Requirements
In this homework, we were tasked with testing rigs or watching Pluralsight tutorials on rigging human-like characters. Then describe
three methods or tools I learned about and found interesting with screenshots and text.
Readme
I chose to watch Pluralsight's online tutorial "Blend Shape-Based Facial Rigging in Maya" which covers many interesting and useful techniques and skills for rigging a human face.
The first technique I learnt is how to re-weight the base joint of the tongue through Component Editor in lesson 5. By setting all the weights of the root joint (bind_tongue_a01) to 1.0, we can stick the base position to its bind pose. Fig.1 is a screenshot of the Component Editor and Fig.2 compares the effects before and after this operation. We can see clearly the difference between poses of the root joint on the tongue.
Fig. 1, Screenshot of Component Editor
Fig. 2, Comparison of tongue pose
The second thing I learnt from this tutorial is placing an object at the center of another using Python script introduced in lesson 7. The underlying Maya tool used is parent constraint, but here we invoked a Python script to do the same job and wrapped it as a tool icon in Shelf. The Fig. 3 below is a screenshot of the Maya UI in which we can see the script in Script Editor, the settings of the Shelf Editor and corresponding tool icon in the Rigging Shelf, as well as the result after clicking the tool icon -- the locator was moved to the position of the character's pivot. Note that I adjusted the order of selection to comply with the convention of constraints, i.e., selecting the target first (sel[0], the character) and then the object to be moved (sel[1], the locator).
Fig. 3, Maya screenshot for creating a Shelf tool to align objects using Python scripts (click to enlarge)
The third point that interested me in this tutorial is adjusting the order of input nodes so that the eyeball will not be exposed out of the socket. This is covered in lesson 8 of the tutorial. In the left sub-figure of Fig. 4 below, it is seen that the left eyeball goes out of the socket. In the original order, the free form deformer (or lattice) was evaluated before the skin cluster, so we need to reverse their order in the List of Inputs window. Fig. 5 is a screenshot of this window with correct order of input nodes. By changing the order (moving Skin Cluster below the Ffd with MMB-drag) following the tutorial video, I fixed this problem as shown in the right sub-figure of Fig. 4.
There are many other interesting tricks in this tutorial such as manipulating skeleton like segmenting or disconnecting joint chains, positioning joints to keep track of edge flow, resetting the orientation of end joint for right skinning, setting Joint Orient to 180 degree to flip the X-axis so that a pair of joints will rotate in an opposite direction, checking "Group base and lattice together" in the Lattice Options window to make sure the base will always follow the lattice, holding down Ctrl and move LMB horizontally to change values in the Attribute Editor, etc. I will not describe them in detail due to time limit.
Fig. 4, The problem due to incorrect order of input nodes
Fig. 5, The screenshot of Maya's List of Input window