3D rigging is the process of creating a skeleton for a 3D model so it can move. (source) Once a creature/human model is done. Rigging is necessary because then the character can be posed to record animation. I found it is surprisingly easy to rig in zbrush using zsphere (unlike Maya, which I had hard time). This blog I used the model I made for the class to show the process of rigging in zbrush.
- First click the zsphere subtool located on the right panel
2. Then use zspehre to draw many zspheres and form bones and joints. There’re 208 bones in human body but it’s not necessary to model 208 bones for your model. Depending on which part you need to move, more or less bones should be added, but as a guideline, it should be like the following pictures. Otherwise the move of limbs would distort the torso. You may find the need to add bones to fingers and face if you want to do more detailed animation.
3. press Tool–Rigging–Bind Mesh.
4. Now you can pose you model!
5. To preview, set Tool–Adaptive Skin–Density to the same number as the subdivision level of the model
6. Press Shift and click on the Tool–Adaptive Skin–Preview button.
(source)