■ Details and Layers 153ZBrush 4 has the added benefit of allowing you to paint into HD geometry and then
extract that information into a color map. This allows you to work with literally billions of
polygons when you want to detail or paint your work. We will use HD in conjunction with the
Bump Viewer material to paint a bump map. If you use the ZBrush plug-in Multi Map Exporter
to extract your color maps, you can break up this bump map into multiple UV regions. For
more information on this process, see Chapter 9, “Normal Maps, Displacement Maps, Maya,
and Decimation Master.”
The Bump Viewer material is available under the Standard Materials menu. The mate-
rial reads a grayscale color value and displays it as a bump or recess. Using this material, you
can paint on the model in grayscale but see your strokes as if you were sculpting. Because
of this, I will refer to painting in this section even though we are seeing sculpted strokes.
Understand that ZBrush is interpreting a grayscale value and showing you a bump or val-
ley. In reality, you are applying grayscale color values as you work with this material. On the
DVD, you will also find a video demonstrating the Bump Viewer material in use.
The Bump Viewer material will work with polypaint, but if you are unable to divide to
a high level, the results will not be satisfactory. The following steps show you how to use the
Bump Viewer material to sculpt a bump map:
- From the accompanying DVD load the file fishguy.ztl. Draw the tool on the canvas
and enter Edit mode. Open the main Material menu and select BumpViewerMaterial
(Figure 4.71). - Enable the Polypaint feature by clicking Tool → Polypaint → Colorize. The model is
now ready to accept color. If you decide to use HD geometry it will not support layers,
so be sure you have baked all your layers before you proceed. If you choose to paint
into standard subdivision levels, divide your mesh as high as possible and create a new
layer for polypainting. For more information on separating color passes with layers,
see Chapter 5, “Texture Painting.”
Figure 4.71 The character ZTool with the Bump Viewer material applied