Proposal: Facial Rigging with shape keys
- Standalone Project
- 24 February
- 6 min read
- 10 min watch time
Over the years of animating on numerous films and projects, I’ve worked with different rigging techniques to create expressive faces. Each character required their own personality, style, and shape language, and therefore, their own rigging structure. At Blender, most recent facial rigs use a combination of facial bones, corrective blendshapes, and additional deformers. Bone-based rigs have their advantages but can become complicated when combined with action constraints, shape keys, and other drivers to achieve a specific deformation.
My experience as a lead animator at Sony Imageworks and a teacher of the 'Facial Animation' course at AnimSchool gave me the opportunity to dive into the process behind their facial rigs. I came to the conclusion that, in order to achieve specifically designed shapes, it’s best to minimize computer interpolation and instead have them designed by an artist. Looking at the animation industry over the past 10 years, the overwhelming majority of feature film facial rigs use the same method: a lot (and I mean a really lot) of blendshapes, or what we call shape keys.
This is by no means the only way to rig a 3D character’s face, considering the wide range of styles and approaches to facial rigging. However, improving this particular workflow in Blender could greatly benefit many animation studios and riggers. Ultimately, I would like to create a Facial Rigging course on studio.blender.org to provide studios and individuals with a solid foundation to build upon. This would involve improving the current shape key system, enhancing quality of life features, introducing more dynamic operators, and developing new tools to streamline the shape key-based facial rigging workflow.
This is a proposal for Blender Studio, as well as the community to respond to in order to gage the need for such an investment. Therefore we would love to get your input on this topic and hear from you if this would be something that would help your rigging workflow as well. Let your voice be heard by placing a comment at the bottom of this article, we’d love to hear from you!
What is Shape key Based rigging?
Shape Key based facial rigging consist primarily out of multiple connected shape keys and corrective shape keys that neatly blend together resulting in dynamic and designed facial deformations. These shapekeys are manipulated by control bones connected to individual vertices and are linked through drivers (with expressions), triggering one or multiple shape keys at once in order to reach the designated deformation. The animator moving the bone in 3d space is actually an illusion, it is bound to the mesh which is simply triggering shapekeys and seem like it is moving in space. This allows the rigger to combine infinite amount of shapes while the bones are following correctly.
The method of creating shape keys is duplicating the face mesh and creating designed deformations on this. In order to create a smooth transition between the different shapes (for example the mouth corners, a temporary armature is created in order to generate the range of motion on the initial mesh) Parts of the face like the lips, cheeks and brows are using a single deformation bone to create the range of motion (positive and negative in X, Y and Z) for the shape keys. this bone will be neatly weightpainted to the correct deformation area to create an organic and appealing deformation. Once this is established, I extract all key poses from the animated bone. This should get us 85% to the final shapes and can be tweaked, sculpted, masked additionally. Once these are looking good, the shape keys will be split into separate (local) shapes and assigned to its designated control bones. This process can be partially automated and will save a lot of time.
Additionally, Bones will be the foundation for the main structure and movement of the skull, jaw, eyes, eyelids/lashes, nose and ears. (and eyelids) as they are more static and in no need of heavily designed or complex deformation. Deformations are pre-designed by the rigger and approved by the supervisor so that the animator has a good foundation of setting up the expressions relatively easily without manipulating too many bones.
Control Bone Attachment to Mesh Vertices
To attach control bones to the face, we need to avoid dependency cycles. In order to achieve this, we use the Display Override transform. The hook bones are placed with a location constraint attached to a ‘single-vert’ vertex group. Now the bones are following the designated vertex location. The function of these hook bones are basically to drive the display location of the Control Bones which drive the connected shapekeys.
Proposal for developing a Facial Rigging course
Now, you might think this sounds like an old technique from the 2000s, but it’s still the standard at AAA animation studios. This is because of its artist-oriented workflow and the ability to effectively art-direct it in the early rigging stages. However, Blender currently does not support this workflow very well—at least not to the extent of managing and iterating a facial rig properly in a production environment in a non-destructive way.
I’d like to improve this by developing better tooling, enhancing the quality of life aspects of shape key implementation, and optimizing the way shape keys are stored.
Wow! You made it to the end of the article :D. I’m excited to implement a solid workflow like this for high quality characters in Blender. Would you like to see a course on how to make a shape key based facial rig with this workflow? Let us know in the comments below!
46 comments
Can't wait to see what you guys create. Question regarding the rig, Will it be able to be used in a game engine? lets say Unreal Engine?
@Sheldon J Smith normally game engines won't support shapekeys, so my guess would be no, but using alembic/USD might get you somewhere. But the focus for this project is high quality movie character rigging.
Yes, I highly support this! still waiting on it
Thanks . Could be great a detailed Tutorial. Any possibility to share one of these prototypes?.
@Carlos Puebla eventually yes, however right now i'm adjusting a bunch of fundamental things, so until i have a strong consensus on how to approach this workflow, i'll hold off to sharing files simply to avoid confusion :) I'll be posting a new blog once the project starts officially. There i'll be sharing files as i go and with a solid structure.
Absolutely man, you know it.
Yes - also, a section on GUI Controls seen here:
(1) Jerry Rig GUI (Maya) - https://youtu.be/OpIu9myNjm4?si=LMTBPnusQ3yMV7oU&t=9
(2) Maui Rig GUI (Maya) - https://youtu.be/-osWVmcRFXw?si=kb2H5bSzou0vgZDS&t=702
This workflow is extremely essential to any animation studio or freelancer using the software - I don't see any other topic coming before it. Even if Blender does not do it, there's a high demand for anyone who's willing to make professional/studio-grade tutorials from the first day a course series like that drops. I hopped onto the site looking for any Blender tutorials that cover that type of workflow today!
Out of curiosity, is there an ideal timeline for how long you'd be looking at doing and completing this series to launch? Q1-4 of 2025/2026? The Community's been aching for this essential workflow for quite some time.
second! i find myself continually returning to this post to see if there are any updates haha
@Lael Thanks and yes I agree with you that there's content missing for more advanced setups and professional work environments. Regarding the planning of the series, first we'll make our own character rig and release it, which is planned this summer. During fall, we'll evaluate and start recording a course for it. We're aiming to get it done by the end of the year, if all goes well :)
yes I definitely need that course!
This course looks very interesting, I will really enjoy it！
A vote of "yes, please!!" from me, I think this would be fantastic!!
oh yes please! I and im sure many others would absolutely love such a course! This is so cool!
yes this would be the best next course possible
Wow amazing proposal. I would love a course like that, especially with examples of what kind of expressions it needs to be created/sculpted.
Yes. I plan on using Blender almost exclusively on my productions. A better facial rigging and animation workflow would be welcome. Such tools would prove invaluable.
I definitely need that course!
I’m currently working on a facial rig for my personal work. I’m definitely interested, so please go ahead!
Yes, yes, yes and yes
Yes! I'd be very interested in a course on rigging with shape keys.
Yes to a course please!
This article was so interesting!!! I'd love to know more about this kind of facial rigging. So far I have used mainly bone based face rigs, but this kind of rig seems much closer to what ideally I'd like to create for the animators I work with. So the answer to the question is: YES!
It would be much helpful if blender supports non linear shape key, I love your proposal!
I would love a course like this! Thank you!
I accidentally sent the comment early but to add on to this: I'd love to see a solid workflow for Shapekey based facial rigs. I wish the shape key editor was a bit easier to use since good facial rigs use a ton of shape keys and it's hard to keep them organized without folders. And sadly performance for sculpting decreases a lot when having any shape key on the mesh, making sculped shape keys a bit harder to create for more high resolution meshes. And one thing I like about bone based rigs is that you can apply it to different, similarly looking rigs and then adjust it a little but with shape keys every key needs to be redone completely. I'm not sure if this is something that can improve or just a fundamental drawback of Shape keys but either way, I really love both approaches and would love to see both get more love, especially Shape Keys. Because right now the setup is quite long and not straightforward, needs scripts and addons like Pose Keys to feel a bit more streamlined and there aren't many resources online that really go indepth. So I really appreciate the proposal and am super excited!
This is fantastic! I feel like facial rigging is a Blender topic that's not wildly discussed or improved upon yet. I'd love to see a course on it. I've avoided shape key based facial rigs because of the massive time it takes to set them up and because they easily break if things like topology change mildly while bone rigs are more flexible but more tedious to get right. I used a bone rig with corrective shape keys and action constraints using Cloud Rig recently and it worked quite well though the workflow also isn't super clean
This is very incredible! I think it's extremely important to have a course like this here in the community, explaining this process step by step!
This only prepares blender users even more for the industry, and we are increasingly breaking the paradigm that only software X or Y can achieve good facial rigging results, no! Blender is here and it is also very capable!
I would love to see better shape key driven tooling! I know not directly related but I'd love to see a way to project shapekeys onto a different model with different topology. So if you make your shapekey set you can speed up pipeline work a little.
I will 100% be on the look out for your course!
Some sticky stuff also needs to be implemented, if you know what I mean) sounds like it will be a great, industry approved course, thanks!
This is a fantastic proposal! As an animator, I completely agree that shape key-based facial rigs provide the most control over designed deformations.
I really appreciate the breakdown of your process. I would also love to see the entire workflow in Blender benefit from better tooling and quality-of-life features. Optimizing the way shape keys are stored, improving iteration workflows, and introducing dynamic operators would make a huge difference in making this method more accessible and efficient.
Looking forward to seeing where this goes! And I'd definitely love a whole course for this. I’ll happily sign this "petition"! 😄
Hiya Rik. This course would be a fantastic asset to the community. I love that you're thinking about ways to semi-automate some parts so the artist can focus their energy where it really matters. Count me in!
Super interesting! I would love to see such a course:)
Love the attention for this topic, and I have many thoughts.
- Even though it's possible with geo nodes, supporting local/global rigging can help with more performaned rigs and easier blendshape management
@Jorn Boven I fully agree, though there will be some geonodes setup involved to automate some parts of the pipeline, but keep it as artist oriented as possible :)
- There are some really interesting curve based blendshape splitting tools that could be interesting for blender to look at! Also is a huge help for this workflow.
- The current way display override transform works has some issues with the pivot, making scaling and rotate weird to use. Perhaps custom depsgraph could fix that issue (including the performance hit those vertex parents take)
- A lot of these blendshape rigs make use of pose readers. Adding that natively would be a huge blessing too!
@Jorn Boven Yes! Some sort of RBF pose reader like the one Ingo Clemens from Braverabbit made for Maya would be amazing.
It would be awesome to have it! Setting up body rigs with riggify and/or cloudrig is quite straightforward but I'd love to learn a more straightforward approach to facial rigging
I would love to see such course one day!
Yes! Please make a course or workshop on facial rigging!
@Parker Wouters That's the plan!
Hi, thank you so much for this, It would be amazing to have a course about this process.
@frederic multier yes!
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