|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.
[ A 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.
is a regular featured column
with Renderosity Staff Writer
Sergio Rosa [nemirc].
January 16, 2006