When we have the basic shapes and polygroups, it's time to pose the character. But before doing that, make a few screenshots and draw the muscles in. This is one of the exercises that Scott Eaton covers in his Anatomy for Artists course. It helps you to see and understand if the anatomy is in the right place, but it is also fun. I like to do this every time I get the opportunity (Fig.07
Looking at the sketch, he needs a boxing jersey. The way I like to make one is to draw the topology onto the mesh and use the topology brush to create the geometry:
1. Duplicate the body mesh, delete subdivision levels, fill white and draw red lines
2. Smallest size, double click, hide body, delete hidden
3. Extrude, UV Master, Noise Maker, don't bake.
Most of the fine detail appears in his face and the resolution does not have to flow down to his body.
At this point we can make two separate subtools out of them. The cut will be covered by his jersey. The boxer jersey is slightly different from the original, because I don't have my saves for this part. However, the techniques I describe are the same.
I like to sketch my topology before I start drawing the new mesh. With the Standard brush selected, turn off the ZAdd and make sure RGB is turned on. From the Color menu, pick a white color and hit the FillObject button just under the RGB sliders. Next, hit the SwitchColor button and select a bright green color to sketch the topology.
White is now the alternate color that we can use to erase the green lines when we need to make changes. By pressing Alt (Windows) or Option (Mac), you paint with the alternate color (Fig.08
When using the topology brush you need to freeze or delete the subdivision levels. Instead of working on the original ZTool, make a duplicate of the body and pick the subdivision level that still displays clear green lines. Next, delete its higher and lower levels.
Now simply trace the lines. If you need to cross a few lines, just make one sweep across them. When you go a bit beyond the lines, a little green circle appears - this mean ZBrush could make a vertex at the cross section. It doesn't really matter if your lines are not straight, because the polygons are created between the cross sections/vertices.
You can clean up the topology lines by simply hold down the Alt key (Option key for Mac) and drawing a little horseshoe somewhere on the model (Fig.09
If you couldn't finish a topology line all the way through, then move closer to the end of that line. Your brush turns blue, which indicates that you can continue working on the topology lines. Now simply drag the line so you can create a new polygon (Fig.10