UV Unwrapping - Blender Master Class: A Hands-on Guide to Modeling, Sculpting, Materials, and Rendering - page 112

Project from View This option projects your mesh
as it appears in the 3D Viewport. It's particularly
useful for projecting a small, flat part of your
mesh before pinning it and then projecting the
rest using the Unwrap operator.

loop at once, allowing you to mark multiple edges
at the same time. Shortcuts like these will make
tagging multiple edges at once much quicker.
In general, you should try to hide your UV
seams in areas where they won't cause problems
and where they will minimize the amount of
stretching in your unwrap. Valleys and creases in
your mesh are good places to hide seams, as is any
area that won't get too much attention. Try to mark
seams symmetrically to make it easier to understand
your unwrap and to allow you to copy and paste
elements of your texturing later (if your unwrap is
symmetrical, too). Finally, split your mesh into sen-
sible islands (groups of faces bounded by seams).
For example, in the case of the Bat Creature, I split
the torso, wings, head, arms and legs, and hands
and feet into separate sections, as you can see in
Figure 8-4.

Project from View (Bounds) This option works
like Project from View, but after it projects the
meshes, it stretches the UV coordinates to fill
the whole UV-coordinate space.

Reset This option stretches each face across the
whole UV-coordinate space.

Seams
Imagine trying to flatten out a beach ball. Even once
you deflate it, you can't stretch it out so that each
part of the surface is flat on the ground without
making at least one cut to the ball, and the more
you carve it up, the less you have to stretch and
distort it in order to flatten it
out. Something similar is true
when using the Unwrap opera-
tor to unwrap a mesh. In order
for the operator to work, you'll
need to mark edges as seams
where the mesh will split. Ideally,
you should mark as few seams as
possible so that you won't have
to paint across too many seams
when it comes to texturing, but
you also need to mark enough
so that your mesh will not be
distorted by the UV unwrapping.
Distortion in this case arises
from Blender having to warp and
stretch the geometry in order to
lay it out flat. When you use the
distorted UVs to map an image
to the 3D object, the texture will
look stretched out as well.
To mark UV seams, select
edges in Edit mode and use
ctrl -E 4 Mark Seam to mark the
edge as a UV seam. To quickly
select the shortest path between
two edges (a good way to select
a long string of edges for mark-
ing), select one edge, then press
ctrl and right-click the edge
you want to use as the end point.
You can also press alt and right-
click to select an entire edge

Figure 8-4: The UV seams on the Bat Creature are shown here in wireframe view.
While some seams are (unavoidably) in visible areas, such as around the outside
edge of the wings, most are hidden in less conspicuous areas, like the inside of the
legs and down the back of the ears and neck. Hiding your seams like this makes
cleaning up seams in textures easier later on.