File menu > XRef Objects
Externally referenced objects, XRef objects, appear in your current scene, but are actually referenced from external scene files. As a result, the source objects are protected from modifications you make to the XRef objects. Updates or changes made to the source objects are also updated in the target file where the XRef appears.
An XRef object appears like any other object in your gmax scene. However, in the modifier stack, none of the stack entries is available for change; the only entry is ôXRef Objectö. You can add additional modifiers to the object, but you cannot access the original ones unless you merge the XRef object into the scene.
XRef objects can be modified or transformed in your current scene just like any other object. XRef objects also allow the use of proxy objects to stand in or substitute for geometry. Use XRef objects to manage the complexity of your scene during animation by substituting ôlightweightö proxy objects for more complex geometry.
You can create a proxy by simplifying a clone of your existing model or you can build simple substitute objects like boxes or cylinders, or you can save a copy of the model in the early stages of modeling before you add the detail. You can even use an object from another scene.
Choosing XRef Objects from the File menu displays the XRef Objects Dialog where you add XRefs to your scene, as well as control their visibility, merge states, and set other options.
If your XRef object relies on another object in the source scene, the relationship will be preserved in the destination file (for example, objects with path constraints).
Procedures
To add an XRef object:
Choose File > XRef Objects.
Click the Add button in the XRef Objects dialog. An Open File dialog appears with a thumbnail browser to help you identify the file you want. Highlight the file you want to highlighting it in the list, then choose Open. The XRef Merge dialog appears.
Select the objects that youÆd like to appear in your current scene as XRef objects. You can choose as many as you want by holding down the CTRL key and choosing them from the list. You can filter the list using the List types radio buttons if your scene has a lot of objects you donÆt need to include. You can also sort the list alphabetically or by color or type.
If your objects have transform animation, you can ignore this at this time. If you want to ignore any other parametric animation you can turn it off in the XRef Objects dialog.
The objects appear in the lower window of the XRef Objects dialog. Make additional choices at this time if you like. You can control all the objects will update (either automatically or on demand). You can update the objectÆs material. You can enable or disable the objects, but disabled objects will not appear in the viewport and are not held in memory. Updating is done at the file level. All objects from any file are updated together.
To set a proxy object for an XRef object:
You can also choose to use a proxy object, substituting alternate geometry for the XRef object.
Add the object as an XRef.
After you add the object, highlight it in the XRef Objects window in the lower left.
The Add button changes to Set, and Add as Proxy becomes Set Proxy.
Turn on Set Proxy and choose the file and proxy object. This object will replace the XRef object in the scene.
The name of the proxy object appears in the lower list, followed by (Proxy for ôobjectnameö).
You can also define the proxy for an object in the Modifier panel. In the XRef Viewport Proxy group of the XRef Object rollout, turn on Use Proxy. Use the File Name and Object Name fields to browse and specify the file and object.
To add a proxy object before adding the XRef object:
You can begin with a proxy object and eliminate the need to load your detailed model and store it in memory.
Choose File > XRef Objects.
Click the Add As Proxy option and click the Add button.
Choose the file containing your proxy object.
Pick the object in the XRef Objects window in the lower-left.
The Add button changes to Set, and Add as Proxy becomes Set Proxy.
Turn off Set Proxy and click Set.
Choose the file and XRef object.
To update an XRef object material:
Pick the object from the lower left list in the XRef Objects dialog.
Either turn on Update Material in the XRef Objects group of the XRef Objects dialog, or turn on Update Material in the Options group of the XRef Objects rollout on the Modify panel.
Click Update Now in the XRef Objects dialog.
To convert an object in the scene to an XRef object:
Choose Convert Selected in the XRef Objects dialog after selecting the objects.
Choose a file name in which to save the source object.
The Convert Selected button actually saves the selected objects to a new file and then creates XRef objects from that file.
To change an XRef object into a scene object:
Select the XRef object, and then click Merge. The XRef object becomes a full-fledged object in the scene, giving you access to its modifier stack.