Rigging is now complete on my bird nosed goblin character this was the lengthiest process so far and I have learned a lot.
using the joint tool and the ‘snap to projected center’ option you can create a skeleton for your character, personally I found starting at the feet and moving up was the easiest way, you also only need to focus on 1/2 of your model as duplicating joints to the other side of your model is a simple way to keep symmetry.
First step was to learn about joint orientation and IK handles which influence the joints in between to main joints, for example if you created an IK by selecting the ankle and hip joint when the joint in between (the knee) gets moved as well.
A small issue I found while doing this was the knee bent at a undesired angle, this is fixed by rotating the un-skinned joint at the desired bend angle, right click over the joint and choose the ‘Select Desired Angle’ option which when skinned and moving the IK leg the knee bends at the correct angle. This is caused by improper joint orientation.
Joint orientation makes sure the joints rotation axis doesn’t move in a strange way when animating and requires less work when animating.
Making controllers is a surprisingly simple process, you can create a NURBS shape and after making sure the shape is centered to the desired joint you can parent the joint to the controller which allows the limbs to be moved and rotated then easily set back to the original position without changing the orientation of the joint itself. and provides a easier interface to animate with.
Advanced Skeleton 5
Advanced Skeleton 5 is a in-depth auto rigging plugin for Maya that can produce a high quality rig with controllers for almost any kind of character.
I used advanced skeleton to rig my goblin character, understanding the basics of how the rig worked was helpful in following the steps correctly as there are a lot of potions available.
My first attempt was to add extra bones to the ears to allow when to move when the character was moving.
Advanced skeleton even created controllers for the added joints which worked quite well however the weights on the ears meant it would take a lot of work to weight them correctly to allow them to move without influencing the rest of the face, I ended up using blend shapes for this task later which will be expanded upon.
Some of the controllers as you can see in above screenshot meld into the mesh making them hard to select, by holding right click over the object and selecting ‘hull” mode and then again left clicking on the shape again you are able to scale and move the controller without affecting the joints rotation or movement.
Since I have my eyes and teeth as separate objects this can be connected to the skeleton by skinning the extra objects under the deform options, this also allows them to be selected later in the Face Rig Menu
Make sure to delete the history of your mesh before binding the skin to the skeleton. I had to redo my weight painting as deleting history removes any painted weights.
After skinning my character I found that there were unwanted deformations when moving joints such as the hip bones, under the arms and the head would stretch if the arm moved, this was all fixed by painting weights on my character.
Since my character is a bony guy I wanted to make sure that they did not stretch much if at all, the only problem was with weighting the head as weighting the wrong joint resulted in weird stretching if the neck was rotated.
Face Rig / Topology
I first tried to rig my face using the Advanced skeleton plugin, but since my topology had incomplete edge loops where I needed them I decided to re-topologize the head and re-attach to the body
I encountered an error where Maya did not like my AMD Ryzen Processor when unfolding the UV, I had to use my laptop to unfold and then bring it back onto my main computer hopefully this is something Autodesk can fix in the future, I will have to pop into substance painter to make sure my texture fits the new head without stretching, this shouldn’t be a huge issue.
With the new topology in place I tried again to use the facial rigger within Advanced Skeleton 5 however the results weren’t ideal and with not wanting to waste time learning the plug-in for now I decided to create blend shapes and connect them to controllers.
I created a few blend shapes with the Shape Editor and used the combine target and in-between targets to get them to look how I liked, I also used blend shapes to make the ears move up and down which I can keyframe during animation if I like.
I then used the set driven key to connect the blend shapes as the driven to a NURBS shape which acted as the driver, I then assigned a expression to X and Y values both negative and positive to create a slider box that when moved was able to merge between the 4 expressions, I later changed this to be in the Attribute editor under the head controller as I thought this would give more freedom, I also ended up only having a open and close mouth movement as I felt it was not necessary to have to many for the animation I am planning.
Since the teeth were a separate object I used a blend shape to move all of the vertices down and back to match the movement of the jaw and set the same driven key as the open mouth movement.
Knowing how to add attributes to a controller is a very useful tool.
as of now I am happy with the rig and can now move on to adding clothing and animating the model.