Lesson 6: Setting up Jiggle deformation

So far you have a working leg with flexing muscles. To provide even more control, Maya Muscle lets you paint Jiggle weights per-point on your mesh.

Note

You can use the Jiggle deformer even if you are not doing muscle skinning. For example, you can paint and add weights for jiggling on any moving object to get jiggle effects, even if the object is skinned with a Maya skinCluster, or not skinned at all.

Open the scene for the lesson

Load the file you worked on in the previous lesson or load the DragonLeg_Jiggle_Start.mb file.
This rig has a complete leg with bones and muscles, and with Sticky and Sliding weights applied.

Enable Jiggle deformation

Like other features, the Jiggle deformer can be turned on and off independently. When Jiggle occurs, Jiggle collisions can also be enabled to help make sure points do not move into bones and muscles that are sliding. Note that there is no self-collision, this is simply sliding collision if the Sliding deformer is also enabled.

Select the skin mesh.
In the Attribute Editor, select the cMuscleSystem1 tab.
Turn on Enable Jiggle.

Paint Jiggle weights

Select the skin mesh.
Select Muscle > Paint Muscle Weights.
The Muscle Paint window opens.
In the Muscle Paint window, select Jiggle from the Weights drop-down menu.
Paint Jiggle weights in the middle center of the leg, as shown. (You can paint weights on other areas of the skin mesh where you want to have per-point skin jiggle.)
Experiment with painting different areas of the mesh, and playblast your animation to see the results (Window > Playblast).
Typically, jiggle-related weights benefit from a smoother falloff on the painting. Close the Muscle Paint window when finished.

Note
You can review the other Jiggle attributes on the cMuscleSystem node in the Channel Box or Attribute Editor. See Jiggle attributes in the Maya Muscle guide for more details about each attribute.

The basic leg rigging is now complete. You can find the completed file for this lesson, DragonLeg_Jiggle_End.mb, in the Maya Muscle Advanced Techniques folder.

Note

Since the Jiggle calculations for per-point skin jiggle can use significant machine resources, you can use Muscle’s per-point cache feature to provide faster animation playback during operations like lighting or rendering. In the next steps you cache each frame of animation internally on the node in the Maya scene itself. This way you can cache playback, then playback within Maya for faster speed and interaction.

Create a cache

Select the skin mesh object.
From the main menu, select Muscle > Caching > Create Cache.
The frame range is the current Time Slider range, and the cache data is stored within the Maya scene. Leave the default options in the Generate Cache dialog that appears.

Note
In this lesson you use node-based caching, however if you are planning on using external file-based caching, you can set the path and base filename using the Attribute Editor, or by selecting Muscle > Caching > Set Location of Cache File from the main menu.
Make sure your skin mesh is still selected and click Generate Cache for Selected Objects.
A progress window appears as the Time Slider scrubs and the cache is calculated.

Once the dragon leg animation is cached, you can have faster playblasts, or change camera angles and playback to see how the animation looks from different angles. Since the data is cached, deformation is not really being calculated, making playback faster.
Playback the animation.
Depending on the speed of your computer, the cached animation plays back in near real-time. The cache attributes on the cMuscleSystem node (which can be seen in the Channel Box or Attribute Editor) shows that the cache is now set to read-node. This means it is now reading the point cache rather than doing full calculations.

Note

While you are viewing the cached data, attempting to change settings (such as turning Sliding deformation on or off, or attempting to paint weights) will have no effect on the mesh.

To remove the cache

Do one of the following:
- Select Muscle > Caching > Delete Node Cache, then select which frames to clear.
- Switch the cache attribute of the cMuscleSystem node to disabled.
  This disables caching and returns to the normal calculation.

Beyond the lesson

In this lesson you learned how to:

Set up Jiggle deformation
Paint Jiggle weights
Set up a per-point cache to facilitate faster playback

You can find the completed file for this lesson, DragonLeg_Cache_End.mb, in the Maya Muscle Advanced Techniques folder.