Using Blend Shapes

If using Maya 2018 or above, please check the following Known Issue with blendshapes.

1. Define the blend shapes in the Character File (.gcha).

When the skeleton is loaded in the Character Maker, it automatically detects the blend shapes and list them under the Blend Shapes Panel of the Skeleton Tab. If you want to manually update the list, select the blend shape node in maya and click the + button next to the tab. Make sure that the same blenshape nodes have the same name when the Character is exported as a Geometry File.

2. Save the blend shape animations in a Motion File (.gmo)

Use the Character File created at step 1 to export your animation. The animated blend shapes will be automatically saved when the motion is saved from the Motion Tab. Make sure that the blenshape nodes in the animation have the same name than the one in the Character File.

3. Generate blend shape mapping file (.gmm)

This step is only required if you want to replay the blend shapes animations (.gmo) on a Character different than the one it was used as source (.gcha). The blend shape mapping found in the Motion Mapping Tab allows to map the blend shapes of the character currently loaded in the Character Maker to the ones in the selected Reference motion.

4. Verify the Motion File (.gmo) in the Motion Clip Preview

Launch the Motion Clip Preview Tool either from the Motion Clip tab in the Behavior Editor or in the attributes of the Motion Clip. The preview lists the parameters of the blend shapes. 

5. Make a Simulation

One all the files have been created, they can be used in a Simulation. The result of the blend shape animation can be seen when using the Render Previz Display Mode of the Entity Type.
However, note that for performance considerations, only up to 14 blend shapes will be visible in the viewport (see details here). Obviously, all blend shapes will be visible in the render.