When cloning in Max, you're offered the option to create the clone as a copy, an instance, or a reference. This is true not only for objects, but for materials, modifiers, and controllers as well.
When an object is cloned, the Clone Options dialog box appears. This dialog box enables you to select to make a copy, an instance, or a reference of the original object. Each of these clone types is unique and offers different capabilities.
A copy is just what it sounds like-an exact replica of the original object. The new copy maintains no ties to the original object and is a unique object in its own right. Any changes to the copy do not affect the original object, and vice versa.
Instances are different from copies in that they maintain strong ties to the original object. All instances of an object are interconnected, so that any geometry modifications (done with modifiers or object parameters) to any single instance changes all instances. For example, if you create several instances of a mailbox and then use a modifier on one of them, all instances are also modified.
Note | Instances and references can have different object colors, materials, transformations (moving, rotating, or scaling), and object properties. |
References are objects that inherit modifier changes from their parent objects, but do not affect the parent when modified. Referenced objects get all the modifiers applied to the parent and can have their own modifiers as well. For example, suppose that you have an apple object and a whole bunch of references to that apple. Applying a modifier to the base apple changes all the remaining apples, but you can also apply a modifier to any of the references without affecting the rest of the bunch.
At any time, you can break the tie between objects with the Make Unique button in the Modifier Stack. The Views Show Dependencies command shows in magenta any objects that are instanced or referenced when the Modify panel is opened. This means that you can easily see which objects are instanced or referenced from the current selection.
Learning how the different clone options work will save you lots of future modifications. To investigate these options, let's take a quick trip to the local doughnut shop.
To clone some doughnuts, follow these steps:
Create a doughnut using the Torus primitive by selecting Create Standard Primitives Torus, and then dragging and clicking twice in the Top viewport to create a torus object.
Click the torus object in the Top viewport to select it.
With the doughnut model selected, click the Select and Move button (or press the W key). Hold down the Shift key, and in the Top viewport, move the doughnut upward. In the Clone Options dialog box, select the Instance option, set the Number of Copies to 5, and click OK. Click the Zoom Extents All (or press the Shift+Ctrl+Z key) button to widen your view.
Select all objects with the Edit Select All (Ctrl+A) command, and then Shift+drag the doughnuts in the Top viewport to the right. In the Clone Options dialog box, select the Instance option again and 3 for the Number of Copies and click OK. This creates a nice array of two dozen doughnuts. Click the Zoom Extents All button (or press the Z key) to see all the doughnuts.
Select a single doughnut, and in the Parameters rollout of the Modify panel, set Radius1 to 20 and Radius2 to 10.
This makes a nice doughnut and changes all doughnuts at once.
Select the Modifiers Parametric Deformers Twist command. Then in the Parameters rollout of the Command Panel, enter 25 in the Angle field and select the Y Twist Axis.
This adds a slight bend to the doughnuts.
CROSS-REF | You can use modifiers to alter geometry. You can learn about using modifiers in Chapter 12, "Introducing Modifiers and Using the Modifier Stack." |
Figure 9.3 shows the doughnuts all changed exactly the same. You can imagine the amount of time it would take to change each doughnut individually. Using instances made these changes easy.
Figure 9.3: Two dozen doughnut instances ready for glaze
Now that we have filled our bellies with doughnuts, we need some healthful food for balance. What better way to add balance than to have an apple or two to keep the doctor away?
To create some apples using referenced clones, follow these steps:
Open the Referenced Apples.max file from the Chap 09 directory on the DVD.
Select the apple, and Shift+drag with the Select and Move (W) tool in the Top viewport to create a cloned reference. Select the Reference option in the Clone Options dialog box.
Select the original apple again, and repeat Step 2 until several referenced apples surround the original apple.
Select the original apple in the middle again, and choose the Modifiers Subdivision Surfaces MeshSmooth command. In the Subdivision Amount rollout, set the number of Iterations to 2.
This smoothes all the apples.
Select one of the surrounding apples, and apply the Modifiers Parametric Deformers Taper command. Set the Amount value to 1.0 about the Z-axis.
Select another of the surrounding apples, and apply the Modifiers Parametric Deformers Squeeze command. Set the Axial Bulge Amount value to 0.3.
Select another of the surrounding apples, and apply the Modifiers Parametric Deformers Squeeze command. Set the Radial Squeeze Amount value to 0.2.
Note | As you apply modifiers to a referenced object, notice the thick gray bar in the Modifier Stack. This bar, called the Derived Object Line, separates which modifiers get applied to all referenced objects (below the line) and which modifiers get applied to only the selected object (above the line). If you drag a modifier from above the gray bar to below the gray bar, then that modifier is applied to all references. |
Using referenced objects, you can apply the major changes to similar objects, but still make minor changes to objects to make them a little different. Figure 9.4 shows the apples. Notice that they are not all exactly the same.
Figure 9.4: Even apples from the same tree should be slightly different.