D lets you create objects that you can reuse, changing certain characteristics of the objects when desired.
With Titania you can display, edit and use extern prototypes and protoypes within the Outline Editor:
To display extern prototypes and prototypes, open the context menu of the Outline Editor and choose View > Extern Prototypes and View > Prototypes.
This application feature is not complete. It will be fully implemented in future versions of Titania.
At the moment you can use your prefered text editor to create an extern prototype or prototype interfaces. Save it as single file and drag and drop this file into the browser window. Note: disable File > Import As Inline within the global menu.
Extern prototypes are references to prototypes located somewhere on your hard disk or in the Internet. Extern prototypes define a interface that can be a subset of the prototype's interface. You can switch to the extern prototype's scene by choosing Set As Current Scene from the context menu. As soon as the file is loaded the prototype is displayed within the Outline Editor:
You can fully expand the prototype and all of it's nodes. The double circle before the node type name indicate that the node it within another execution context. To edit such nodes you must go into the prototype by setting the prototype as current scene. The the icon before the node type name changes to a single circle, indicating that you are within a prototype and the nodes are fully editable now:
Your prototype may define one or more interface fields of various types. These fields can be connected to fields of a node within the prototype body. There are special rules when prototype interface fields can connected to node fields. The most important rule is, that the access type of both fields have to be of the same type. Titania handles this automatically and only shows you the fields that can be connected to node fields when creating references.
Create a Reference
To create a reference to an interface field, open the context menu over a node field and choose Create Reference To > YourInterfaceFieldName. Note: the menu item is only visible if it is possible to create a reference. Once you have created the reference, the field name is displayed in bold face.
Remove a Reference
To remove a reference to an interface field, open the context menu over a node field in bold face and choose Remove Reference To > YourInterfaceFieldName. This will disconnect the releationship between the interface field and your node field.
Once you have created a prototype, you want to use them within your scene one or more times. To use a prototype, it is important that this prototype is within your scene or you can save the prototype as external file and only create a reference to that file by importing the prototype. Now you can open the context menu over an extern prototype or prototype and choose Create Instance. The so created instance is placed as root node at the end of your scene graph. You can now follow the steps from creating group hierarchies to incorporate your instance into your scene.
You cannot easily remove prototypes as long as there is an instance of an extern prototype or prototype within your scene, but if not, you are free to remove it. Just choose File > Remove Unused Prototypes and the prototypes are immediately removed from within your scene.
An extern prototype will often be the way of your choice when you use a prototype within a scene, but then you are responsible to manage the references to that file. This means, when you move your prototype to another folder then you have to change the url field of your extern prototype.
Also at some time you will have a library of your own prototypes, but how to use them within your projects? When you have imported the prototype as extern prototype and then made a change at the interface of your prototype, then you could come in trouble. Often the file can not be loaded due to parser errors, as the interface is not the same. So it is often more feasible to copy the used prototypes to your project folder and to create a extern prototype reference from there to it.