Game Development Reference
In-Depth Information
Why?
Making Aegis a single mesh in this situation has several benefits. First,
the plan is to have Aegis simply in an idle animation as an introductory
level for the game. The animation will be simple and he won't be holding
any of his weapons. By reducing Aegis from six meshes to one we are
reducing the number of draw calls required to draw him in this animation
because Unity only has to draw one object (although this object has
several materials on it) instead of six. Further, joint deformation within
Unity is a fairly expensive process. Every mesh that needs to be deformed
costs processor cycles. So while we could skin all six objects to the same
single joint structure, we will further optimize playback by having only
one object deformed by that joint structure. Plus, the actual skinning
process will be easier working with this single mesh.
Finally, saving as a different file name keeps the old version where Aegis is
separated into his component parts.
Joints and Rigging
Generally, students intuitively think of placing
bones
in a character, and then
the idea is moving the bones moves the character; in this paradigm, joints are
just where the bones happen to meet.
Joints
are a little bit different way to
think of moving a character. Maya makes the joints the important part and the
bones simply visually connect these joints.
At its core, a joint is a
deformation object
, which means it can be used to deform
another object, or more importantly,
parts
(including polygons) of another object.
The work flow is reasonably intuitive: first, these joints are created and placed
within the polygon mesh. Then, after these joints are bound to the mesh, when
they rotate, the polygons that are skinned to those joints rotate with it.
There are a few things to remember about working with Maya's joints that
will make working with them smoother. First, every bone has a joint at its start
and end. This means that there will be joints at places that may seem a bit
strange, like the tips of the fingers and top of the head. Second, when placing
joints, as long as you are still in the Joint tool, each joint will automatically
orient to point to the next-placed joint. This is good in some cases but
problematic in others. Third, we want to make sure we're working smarter, not
harder. This means we will only be creating one half of the skeleton and then
have Maya figure out the other half. But to make this happen smoothly, we
need to place joints in specific view panels; some will need to be placed in the
side-view panel, others specifically in the front. Although joints can be moved
and reoriented, if we simply place them in the right-view panel, some things
(like being placed on the mirror plane) will automatically happen.
Step 14:
Switch to a four-view setup. Do this by either pressing the space
bar quickly (
Figure 10.3
) or, if you have other nested windows, by choosing
the four-panel preset from the view panel presets beneath the Toolbox
(on the left side of the interface).
