Edit Deformers > Blend Shape > Add >

Specify Node

If the base object shape you selected is influenced by only one blend shape deformer, you don’t need to turn Specify Node on. If on, you can specify BlendShape Node and Existing Nodes. Specify node is off by default.

BlendShape Node

Specifies the name of the blend shape deformer to which you want to add the target object shapes. BlendShape Node is available only when Specify Node is on.

Existing Nodes

Lists all the blend shape deformer nodes in the scene, and indicates the blend shape deformer to which you want to add target object shapes. Existing Nodes is available only when Specify Node is on.

Add In-Between Target

Specifies whether you want to specify the Target Index and In-Between weight. Typically, you want to specify the Target Index and InBetween weight to control the effect of the target object shapes you are adding.

Target Index

If the blend shape deformer blends target object shapes in parallel (the In-Between creation option was off when you created the blend shape deformer), you can add the new target object shapes so that they work in series with one of the existing target object shapes. One quick way you can identify the appropriate value for Target Index is by looking at the order of the target sliders in the Blend Shape Editor (Window > Animation Editors > Blend Shape). Note that in the editor, each target object shape has its own target slider. In the editor, going from left to right, the Target Index value for the left-most target slider would be 1, the next 2, and so on.

If the blend shape deformer blends target object shapes in series (the In-Between creation option was on when you created the blend shape deformer), Target Index can only be 1 because there is only one target slider. In this case, you don’t have to specify Target Index, but you do need to specify the In-Between Weight.

In-Between Weight

Specifies the weight at which the added target object shape will have maximum influence. Use slider to select values from 0 to any value less than 1. Do not select 1 because 1 is the weight at which the existing target object shape has its maximum influence.

Target Shape Options

Specifies whether to check if the added target object shapes have the same topology as the base object shape and the existing target object shape(s). For example, if using NURBS objects, you could check if all the shapes have the same number of CVs. Click Check Topology to turn it on or off. Check Topology is on by default.