Week 7 – Character Rigging – Advanced Experimental Animation Unit

Unit 2.1 Advanced and Experimental 3D Computer Animation Techniques – Project 1, week 7.

Eyeball Rig Test

There were a few videos that produced complex eye rigs, however I wanted something quick and simple. While I had trouble with the eye rig many times while attempting to complete the rig, this video was the most useful and appropriate to my project.

Figure 1. (Maya Rigging Tutorial – Eye Control Setup, 2017).

My Eye Rig Practice

Figure 2. My eye rig test.

I tested the method to rig eyes before making the rig myself.

Rig Attempt 1 – Manual rig

The rig I made manually from the start was a decent enough effort, however, after consultation with the teachers professionalism, it was not enough to animation properly. I had placed the pivot points for some controls in the wrong place. And I have yet to fully understand how I should rig faces. Therefore, at this stage, it was better for me to save the feedback from manual rigging in my mind and learn to make a rig using advanced skeleton, for a more usable rig.

Reference

Figure 3. (3DArt_house, 2021).

My Complete Rig

Figure 4. Rig version 1, manual rig completed.

Eye Rig Problem

I had much trouble with my eye rig. I took inspiration from one video to make arrows for the individual eye controls. I followed the instructions by using aim constraint on the individual eye control to the eye joints, then parenting these controls to the main eye control. There seemed to be an issue with the aim constraint not working. The eye was not following no matter which tutorial version I tried. I believe I have found the issue, I restarted the individual eye controls (circles instead of arrows) and placed them at the position of the main eye control. The issue I discovered was that the individual eye controls needed lateral translations for the aim constraint to work, however, I had placed the pivot point of my arrow constraints at the position of the eye joint and used rotation. This is where I went wrong. See the images below.

Facial Rig is Incorrect

After some tutor feedback, I realised that the facial rig was incorrect. Most importantly was the lack of joints connected to the end joints and the locations of the controls’ centre pivots. Basically the jaw, eyebrows and eye lid END joints were all children of the head joints. Where as the correct way to do this, using the jaw as an example, is to have a joint where the jaw rotates from and then an end joint. Then the control will rotate (rotate only) from the first joint. Where I would have used translation instead of rotation in order to animate the jaw. Not that I plan to use the jaw very much, however, this was still incorrect, and essential for me to learn.

Figure 7. Jaw pivot point principle. The same principle will work on humans or dogs (Evans, 2016).

Correct way to rig the jaw:

Rig Attempt 2 – Advanced Skeleton Plugin

After all of the trouble I went through when I manually rigged, I had an issue with the advanced skeleton rig. After consultation with my tutor, I realised it was something silly. Still, this set me back a few days. Additionally, when weight painting, the weights seemed to change often after I edit them. I implemented the locks in the weight painting tool bar in order to fix any issue. That way, I was able to more closely manipulate the weight locations.

Issues with the Rig

There was an issue with the eye controls. When using ‘advanced skeleton’, there was no main eye control to move the eyes together. I tried to parent a control to both eyes, however, this did not work. The aim of the eyes became a translation instead. I left it as it was in case I caused any more issues.

Problems with the controls, when I first build the advanced skeleton the controls were not appropriately resized according to the model (see image below). I had to manually resize them and I had to leave some of them overly large. The reason for this was so that they could be seen outside of my mesh, and my limbs are quite large and compact, so some overlapped in each others ‘territory’ to much. This may not be the most convenient solution to the issue, nevertheless, the result is suitable enough for my to be able to animate with.

Weight Painting

I have methods to lock all joint layers in the weight painting tool bar and unlock only the ones that I want to transfer between. Since otherwise the system will transfer the weight onto joints that it dictates instead. This doesn’t always work. And I always have to smooth the weight afterwards with all joint layers unlocked. While this method works (usually) it is tedious, time consuming and I often have errors saying ‘cannot transfer because values are locked’ or something like that.

Method/Strategy

the face usually has misplaced weight everywhere, and if I simply remove the weight from one joint, the weight may be placed somewhere I do not want. My solution to this is to remove all of the weight from the face and place it on the head joint. Then add weight to my chosen joint one at a time. While this may take more time, I am able to more accurately place my weight.

Rigging Play blasts

Figure 13. Showing the rigs and tests with play blasts, both versions.

Rigging issues

I had to restart the rig about 4 times due to system or rig errors. As well as the last time when I received feedback from my teacher on my own rig and decided to use the Advanced Skeleton plugin to make a more professional and technically accurate rig.

References

2017. Maya Rigging Tutorial – Eye Control Setup. Available at: <https://www.youtube.com/watch?v=8EUKYkZMlww> [Accessed 26 March 2022].

3DArt_house, 2021. Rigging Method on Maya for Dog Figure. Available at: <https://www.youtube.com/watch?v=BiR1bUZEFCU> [Accessed 26 March 2022].

Evans, C., 2016. The Jaw. [Blog] Stumbling Towards ‘Awesomeness’, Available at: <http://www.chrisevans3d.com/pub_blog/the-jaw/> [Accessed 6 March 2022].