Animation Blend Shapes

Preparing the Artwork

Once you have your Blend Shapes set up in Autodesk® Maya®:

• Export your selection to fbx ensuring the animation box is checked and blend Shapes under deformed models is checked.

• Import your FBX file into Unity (from the main Unity menu: AssetsAny media or data that can be used in your game or Project. An Asset may come from a file created outside of Unity, such as a 3D model, an audio file or an image. You can also create some asset types in Unity, such as an Animator Controller, an Audio Mixer or a Render Texture. More info
  See in Glossary > Import New Asset and then choose your file).

• Drag the Asset into the hierarchy window. If you select your object in the hierarchy and look in the inspectorA Unity window that displays information about the currently selected GameObject, Asset or Project Settings, alowing you to inspect and edit the values. More info
  See in Glossary, you will see your Blend Shapes are listed under the SkinnedMeshRenderer component. Here you can adjust the influence of the blend shape to the default shape, 0 means the blend shape has no influence and 100 means the blend shape has full influence.

Create Animations In Unity

It is also possible to use the Animation window in Unity to create a blend animation, here are the steps:

• Open the Animation window under Window > AnimationA collection of images that create a moving image when played sequentially. In Unity, an animation is the result of adding two different animation keys, at two different times, for the same animatable property. More info
  See in Glossary > Animation.

• On the left of the window click ‘Add Curve’ and add a Blend Shape which will be under Skinned MeshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
  See in Glossary Renderer.

From here you can manipulate the keyframesA frame that marks the start or end point of a transition in an animation. Frames in between the keyframes are called inbetweens.
See in Glossary and Blend Weights to create the required animation.

Once you are finished editing your animation you can click play in the editor window or the animation window to preview your animation.

Scripting Access

It’s also possible to set the blend weights through code using functions like GetBlendShapeWeight and SetBlendShapeWeight.

You can also check how many blend shapes a Mesh has on it by accessing the blendShapeCount variable along with other useful functions.

Here is an example of code which blends a default shape into two other Blend Shapes over time when attached to a gameobjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
See in Glossary that has 3 or more blend shapes:

//Using C#
 
using UnityEngine;
using System.Collections;
 
public class BlendShapeExample : MonoBehaviour
{
 
       int blendShapeCount;
       SkinnedMeshRenderer skinnedMeshRenderer;
       Mesh skinnedMesh;
       float blendOne = 0f;
       float blendTwo = 0f;
       float blendSpeed = 1f;
       bool blendOneFinished = false;
 
       void Awake ()
       {
          skinnedMeshRenderer = GetComponent<SkinnedMeshRenderer> ();
          skinnedMesh = GetComponent<SkinnedMeshRenderer> ().sharedMesh;
       }
 
       void Start ()
       {
          blendShapeCount = skinnedMesh.blendShapeCount; 
       }
 
       void Update ()
       {
          if (blendShapeCount > 2) {
 
                 if (blendOne < 100f) {
                    skinnedMeshRenderer.SetBlendShapeWeight (0, blendOne);
                    blendOne += blendSpeed;
                 } else {
                    blendOneFinished = true;
                 }
 
                 if (blendOneFinished == true && blendTwo < 100f) {
                    skinnedMeshRenderer.SetBlendShapeWeight (1, blendTwo);
                    blendTwo += blendSpeed;
                 }
 
          }
       }
}