ZBrush Character Creation - Advanced Digital Sculpting 2nd Edition

■ Setting Up Your Scene for Displacement 321

Rescaling Objects

You may discover if you rescale an object with a 32-bit displacement map applied, the displace-

ment will no longer render correctly. This is because real-world scale is baked into the displace-

ment map. You can correct for this by changing the Alpha Gain setting under the Color Balance

options of the fi le node. If you change your object scale, set the Alpha Gain value to the same as

the scale of the object. This will automatically correct any values read from the displacement to

render accurately for the new object scale. If you need the object scale to change over time, this

setting can be driven with an expression.

For Alpha Gain, type in the following expression, replacing objectname with the name of the

mesh in Maya:

=​​objectname.scaleX

Alpha Offset will remain at 0.

Be sure to begin the line with the equal (=) sign. This ensures that the Alpha Gain value scales

with the object scale.

Figure 9.37 The output window: this mesh was divided to 452,932 triangles or 226,466
faces at render time.