Sculpting - Blender Master Class: A Hands-on Guide to Modeling, Sculpting, Materials, and Rendering - page 84

Figure 6-26: Adding an eye to make sculpting the surrounding areas easier and using the Crease brush to mark in key features
of the face. Remember when scaling the eye to the correct size that the skull is approximately five eye-widths across and that
there should be one eye-width between the two eyes.

for the eyeball (see Figure 6-26), then sculpt the
eyelids around the sphere. A Mirror modifier can be
used to create the other eye by using the body object
as the mirror object in the modifier settings.

Wrap modifier, and setting the original mesh as the
target. This can work reasonably well for simpler
sculpts, but for more complex objects, it can cre-
ate some artifacts and errors that will take time to
straighten out. As such, for more complex sculpts, a
better method is to use a displacement map.

Time to Retopologize
At this point, I had reached the stage where adding
further subdivisions would be slow and unwieldy with
the current topology (the polycount of the body at
this point is over 5 million faces). By retopologizing
at this stage, you can create a denser and more suitable
mesh that gives a higher initial density of polygons
in important areas like the face and hands, with bet-
ter topology to support the coarser details. This will
allow you to resume sculpting again after retopologiz-
ing and add finer details to the mesh without having
to keep increasing the poly-count to ridiculous levels.

About Displacement Maps

A displacement map is an image texture that defines
how to displace the surface of a mesh according to
the value of the texture: White areas cause the sur-
face to be raised, and black areas are pushed in. By
UV unwrapping the mesh and applying a displace-
ment map to the new mesh, you can transfer the
details of the old sculpt to the new mesh.
To create a displacement map, use Blender's
texture-baking tools to calculate the distances
between the surfaces of the original sculpt and the
newly retopologized mesh and to bake them into an
image. Then, by using the Displace modifier (com-
bined with the Multires modifier to subdivide the
mesh), you can apply this displacement to make the
new retopologized mesh exactly match the old
one. (UV mapping is covered more thoroughly in
Chapter 8 and texture baking in Chapter 10, so I
will only touch on the basics here.)
I created a simple UV unwrap for my retopolo-
gized mesh by tagging some seams ( ctrl -E) to split it
into easy-to-unwrap patches. Then I unwrapped it
using the Unwrap operator (U 4 Unwrap) and
packed the UV islands into the UV grid. (You can
do this automatically with the shortcut ctrl - P.)

* Jump to Chapter 7 if you wish to follow along in strict

chronological order. From here on, I will be transfer-
ring existing details to a new retopologized mesh before
moving on to add finer details.

Transferring Sculpted Detail to a New Mesh with a
Displacement Map
Having retopologized the sculpt, I was left with
transferring the details I had sculpted on the origi-
nal mesh to the new one. There are several ways
to approach this, each with its advantages and dis-
advantages. One way is to use the Shrink Wrap mod-
ifier: first adding a Multires modifier to your new
mesh, then subdividing a few times, adding Shrink