albertdelfosse opened this issue on Aug 21, 2008 · 12 posts
albertdelfosse posted Thu, 21 August 2008 at 10:21 PM
Found out how to do it! It involves using maya 8.5 or higher.
From maya 8.5 docs:
Deformers
What are blend shapes? Blend shape deformers let you change the shape of one object into the shapes of other objects.
Blend shape deformers let you to deform a surface into the shapes of other surfaces. You can blend shapes with the same or a number of vertices (or CVs). In character setup, a typical use of a blend shape deformer is to set up poses for facial animation.
Unlike other deformers, the blend shape deformer has an editor that lets you control all the blend shape deformers in your scene. You can use the editor to control the influence of the targets of each blend shape deformer, create new blend shape deformers, set keys, and so on.
Other software packages use the terms “morph,” “morphing,” and “shape interp” to refer to what Maya provides with blend shape deformers.
When creating a blend shape deformer, you identify one or more objects whose shapes you want to use to deform the shape of some other object. Objects whose shapes you want to use to deform the shape of another object are called target objects, and the object being deformed is called the base object.
Deformers
Blending objects with different topologies You can blend shapes with the same or different number of vertices or CVs.
When you create a blend shape deformer, you should turn the Check Topology creation option off if you want to blend objects that have different numbers of CVs or vertices. For more information on Check Topology, see Create Deformers > Blend Shape.
If objects have the same number of CVs or vertices but their order is different, Maya blends the shapes whether Check Topology is on or off. However, the position of the base CVs will be transformed to the position of the target CVs. This change might cause the object to blend in a way you might not expect. To ensure a smooth transition between base and target, make sure the order of CVs is the same in both objects.
In addition to blending individual objects, you can blend hierarchies of objects. Make sure both hierarchies have the same number of children and parenting relationships.
To blend hierarchies, you must select the parent of the target hierarchy (or hierarchies) first and the parent of the base hierarchy last before creating the blend shape. The parent of each must be a transform.
Each child in the base blends into its corresponding child in the target. The order of children in the Outliner (and Hypergraph) determines which children blend. If necessary, use the Outliner to change the order of objects in the hierarchies.
A common blend shape technique is to create duplicates of a base, deform the duplicates, then use them as targets. For example, you might make several copies of a face, and then alter the copies to create a smiling face, frowning face, a crying face, and so on. If you use this technique, turn on the Check Topology creation option when you create the blend shape deformer. This checks that the base and target hierarchy shapes have the same number of CVs. If the CVs are different and Check Topology is off, you might see, for instance, an eye blending into the nose. If Check Topology is on, the members of the hierarchies must have corresponding numbers of CVs.
Deformers
Create Deformers > Blend Shape Create Deformers > Blend Shape > ### Basic tab
Specifies the name of the blend shape deformer (the blend shape deformer algorithm node). You should rename this node so that its name reminds you of the role of the blend shape deformation (for example, lipSync). If you don’t specify a name, Maya provides the default name blendShapen.
Specifies the deformation scale factor. Use the slider to specify values from 0.0000 to 1.0000. Default is 1.0000.
Specifies whether the blend shape will be relative to the base object shape’s position, rotation, and scale. Click Local or World. The default is Local.
Local will blend the base object shape to the target object shape(s) while ignoring differences in position, rotation, and scale between the base object and the target object(s). For facial animation setup, you would typically want to select Local. In general, Local is useful when you want to have your target object(s) in various separate positions for easy viewing but don’t want their positions to affect the deformation.
World will blend the base object shape to the target object shape(s), taking into account any differences in position, rotation, and scale between the target object shape(s).
Specifies whether the blending will be in series or in parallel.
If on, the blending will be in series. Shape transitions will occur in the order in which you selected the target shape(s). The effect will be that the blend shape will be able to change from the first target object shape, to the second, and so on, back and forth through the series of target object shapes chained together as “in-between” shapes.
If off, the blending will occur in parallel. Each target object shape can influence the blending simultaneously in a parallel fashion rather than one after another in a series. Typically, for facial animation setup, you would want In-Between off so that you can have a variety of basic facial expressions that form the basis of all the possible expressions. Because the blending is in parallel, you can control the influence of each basic expression at any moment to get a nearly infinite variety of highly nuanced expressions. Default is off.
Specifies whether to check if the base shape and the target shape(s) have the same topology. For example, if using NURBS objects, you could check if all the shapes have the same number of CVs. Click on or off. Default is on.
Specifies whether to delete the target shape(s) after creation. Deleting target shapes can be useful if you don’t need to see or manipulate the target shape(s) and you want to improve display performance. However, be sure to save a copy of the target shapes in case you later decide you need to adjust them. Default is off.
Specifies the placement of the deformer node in the deformable object’s history.
Typically places the deformer immediately before the current final shape node.
Places the deformer immediately before the current final shape node. Default and Before typically provide the same placement.
Places the deformer immediately after the current final shape node, and creates a new final shape node.
Splits the input deformation history into two separate deformation chains, providing two final shapes originating from the same deformable object.
Creates a final shape that blends the object’s current input history in parallel with the new deformer.