From ZBrush Info

Contents 1 Rigging 1.1 Step By Step 1.2 A few tips to keep in mind: 1.3 Preview your high-rez details on a posed mesh:

Rigging

Rigging in ZBrush is fast and simple. It is currently being redone to comply with subtools and reworked to give the artist more control over rotation and weighting. It works superbly for bends such as knees, elbow and chest, however, it does not give you control over rotations such as rotating a wrist.

To rig a model you start with the lowest (or at least a relatively low) subdivision level. You do not want to rig the highest subdivision level. The low resolution is rigged and posed. Then "preview" your high resolution mesh by going through a few steps that will all be automated in one of the next betas.

Step By Step

Let's look at the steps:

1. First, draw a ZSphere on screen and go into Edit mode.
2. Go Tool:Rigging:Select and select the mesh that you want to rig. Make sure that it is at a low level of resolution.
3. Create more ZSpheres by clicking on the ZSphere in the center. The positions of the ZSpheres are important but are not the only determiner for the effect on your skinning. Make sure that the root ZSphere is somewhere near to what is usually the center of gravity of the model--an area that doesn't bend sharply itself. For a typical humanoid, you will want a ZSphere below the root for the hip, and a ZSphere above it for the ribcage.
4. When your skeleton is completed, press Bind. ZBrush is using an automatic weighting solution so check your mesh to see if it is weighted correctly.
5. Pose your model using Rotate or Move. Press A to preview your low-resolution mesh in that pose.

A few tips to keep in mind:

• Arms should be around 45 degrees or more away from the body. Otherwise they can get caught up in the ZSpheres for the spine.
• If the weighting is not right, unbind the mesh by pressing Bind again (it should not be orange after this, i.e. it should be off) and try to reposition some of your ZSpheres. Press Bind once you are ready to test the weighting again.
• When you turn Bind off, your mesh returns to your bind pose.

Preview your high-rez details on a posed mesh:

1. Create your skeleton
2. Set Tool:Adaptive Skin:Density to the same number as the maximum levels of resolution for the mesh you are posing.
3. Press Shift and click on the Tool:Adaptive Skin:Preview button. This will preview your high rez mesh.
4. To have this happen every time you press A you have to sculpt some small brush strokes after you press Shift and click on the Preview button. If this step is not done or is undone you will not preview your high rez mesh. :div>:div>