Blendshapes workflow in Maya

Creating blendshapes can be a lot of fun and lot of frustration.
We need to take care of a few simple things to make sure that the blendshape process goes smooth.

I have done a few blendshapes till now, and by few I really mean 2 🙂
but these 2 exercises have been enough to teach me quite a lot about blendshapes.

I will be putting up a video of the blendshapes soon and will share the link then. For now, lets focus on the simple golden rules.

1) Vertex based deformation. Blendshapes work on a vertex basis. So, if i duplicate my characters face, and move it and create a blendshape, nothing is going to happen. Instead, if I duplicated the face, went to component mode, selected all vertices and moved the face to a new position and then did a blendshape, the base head would move to the destination heads position when blendshape is activated.

2) Overlapping areas. Be very careful about the areas/vertices that will be influenced by a blendshape. Otherwise, you will be surprised how when the mouth is already opened and you move the eyebrow, the cheek ends up deforming weirdly.

3) blendshape node and skin cluster. open up your blendshape option box, go to advanced, and make sure the option is ‘INFRONT OF CHAIN” and make sure this is turned on.

4) naming. If your target head is Head. and you duplicate this head 60 times to create 60 blendshapes, and fail to name them, you are going to have fun telling me what head47 does. how about what the face will look like when I activate head47, 53 and 33? You get the idea.. each time you duplicate the base head to create a blendshape, Name it.

5) FreezeTransform. Do this on your base head BEFORE beginning you blendshape process. and Always make a duplicate of this base face and move it in world space and name it as a new blendshape and then start working on the shape itself. NEVER do a freeze transform on the blendshape head. You sever all ties with FreezeTransform button once you start the blendshape Process.

6) STAY AWAY from FREEZE TRANSFORM. Really!!!

7) Nodes. When you create a blendshape, it creates blendshape nodes. It’s also good to name these nodes. Now, if you create a blendshape node for Smile. And create a new node for Frown. And try to activate both, only one of them is going to work at the same time. Workaround? There are 2 options.
a) You will create only ONE node for each type of geometry. What I mean by that is the entire face geometry should have only ONE node. All the blendshapes should be feeding into this ONE node. You can go ahead and create another node for Teeth, another for Tongue and so on. But, never two nodes for the same geometry.
b) When you go to createBlenshape window, under Advanced tab, look for deformation order pull down list. Set it to Parallel.

8) mirroring shapes. Never mirror your left eye blink in z axis and expect it to become right eye blink. The reason is each vertex is given a number in maya. If you go to component mode and select a vertex, you should be able to see the vertex number in script editor. These numbers are what drive the blendshapes. If you mirror the shapes, the vertex numbering does not change. So, maya will still see vertex292 going up/down. There are scripts to do the mirroring. Look for ntMBS in highend3d and you should be able to get the shapes mirrored easily.

I guess that is it. I am working on my 3rd blendshape now and as and when I find more stuff, I will add it here.

I will add more posts under the page Blendshapes. It will be a tutorial on my blendshape workflow.

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