|Maya 7 includes some nice additions to the animation toolbox.
Last time we took a look at the Full Body IK animation system. This
time I will show you something nice about the BlendShape deformer.
If you've worked with Maya deformers, you know that some of them,
such as bones or clusters are told which vertices to affect using
weight maps. Now you have the ability to use weight maps for the
BlendShapes. Painting on the right spots you can turn a full smile
into a half smile, or even a "part-lips" morph. After you've
modified a BlendShape with the paint weights tool, you can save it
as a new morph. This is a powerful way to make new morphs for your
character. Not only can you create new BlendShapes on the fly, but
you can also get rid of that horrible symmetry that animated
characters often have (for example, make the brow deform slightly
different on one side, or make the mouth open wider on one side).
The best of all is that the BlendShape weight maps can be animated,
which opens a lot of possibilities.
morph applied to the figure ]
One of the biggest challenges about facial animation is to get
organic deformations on your character's face. In Maya there are
some workarounds for this. You could use a joint-based facial rig
to simulate muscles deforming the skin, or you could use
in-betweens for your BlendShapes. Now in Maya 7 you can use the
Paintable weight maps to gradually affect your mesh with the morph
and thus obtain a more organic deformation. Our skin is
deformed by muscles, and, as you know, they do not deform in a
linear way. For example, when a person smiles, the mouth is the
first thing to move, followed by the cheeks. Say you want to
reproduce that in Maya using BlendShapes. Simply animate the morph
as you would always do, and then open the BlendShape paint tool,
paint a bit and hit the "key" button, move along the timeline,
paint again and key again, and so on until you've applied the full
morph. You can even use this for full body morphs, if your computer
can handle it. Surely you remember that effect shot in the
Xmen movie when Mystique morphs into Wolverine. They
actually used animated BlendShapes for that scene. Using some MEL
scripting they linked a weight map to a full body morph on
Mystique's digital-double and then they animated that weight map.
That was done on Maya 3, I think, but now you have the ability to
do that right out of the box thanks to the animatable weight maps.
Use the weight maps to make your fine lady "melt" into a big demon.
Rig a couple of wings that will grow out of his/her back and you
have a very nice effect. You can even use them to morph any kind of
objects. Maybe you can gradually morph a mountain into a large
chasm or something like that.
Morph's weight map set to 0 ]
Painting the weight map to gradually add the morph ]
This tool is extremely nice and it allows you to do a lot of crazy
effects, but there is a downside: depending on the resolution and
complexity of your mesh you will not be able to use the animated
weight maps. I tried to use them to make a melting effect from
Victoria to Michael, and Maya would hang every time I tried to
animate the maps (my system specs are: AMD 2700+ / 1Gb ram /
GeforceFX 5200 ). On the other hand, for simple things such as
facial expressions it worked just fine. This means you won't be
able to do some really cool effects unless you have a top-of-the
line system. Maya has been known for its innovations, and version 7
really shows us why. The improvements in the animation system alone
are worth the upgrade. Nevertheless, Maya includes several
improvements on other areas. I encourage you not to take my word
for granted. Download the free Maya 7 PLE from Alias and
experience the power of 3D.
Animation Alley is a regular featured
column with Renderosity Staff Writer Sergio Rosa [nemirc].
January 16, 2006