The "When and How" of Joints
Toon Boom Digital Pro offers a lot of tools and possibilities, especially when it comes to character breakdown and rigging.
There are three main techniques used to create an articulation:
- Classical Joint
- Patch Joint
- Glue Joint
Here are some tips and tricks on when and how to use these joints.
The classical joint is a very common technique. It’s easy to create and use, but not necessarily the most efficient.
This technique consists of simply removing a part of the line on the overlapping part. For the classical joint to work
well, the joint has to be done out of a perfect circle and the pivot has to be placed right in the center, otherwise it
may not work properly all the time.
If the character design has a square elbow and articulation style, the classical joint won’t work.
The classical joint may be easy to create, but will cause trouble later on during the animation. So, we recommend using
another technique called the Patch Joint.
When to use the Classical Joint
Only use the classical joint when you create a very simple and basic cut-out character. In production or for a series,
always use the patch joint. The joint is easier to handle.
The patch joint is a useful technique. Created at the breakdown and rigging step, the patch creates a clean articulation
allowing a lot of freedom for the animator.
This technique consists of creating a little colour patch matching one of the parts in the articulation. Then the second
part is sandwiched between the patch and the other part. For example, the forearm will be placed between the arm and a
patch matching the arm shape. The patch will be linked to the same motion as the arm so whenever the arm moves, the patch
follows. The animator does not even need to bother about the patch. It is like it does not exist. The forearm can even be
repositioned, deformed, the animator can move the pivot point and the joint will still work.
When to use the Patch Joint
Use the patch joint whenever you can. In production, series and feature films it is easy to animate and gives a professional
result.
The most common articulations done with the patch joint are the elbows, knees ankles, wrists and shoulders.
The patch joint can also be used when a character’s hat or hair has to pass in front and behind the head. Then the head
layer will be placed between the front and the back hat.
The glue joint is an advanced technique. The glue joint is created out of an effect module placed in the network rigging.
The glue module must be considered as a tool to assist the animator. As the effect is computer generated, the animator
does not always have full control of the joint result during the animation.
This technique consists of making a matching straight cut on the two parts involved in the articulation. The glue will
calculate the missing gap for the cut. It is very important that the two drawings match perfectly to avoid holes or
glitches in the joint result. Then, in the network, the two drawing modules are connected in a Glue module. When the
animator moves the articulation or pulls on the parts, the system will automatically create the missing artwork.
The glue joint allows you to create effects such as elastic body parts, sharp and square elbows or snake like characters.
Although, it is important to remember that the glue is an effect and is computer generated, so if a character has a lot of
glued articulations, it will be heavier to calculate and animate.
Note that the Glue module will often give better results with Pencil lines. However, the drawing cut has to match
perfectly.
When to use the Glue Joint
Use the glue joint only when necessary. If the character has a special design such as a patch on the elbow (vector
drawings only), you can use the glue module. You can also use the glue module if you want to create an elastic character.
For the rest, use the patch joint.
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The Classical Joint
