ZBrush Character Creation - Advanced Digital Sculpting 2nd Edition

242 chapter 7 ■ Transpose, ZSphere Rigging, Retopology, and Mesh Extraction

Two approaches are available when you’re importing topology from outside ZBrush. The

first is to import the new topology directly into the original ZTool. ZBrush will automatically

replace the lowest subdivision level with the new mesh. The second method is to import the

new topology directly into the Retopology tools and use ZBrush’s Project feature to re-create

your ZTool with the new topology. The last method is to use Project All and project the new

mesh over the original like a shrink-wrap. In this section we will look at these approaches.

Importing Topology into the Retopology Tool

We’ll look at an example where we just want to change one aspect of the low-res mesh. We’ll

export the original level 1 topology from ZBrush and reproject it in ZBrush. This technique

will work for an entire rebuild of topology as well.

1. From the Tool menu, load the original ZTool as well as the low-resolution rebuilt mesh.
   Figure 7.37 shows the original mesh that we want to change to remove triangles and
   redirect edge flow, and the reworked low-res cage built in Maya.

Figure 7.37 Original topology and topology imported as an OBJ and loaded

2. Draw a ZSphere and enter Edit mode. From the Rigging menu, select the original ZTool.


3. Under the Topology menu, click the Select Topo button. This will open the
   Tool palette and allow you to select the imported low-res mesh and convert it to topol-
   ogy. Select the low-res cage and click Edit Topology under the Topology menu. This
   will load the imported mesh as topology and allow you to further edit and project the
   mesh to the original ZTool (Figure 7.38).


4. Using Alt-click, delete some edges by clicking the points. These can be redrawn as
   desired (Figure 7.39).


5. When you are ready to generate a new ZTool, follow the same procedure as before: set
   your adaptive skin density and turn on Projection. Then click Make Adaptive Skin to
   generate a new ZTool.

Project All and the ZProject Brush

ZBrush offers other options for transferring sculpted detail from one mesh to another. Importing

topology as shown earlier is one of the more difficult approaches. If you have a low-res mesh you

want to project onto an existing ZTool and you don’t need to further edit the topology, you’ll

find an option under the SubTool menu called ProjectAll that makes this simple.