ZBrush Character Creation - Advanced Digital Sculpting 2nd Edition

■ Generating Displacement Maps 313

Making 32-Bit Floating-Point Maps

There’s an added benefit to creating a 32-bit map; it carries real-world scale baked into the
map. This allows you to create more accurate and detailed renders in software that can han-
dle such large maps.
When you create 32-bit maps, you use the same menus that you do when creating 16-bit
maps, but you have access to a few more options and a different button to generate and export
the map. Had we wanted to create a 32-bit map in the previous exercise, we would have
enabled the 32Bit button under Tool → Displacement Map.
You can export 32-bit maps from ZBrush but you cannot reimport them. Further, you
cannot display a 32-bit map inside ZBrush. This is because the maps carry so much detail
and information that ZBrush cannot display them in real time. Once you generate a 32-bit
map, it is immediately exported to the hard disk for use in an external renderer.

The 32-bit floating-point maps generated in ZBrush should not be edited in an external

editor—doing so may alter the map in undesired ways.

Follow these steps to create a 32-bit floating-point displacement map:

1. With your ZTool at the lowest subdivision level, choose Tool → Displacement. Select
   any alpha in the preview swatch so that all the options in the window become active. In
   the Displacement settings enable the following buttons: Flip V, 3 Channels, and 32Bit.
   Also set the Mid slider to 0.


2. Click the Create And Export Map button. ZBrush will prompt you for a file save loca-
   tion and filename.

The importance of having real-world scale baked into a 32-bit map is to simplify the ren-

dering process. Sixteen-bit maps record only that one point is higher than another point;

32-bit maps record the relative height of the highest point and depth of the lowest point

in relation to the overall scale of the object. This means that your settings in Maya will

remain consistent for all 32-bit displacement maps you render. At the same time, 16-bit

maps require some rescaling of values to achieve proper renders.

Multiple Maps per UV Region

In instances where you have multiple UV regions for a character, you will want to generate
maps for each part. To do this, simply generate polygroups based on UV region by choosing
To ol → Polygroups → Auto Groups With UV. This will create polygroups for each UV region.
Ctrl+Shift-click to hide other regions and generate and export a map for each part at a time.

Displacement Menu Options

We have already used the displacement menu to create a 16-bit map. Let’s now take a closer
look at the options in this menu and what they mean (Table 9.1). Figure 9.30 shows the menu
with various callouts to the function of each button. Please see the accompanying DVD for a
video concerning this menu and some unique functions available in it.