8

608 Chapter 8: Modifiers
4.
In the material’s Maps rollout, click
the Displacement button, then use the
Material/Map Browser to apply a displacement
map.
Inter face
Subdivision Displacement—Subdivides mesh faces
to accurately displace the map, using the method
and settings you specify in the Subdivision Presets
and Subdivision Method group boxes. When
turned off, the modifier applies the map by moving
vertices in the mesh, the way the
Displace modifier
(page 1–608)
does. Default=on.
Split M esh—Affectstheseamsofdisplacedmesh
objects; also affects texture mapping. When
on, the mesh is split into individual faces b efore
displacing them; t his helps preserve texture
mapping. When off, texture mapping is assigned
using an internal method. Default=on.
Tip: This parameter is require d because of an
architectural limitation in the way displacement
mapping works. Turning Split Mesh on is usually
the better technique, but it can cause problems for
objects with clearly distinct faces, such as boxes,
or even spheres. A box’s sides might separate as
they displace outward, leaving gaps. And a sphere
might split along its longitudinal edge (found in
the rear for spheres created in the Top v iew) un less
you turn off Split Mesh. However, texture mapping
works unpredictably when Split Mesh is off, so
you might need to add a
Displace Mesh modifier
(page 1–499)
and make a snapshot (page 1–438)
of the mesh. You would then apply a UVW Map
modifier (page 1–905)
and t hen reassign mapping
coordinates to the displaced snapshot mesh.
Subdivision Presets and Subdivision Method
group boxes
The controls in these two group boxes specif y how
the modifier applies the displacem ent map when
Custom Sett ings and Subdivision Displacement
are both turned on. They are identical to the
Surface Approximation controls (page 1–1241)
used for NURBS surfaces.
Displ ace M odif ier
Modify panel > Make a selection. > Modifier List >
Object-Space Modifiers > Displace
Make a selec tion. > Modifiers menu > Parametric
Deformers > Displace
The Displace modifier acts as a force field to push
and reshape an object’s geometry. You c an apply
its variable force directly from the modifier gizmo,
or from a bitmapped image.