Create blend shapes using multiple target objects

With this method of shape animation, you create multiple target objects that are duplicates of the base object, then modify the vertex positions on each one of the target objects into the forms you want. For example, you can use this method for facial animation, with each target object representing a different facial expression.

This method of shape animation creates more geometry in the scene, but it's easy to return to the target object for modifying. Having target objects also lets you take their geometry into sculpting programs, such as Autodesk Mudbox, to do further editing and then import them back into Maya LT. As well, you can use deformers such as lattices to deform a target object. See below for tips on dealing with target object geometry.

You can also blend a hierarchy or group of target objects on a hierarchy or group of base objects. Make sure that both hierarchies have the same number of children and parenting relationships. Each child in the target object hierarchy blends with its corresponding child in the base hierarchy. The order of children in the Outliner (or Hypergraph) determines which children blend, so you can change the order of the children by middle-dragging them in the Outliner so that the hierarchies match.

To create blend shapes using multiple target objects

1. Create the base object in a neutral pose. This is the object to be deformed with the target shapes.

   For more predictable deformation results, it's best to not change the number of vertices, faces, or edges on the base object after you have created the blend shape deformer. They should match those of the target objects. However, if you do, you can propagate those changes to the target objects - see Propagate topological changes from base object to target objects. This deletes the Input history on an object.

2. Duplicate this object as many times as the number of the target shapes you want to set to create target objects. Move them out of the way of the camera.

   When you create the target objects, don't freeze their transformation after you have moved them. They need to have the same transform values as the base object. It's better to create the target objects where the base object is (the scene origin is best), freeze their transforms (choose Modify > Freeze Transformations from the main menu), and then move them to where you want them.

3. Deform the components (vertices, faces, edges) on the target objects using any method of deformation (Sculpt tools, Transform tools, or other deformers).
4. When you're finished with editing the target objects, press Shift and select each of the deformed objects in the order that you want the target shapes to be animated, then add the base object to the selection last. You can change the order of the resulting target shapes later in the Shape Editor - see Swap target objects.

   If you're blending hierarchies or groups, select the parent (its transform node) of the target object hierarchy or group first, then add the parent of the base object hierarchy or group to the selection last.

5. Create a blend shape deformer as described in Create blend shape deformers.

   If you want to delete the target objects automatically when you create the blend shape deformer, see Delete target objects.

6. In the Shape Editor, you can see that a Blend Shape Deformer (blendShape node) is created, and a target shape is created for each target object you selected.
7. In the Time Slider, go to the first frame where you want to set a key (such as for a neutral expression or pose).
8. Select a target shape and drag its Weight slider (or enter a value in the text box) to set its influence on the blend shape for the base object - see Set weights for target shapes.
   Note: You can also set the Weight values for each target shape in the Channel Box or the Attribute Editor.
9. In the Shape Editor, click the Key icon () at the right end of each target shape's weight slider to set a key at this frame for the current value, or right-click the icon and choose one of the options (Key Current, Key at 0, or Key at 1).
   Note: You can also key the weight values for each target shape in the Channel Box - see Key the blend shape weights.
10. Repeat the last three steps to animate the shape deformation over time.

Tips for using multiple target objects

Having geometry for target objects can make your scene larger, but here are some ways of optimizing that:

• Delete the target objects automatically when you create the blend shape deformer - see Delete target objects. If you later decide that you want the target objects back, you can easily rebuild them from their target shapes - see Create a new object from the target shape.
• Delete the target objects after you're done creating the blend shape animation.
• Add the target objects to a display layer and then hide or template this layer (see Organize objects in display layers).
• Save the selected target objects in another scene (File > Export Selection) and import this file (File > Import) when you need the objects in your scene again.