2023-04-11 Animation & Rigging off-schedule module meeting

The meeting will be on 2023-04-11T10:00:00Z. It is open for everybody interested to join on Google Meet (link below).

Present: Armin Halac, Ivan Cappiello, Marion Stalke, MohammadHossein Jamshidi, Nathan Vegdahl, Orestis Konstantinidis Sybren Stüvel

People present are referred to by first name for brevity. Others are referred to by full name.


Short-term goals / Ongoing Work

Autoriggers & Rigify

Discussion between Armin, Nathan (as 2nd original author of Rigify), and Ivan, about how to adjust Rigify (or make a new ‘auto-rigging’ tool) to be more game engine friendly.
- One issue Ivan mentions are bendy bones, and them being so specific to Blender. Also they’re lacking widgets to directly influence the bending of the bones. In the past he has exported the bendy bone influence to a shader and handle that in the game engine.

UnrealEngine Control Rig

UnrealEngine Control Rig (CR) is a big source of inspiration (tutorial).

  • Joseph Brandenburg’s rigging nodes add-on is mentioned. Nathan: this is super cool & orthogonal to what CR can do.
  • Orestis: reminds of Ephemeral Rigging. Good for posing, how does it interpolate?
  • Nathan: definitely challenge to solve
  • Sybren: CR can do a ‘backward solve’, but AFAIK not all the math is guaranteed to be invertable. Having ‘shadow bookkeeping’ of the original control parameters, used as a starting point for the backward solve, might help to stabilize this.
  • Ivan: Rigify is mostly for animators, not for riggers. Animators can use it to create their own controls. Is CR too scary for animators to use themselves? How Mixamo approaches this might be interesting to look at too, as they have different interfaces for animators and riggers, sharing the same underlying system.
  • Armin: CR can work like that as well, where it can generate more classical rigs. The strength is that you can do much more without creating any dependency cycles. No snapping between IK and FK chains, for example, so it ‘just works’ from the animator’s PoV.
  • Sybren: we’ll have to make some examples at different levels (from simple to complex) to illustrate and understand where we want to go. Having something that’s as easy as Rigify’s ‘add human metarig / adjust / generate’ is important.
  • Sybren: The goal of our project, as Ton describes it, is to get animators 10x as fast (in terms of seconds-per-week output). Animators having to re-do animations because of a rig update is a big source of slowdowns, currently.
  • MohammadHossein: good rigging also helps in procedural animations.
  • Sybren: my hope is that it’ll also make it easier to combine animation from varying sources (like mocap + physics sims + manual animation)
  • Nathan: The separation of ‘control’ from ‘articulation’ also allows for shot-specific control rigs. The hard part is to be able to say ‘until frame N, use that rig, and from frame N+1 use another one’.
  • Orestis: Ephemeral Rigging is fantastic for top-tier animators, speeds you up when you know exactly what you want to acomplish. For other experience levels, or just other purposes of animation, other appraoches could be better/friendlier/faster.
  • Sybren: CR visual debug is cool, it allows you to see the transform outputs of nodes. And we could use something similar to show hidden matrices (like ‘parent inverse’).
  • Marion: better visualisation of transform orientations (local, global, parent, etc.) of constraints / props / helper objects would also help a lot.
  • Ivan stresses the importance of really nailing a simple approach for a prop hand-over between characters, because currently it is both ubiqitous and still cumbersome.
  • Marion: concrete suggestion for solution: could be a concrete bone setting that it should also be visible & usable ‘outside’ of the rig. That way another rig can use it to create a constraint between its ‘outside bone’ and that ‘outside bone’.
  • Orestis: next steps?
  • Sybren: try animating in UE, get animatino from Blender and adjust in UE with CR.
  • Orestis likes.
  • Marion: wonders about handling of scaling bones.
  • Orestis: Blender’s Outliner needs some work, especially when objects are used as controllers it might make its weaknesss more annoying.
  • Sybren: maybe a new mode for the outliner for animators, with controls. MHJ: no more modes, please! Sybren: could be integrated with the workspaces system, so that a workspace is just ‘set up for animators’.
  • Module: Pose mode is great! Has some downsides, but overall very desirable. Marion: helps riggers & animators too, as animators have a much harder time breaking a rig than in other softwares.
  • MHJ thinks rigging has to be done in edit mode not in pose mode so animators cannot touch it. Orestis: Yeah very good point. The animator is more like a user. Sybren also wants to be able to add constraints & set up bone groups in edit mode.
  • Armin: free Control Rig course: Bring your character to life! Rigging - FlippedNormals

Next Meeting

The next meeting will be on Thursday 2023-04-20T16:00:00Z. Again it will be open for everybody who’s interested. The provisionary meeting agenda will be linked in the #animation-module channel before the meeting.