Rigging is the process where a 3D model is given some sort of skeleton so that it can be posed. In ZBrush this is done using a ZSphere structure.
ZSphere Rigging Step-by-step
- First, draw a ZSphere on screen and go into Edit mode.
- Go Tool > Rigging >Select and select the mesh that you want to rig. Make sure that it is at a low level of resolution.
- 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.
- When your skeleton is completed, press Tool > Rigging > Bind Mesh. ZBrush is using an automatic weighting solution so check your mesh to see if it is weighted correctly.
- 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 Mesh again (this should turn off the switch so it is not orange) and try to reposition some of your ZSpheres. Sometimes adding extra ZSphere chains that go to specific points on the model can help control the way the mesh deforms. Press Bind Mesh once you are ready to test the weighting again.
Previewing your high resolution details on a posed mesh:
- Create your skeleton as outlined above.
- Press Tool>Rigging>Bind Mesh.
- Set Tool > Adaptive Skin > Density to the same number as the maximum levels of resolution for the mesh you are posing.
- Press Shift and click on the Tool > Adaptive Skin > Preview button. This will preview your high res mesh.
- 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 res mesh.
- Now go ahead and pose your model. Anytime you want to preview the high resolution mesh, just press A.