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-- >
