Blend Shape

(Updated 08/17/2022)

This function adds differences to the model geometry. This is a convenient feature that allows modeling without worrying about the number of parameter multiplications.
Blend Shape can be added to the following three types of objects.

  1. ArtMesh
  2. ArtPath
  3. Warp Deformer


Creating Blend Shape Parameter

To create Blend Shape Parameter, click the [Create Parameter] button in the Parameter.

In the [Create New Parameter] dialog, check [Blend Shape] to create Blend Shape Parameter.
It is recommended that the range of Blend Shape Parameter be set to a minimum value of “0”, a default value of “0”, and a maximum value of “1”.

The created Blend Shape Parameter will be marked with a rectangular border at the value of “0.0”.


About Blend Shape's Key Forms

Adding Keys

Select the Blend Shape Parameter and the object to which you want to add the keyform, then execute [Add 2 Keyforms].

Then, a rectangle key is added to the minimum value “0.0” and the maximum value “1.0” of the Blend Shape Parameter, one by one.

Blend Shape Parameter are not subject to the following features.

• Key Form Editing
• Multiple Keys Editing
• Extended Interpolation
• Reflect Motion
• Arrange Parameter Configuration for Selected Object
• Delete deformer and pass on its parameters to child component (if the parent is the Blend Shape itself.) 



Key Deletion

Blend Shape keys can be deleted from the keyform in the same way as normal parameters.


When Editing Key Forms

The key form can be edited by selecting the Blend Shape key in the Parameter.
When a Blend Shape's keyform is editable, the message “Blend Shape is editable: <<parameter name>>” appears in the lower right corner of the view.

About the Key

There are two types of keys for Blend Shape Parameter.

(1) Base key:
This is the Blend Shape Parameter's own key and is used to determine the parameter's influence.
One is automatically added to every parameter for Blend Shape, and no object can have a key form.
When no other keys are available, the base key is automatically deleted.

(2) Key of Blend Shape:
The object has the key form of the Blend Shape in the key at (2).
Adding a key to a Blend Shape Parameter adds the key to the Blend Shape.

You can also [Choose], [Reflect], [Adjust], and [Change] keyforms for Blend Shape keys.
Basically, the behavior is the same as before, but please note the following specifications specific to Blend Shape Parameter.

  • [Reflect] swaps the positive and negative values of the key. The behavior differs from normal “inversion”.
  • The [Adjust] cannot change the value of the base key from “0.0” to another value, nor can it set the value of another key to the same value as the value of the base key.
  • • [Change] can only be applied to Blend Shape Parameter for which the currently selected object does not have a key.


If Multiple Blend Shape Keys Are Selected

If multiple Blend Shape keys are selected, one editable keyform is selected for each selected object.
Multiple key forms of a single object cannot be subject to editing at the same time.
Please see below for specific specifications.

 Number Description Detail
(1) With only one key selected in the Blend Shape

You can edit the keyforms of Blend Shape.


Two keys of the currently selected Blend Shape

When only one parameter is selected, it can be edited.

(3) Blend Shape key with multiple selections

When multiple Blend Shape keys are selected, the parameter to be edited cannot be specified. Select and edit one parameter.

Editing the keyforms of objects with Blend Shape is more complex in behavior than for objects without Blend Shape.
To prevent accidental editing, it is recommended that when editing the keyform of a Blend Shape, the value of the Blend Shape Parameter that is not being edited be set to the same value as the base key (0.0).


Blend Shape Transformation

Blend Shape deformation consists of two components: [Weight] and [Shape Difference].


 It is based on the distance between the current value of the parameter and the key, which is always 0% at the base key and can vary up to 100%.

Shape Difference

The difference between the Blend Shape keyform and the “keyform closest to the default form of the non-Blend Shape keyform”.

To prevent accidental editing of Blend Shape deformations, keep the following in mind.

  •  Default values for all parameters must be keyed. [Lock default Deformer] must be enabled.
  •  After editing a Blend Shape's keyform, do not change the default values of the object and its associated parameters.
  •  Do not edit the default form.

In light of these considerations, it is strongly recommended that Blend Shape-related modeling work be undertaken only after the need to change default forms or edit surrounding key forms has been completely eliminated.



Example of Blend Shape Creation

Here is an example of creating a Blend Shape, using the following square shape.

After adjusting the square in its normal keyform (angle X,Y), create a keyform for the Blend Shape.
In the keyform we created for the Blend Shape, the square is the base key (0.0) and the Blend Shape key (1.0) is transformed to an octagon.
If you move the normal keyform with the Blend Shape key set to (1.0), you will see that an octagon has been added to all (angle X,Y) keys.


To Set Multiple Blend Shape

In addition to the “octagonal shape” created, the following “triangular shape” is created and explained below.

“Octagonal shape” “Triangular shape”


After creating a “triangular shape” for the Blend Shape key, the shape was added in the normal keyform.


However, when I check the shape of the object in the view when both Blend Shape keyforms are set to (1.0), it is a different shape, neither octagonal nor triangular, and it is misshapen.

Unintended shape suppression can be adjusted using the [Blend Shape Weight Limit Settings] function.
For a detailed explanation of the setting method, please refer to “Limit Settings for Blend Shape Weights”.



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