Advanced SMR II : Rig architecture


For years we have refrained from giving turnaround rigging prescriptions, because there are many IFs, and we thought that such advice has the potential to be misinterpreted.

We were hoping that all the comprehensive tool descriptions, plus the availability of a full turnaround sample file would provide all the necessary reference material for users to take the next step by themselves. Unfortunately, it seems, that this hasn't happened.

The reasons, we think, are mostly rooted in the common lack of solid understanding of nesting.
Many times we have seen Animate users (not necessarily with EDAP Tools installed) to put all facial features on the character timeline. Such practice is a very good indicator of experience and comprehension levels.

So, it turns out, part of our mission as tools developers, who want to improve the lives of animators and the quality of animation, is to try to reach those lost souls and somehow convince them that 'Nesting is the way to go!', and Element Welder is not meant to weld noses onto facial ovals.
Only after that, such users will be able to move further and start contemplating the engineering challenges of turnarounds.

This is Part 2 of our series on advanced Smart Magnet Rigging. If you haven't read Part 1, it may be good to start the journey there.

SMR architecture for multi-angle rigs

When it comes to multi-angle rigging there are generally two possible approaches to organizing assets (or a combination of the two), and the choice is often dictated by personal preference or better suitability for a particular animation style.
Each of these approaches might have pros and cons, while at the same time both provide good flexibility.

The purpose of the rig

It is very important to not forget that the rig is only a starting point. 

Various new states of the body parts have to be added to convey the best possible poses, in accordance with the established principles of animation; the goal should always be to maintain the stylistic consistency of the character and the project.

The rig should not determine what the character can do. This limitation should come from the internal logic of the design and the rig should be extended and amended as we animate, to allow full expression.

The rig does not have some special intrinsic value. The meaning of its existence is to make the process of animation faster and easier.

Organizing assets

Just like in part 1 of this article we described the technical methods to control and maintain metadata, let's now outline the various approaches to organizing assets.

Container of static variants
This is usually illustrated with the example of a mouth symbol or a hand symbol, and is the most easily understood one.
All hand gestures can be put inside one Graphic Symbol, each hand image occupying one frame. Then on the outside, the instance is stopped (Single Frame) and by choosing a different First Frame number we display the desired hand gesture at character level.

Container of unsynced animations
A container can hold not only static images, but also short animations, where one position transitions into another.
In this case, portions of its timeline will be played out of sync, using the Play Once option and defining the desired range with keyframes and First Frame.

Container of synced animation
A synced container is a Graphic Symbol set to Play Once. It plays in sync with both the character and the Main timelines.
The most common example here is the head, but it can be any body part. If a stroke or a custom brush is used for a limb, it is possible that in some shots, these legs and arms symbols will be played in full sync, while internally they will be Shape Tweened.

Swapping synced containers
A good way to illustrate this approach is the typical head, which has to play in sync from 1 till the end of the shot. In this case we have several head angles, each a separate Graphic Symbol, and swap between them. Frame numbers of internal and external timelines always match to maintain sync with the dialog and acting performance.

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Swapping static containers
For larger projects, which have a true pre-production stage, swapping can be effectively combined with containers of static variants as well.
For example, there can be multiple full turnarounds of a foot, which show it form above and from below. These can be organized each one in its own container of static images. If the symbols are put in a 'foot' Library folder and named in a way which alphanumerically orders them the way we want, we can scrub through the content of the current one with Next / Previous Frame in Symbol, and go up and down the grid with Previous or Next Symbol In Library to swap.

Video – Multi-symbol Arrays

Objectives for functional multi-angle rigging

The goal of functional multi-angle rigging is to organize assets in such a way, so that they can be accessed with the smallest number of clicks or key presses. They should also provide room to easily add more variations as needed, without slowing down the animation process, and at the same time keeping all these new assets as easily accessible as the original ones.

In the context of SMR, best practice is to have only one universal rig per character, where all body parts of one of the views are interchangeable with the corresponding body parts of the other views.
This means that metadata has to be synchronized internally and externally. 

The Symbol Instances representing the same body part across all views of the turnaround must have the same instance ID, i.e. if the left upper arm in the front view has an ID of 7, the left upper arm in 3/4 view must also have an ID of 7.
This synchronization is achieved very easily by Rolling Over Rig Info (RORI) from one rigged view to another.

Magnet Targets in these matching rig elements must also carry the necessary metadata.
If we look again at the arm example, its elbow MT will need to be copy/pasted from the front view symbol into the 3/4, profile and back view symbols, if such symbols exist.

Necessary decisions

Due to the different nature of the various body parts, they usually need to be organized and nested in different ways. In the Organizing assets section above we outlined the available options.

Some of the choices that have to be made are very obvious. If we will animate to dialog, the head has to run as a synced Symbol Instance, therefore we will need multiple symbols for the various angles. Putting them in a Library folder will allow for quick and predictable swapping.

Hands and feet
In most cases the hand or foot symbols will be set to Single Frame and frames will be chosen from a range of static variants. Sometimes there may be short animations in there as well, which will be Played Once as needed.

If we work on a larger production, an array of hands (and feet) may be organized where there are multiple symbols with full turnarounds, such as pointing, fists and so on. As explained earlier, these can be swapped, and then individual frames chosen from the current container.

The torso can be approached in two ways:

1. We can have only one torso container which has the turnaround views as frames inside, and we can also have some extra views and short animations in there. These short animations can be transitions between the main angles, or some stretching and squashing, bending and so on.
Magnet Targets will need to be adjusted to match the artwork.

2. We can separate the views, putting them each in their own container and swap them. This allows for cleaner access to short torso animations such as bending, twisting, shoulder shrugging, etc.

The choice between 1 and 2 is determined by the character design and anticipated range of movements.

Often times for specific parts of the animation, it may be practical to duplicate the torso symbol and work with this duplicate. An example would be an animal running. The torso in this case will have a very specific, looping squash and stretch, and it is best to keep that separate and synced with the run/walk cycle.

Arms and legs
Arms and legs will most certainly need foreshortened variations. How to nest them will be determined by the design.

Video – Foreshortening

Master container

One last thing that we need to mention is that we need to have a master container – a symbol which contains all other symbols.
It doesn't matter how they are arranged and displayed there.
The purpose of this is to be able to copy/paste or drop all the elements of our rig into the documents where we will animate them, so that the ones which are not initially on any timeline are available for us in the Library when we need them for swapping.

This is also the symbol (Library Item) which will contain the character's color palette metadata for Symbol Palette Control, if we need to have multiple palettes.


Now when all objectives are set and all methods are well understood, we can look at a practical demonstration.

Here the head is nested one level deeper to allow even faster blocking out of animation. After the initial pass the wrapper is broken apart and this exposes the different head containers, which will run in sync and will have the facial animation inside. This concept is known as Break Apart Workflow.

Video playlist – Advanced SMR techniques

Beyond rigging

A good, well-structured rig can make the work of the animator easier and more enjoyable. This can indirectly lead to better animation.

Even though in this article we have tried to describe the process in its entirety, and define the various challenges associated with rigging, this is neither a complete study, nor it is supposed to be followed step by step. Rigging is a creative process and all suggestions here are only rough guidelines, showing how you can combine the existing options and methods.
Real decisions will be made on a character-by-character basis and will be determined by the project's design style.

We have mentioned this elsewhere, but it is worth repeating: 

When you start animating, get into the habit of creating keyframes across all layers of your character and think of these as poses. Never only move a limb in isolation. This will make your animation look much more organic.

Use SMR to help you, but not lead you. Never forget that this is not a rigid rig, where the elements are nailed to their parents. You can move them away from the MT and everything will still work. Only when you need them to snap back, they will.

A good rig is a necessary prerequisite to making high-quality cutout animation, but does not guarantee it.
The time spent on rigging will only be justified if the animation produced with the rig is worth it.

The biggest challenges in cutout animation are stiffness of poses, floaty timing and a sense of disjointedness of the figures. All these can be overcome easily, when the animator learns to always think of the collection of body parts as one organic whole. Experience with hand-drawn frame-by-frame animation can help immensely in this regard, but is, unfortunately, getting more rare and more difficult to obtain in a professional setting. Young people have to invest huge amounts of time on their own to practice traditional animation and life drawing, which will then fuel their growth and abilities to produce better cutout animation faster.

Nickolay Tilcheff
April 2022


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