That is one full bag of gold nuggets Brad - thanks for the insight and
thorough walkthrough!

best
Morten Bartholdy



Den 21. juni 2012 kl. 17:53 skrev Bradley Gabe <witha...@gmail.com>:

> 3-phase process, with the generic, resizeable rig evolved and tuned to
> perform for phase-1.
> 
> Phase-1 is getting your joints placed, defining your volume, and sorting
> out coordinate space and rotation orders:
>     * Joint Placement :
>           o I use a technique where I create a temporary deformer where the
>             static kinematic state is linked to the parent. This way, you
>             can rotate the deformer, then shift the parent around and find
>             where the sweet spot of deformation is with real time feedback.
>           o Have tools that help you with this process, but at a more
>             atomic level.
>           o I used to have scripts that would generate hand rigs from
>             curves, but there was so much variability with fingers from one
>             character to the next, and then variability with animator
>             control preference, it wasn't saving me any time. I was
>             spending more time with weight painting fingers and interactive
>             joint placement anyway.
>           o At this point, I have tools that allow me to generate chains
>             from curves, but more importantly tools that generate guide
>             curves from existing chains. The tools are focused on allowing
>             maximum rigging flexibility, but more importantly on speeding
>             up the bottlenecks during deformation tuning.
>     * Defining Volume :
>           o Assume you are going to be using GATOR to transfer your
>             envelope onto other meshes.
>           o If you are lucky enough to have friendly modelers, they might
>             do you the favor of always delivering a full, low res, unibody
>             cage.
>           o Often, you'll instead get a character mesh that's made of
>             pieces of garments, a section of undershirt, the lower segment
>             of the arms, a neck that ends under the collar, etc.
>           o If you want to have any hope of using the envelope painting and
>             smoothing functionality while keeping all the disconnected
>             garments from crashing with the body parts you'll need to
>             create a volume mesh for weight painting and transferring.
>           o If you are having trouble getting areas of your character to
>             deform properly, try drawing profile curves and experimenting
>             with them. It takes far less time to mess around with the
>             weighting of a few vertex points, and if you can't get a
>             simple, 2D profile curve to deform the way you want with your
>             current rig setup, there's no way you'll get a much higher res,
>             3D mesh to do it.
>     * Sorting out coordinate space and rotation order:
>           o Extremely important, but often overlooked, even by more
>             experienced riggers.
>           o Too many people think that the zero space for animation is
>             defined by the envelope rest pose, but there is no reason at
>             all for this.
>           o Rather, all animation controls should be set based on the most
>             ideal rotational space to avoid gimbal lock in typical
>             performance situations. (Example: Use ZXY for the central body
>             controls. With XYZ, you hit gimbal lock the moment your
>             character turns 90 degrees in world space, which happens all
>             the time!)
>           o Rotation order should be thought about for each animation
>             control, but it also should not be set in stone. Different
>             scenes might call for different settings, and your pipeline
>             should allow for this.
>           o Make sure your numerical values for animation controls and
>             fcurves make intuitive sense and have some kind of obvious
>             alignment with world space, because you never know what
>             production is going to throw at you. (Example: I've seen rigs
>             where the feet are angled apart in the rest pose, and zeroing
>             out the feet animation controls returns to the angled pose. The
>             problem is, when moving the feet forward in their local space,
>             they spread further and further apart. This was making it
>             really tough on animators who were trying to work out walk and
>             run cycles, since the characters would end up doing the splits
>             the further they cycled through world space.)
>           o Because of this, my Envelope Binding Pose is never the same as
>             my Animation Rest Pose
>                 + Envelope Binding Pose - The rest pose of the mesh as
>                   delivered. This Pose establishes the foundation for your
>                   volume deformations (If it's a T-Pose, you might need to
>                   have a serious chat with your modelers).
>                 + Animation Rest Pose - Where all your animation controls
>                   go when you zero out the rotations and positions. A well
>                   thought out Animation Rest Pose will almost always make
>                   for a lousy Envelope Binding Pose.
>           o Use the Mixer to store your Binding Pose and your Animation
>             Rest Pose, and keep them with every instance of your Model.
>           o It's in this area I see most auto rigging setups fail. They
>             provide guide tools that allow the rigger to match exactly to
>             the Envelope Bind Pose, but they don't allow access to control
>             over the Animation Rest Pose.
> Getting through Phase-1, with practice, should rarely take more than a
> production day, and in many cases, only a couple of hours. For some simple
> 1-off characters, you might not even need more phases.
> 
> The main purpose for phase-1 is to hand off the rig as quickly as possible
> to your animators so they can start trying to break it and block it into
> scenes. At this point, you should also start getting feedback and be
> prepared to make repairs and adjustments. You will also want to use their
> performances and advice for feeding into phase-2.
> 
> Phase-2 Adding secondary deformation effects
>     * corrective shapes
>     * face shapes
>     * flesh jiggle
>     * skin sim
>     * muscle
>     * etc
> This is, in my opinion, the more creative area of the rigging process, and
> where it's been so interesting to have the power of ICE these past few
> years. The Non-Linear nature of XSI makes it possible to allow your
> animators to work with the phase-1 rig while you continue on to phase-2.
> 
> Phase-2 rigging is also the reason a rigger need not fear the existence of
> auto-rigging setups, since, (as Eric T. suggested) their main purpose is to
> get through phase-1 as quickly as possible.
> 
> Phase-3 Complex secondary rigs. Hybridized components that ride on top of
> the character mesh and require direct animation control, often combined
> with simulation.
>     * Simulated cloth and hair
>     * Character animated accessories (bags, straps, chains, jewelry)
>     * Character animated cloth and hair components (whiskers, brows, facial
>       hair)
>     * High level of difficulty - Animating interaction with straps, ropes,
>       chains, that have fixed length but also require sim.
>     * They often require constraining nulls to polygon clusters, which are
>       then used as roots for additional rig setups. If their animation
>       controls are visible, it forces full evaluation of the underlying
>       rig.
>     * Thus, they tend to result in slower performance because they rely on
>       the finished evaluation of the phase-1 and phase-2 deformations.
>           o Example: a character wears a satchel on a shoulder strap.
>             Portions of the strap must be bound to the shoulder and chest
>             geometry of the character, which themselves are being deformed.
>             If you are running phase-2 shapes and jiggle sims on the body,
>             then the satchel strap deformation must also ride on these
>             results.
>     * They introduce annoying complexity into a pipeline, since they might
>       force multiple layers of caching, which create a stack of
>       dependencies to deal with for every revision.
>     * They happen towards the end of your rigging schedule, when you might
>       already be tired from finishing phase-1 and phase-2
>     * Your producer probably did not consider their impact on setup times
>       and shot production.
>     * Your animators are wondering how a rig that was performing nicely in
>       real time (during phase-1) is now chugging along (at phase-3) when
>       all they want to do is animate the whiskers
>     * Have an arsenal of custom, atomic-level tools available for quickly
>       handling phase-3 setups:
>           o Naming tools that deal with sequences and series of controls so
>             that you can use the resulting naming conventions to feed into
>             other tools and workflows.
>           o Creating and constraining nulls to selected components
>           o Creating control curves and meshes from selected components
>           o Setting constraints by proximity to curves and meshes
>           o Tools that allow you to transform scene objects using
>             deformations:
>                 + Transform from envelope
>                 + Transform from lattice
>                 + etc...
>           o Tools that build control setups for straps, chains, ropes
> 
> I have a nice arsenal of atomic level tools now for dealing with phase-1
> and phase-3, developed from almost 20 years of rigging experience. I might
> need to start thinking about packaging and selling them soon if there is
> enough interest in the community.
> 
> -Bradley =?56c9915e-a97e-47c4-bf1a-490d8e2e46a6--
> 

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