Functionality
Welds an element of a Smart Magnet Rig to its parent.
There are two modes of welding: Soft and Hard.
Soft welding: When a child element is soft-welded to its parent, it always moves in Hard Rotation when the parent is rotated with KineFlex. Soft welding is uni-directional – the child can be rotated independently of the parent.
Hard welding: When a child element is hard-welded, the child will follow the parent as in Soft welding, but also the parent will follow the child. Hard welding is bi-directional.
Welding and un-welding
To weld an element, select Symbol instance(s), which are part of a Smart Magnet Rig, on Stage and click on the Element Welder button 
in the SMR Helpers panel. Choose Hard or Soft welding in the dialog that pops up.
To un-weld a welded element, select it on the Stage and click on the Element Welder button in the SMR Helpers panel and choose Remove in the Element Welder dialog that pops up.
Snapping of welded elements
Smart Magnet Joint detects welded elements and can also adjust their rotation to match that of the parent.
If the welded element is in position over the Magnet Target, pressing the ` key will restore rotation in relation to the parent at the time of welding.
If the welded element is moved away from the Magnet Target, pressing ` will snap it into position. A second press of ` will restore rotation in relation to the parent at the time of welding.
Fix Flipped
In some specific use cases after flipping, welded elements' angle will not be restored according to user expectations, when triggering Smart Magnet Joint `. This only happens to welded elements which are not Duplicates or parts of the same object with matching Registration Points and transformations.
In these cases, after flipping, it is necessary to re-record the angle between the welded and its parent in the current keyframe.
This is done by simply selecting the elements on the stage, pressing the Element Welder button in the SMR Helpers panel and choosing Fix Flipped.
Automatic creation of hard-welded duplicates
Element Welder also offers a convenient way to create a hard-welded duplicate of the selected SMR element. This simplifies the process of rigging of overlapping elements with coinciding Registration Points.
To create Duplicates, select one or more elements of a Smart Magnet Rig on the Stage and press the Element Welder button in the SMR Helpers panel. Choose Duplicate. New layers will be created on top of the current ones, the instances will be duplicated, rigged as a child of the selected ones and hard welded.
Please note: Duplicates are end-of-chain elements and cannot have children of their own. Also, you cannot duplicate a Duplicate.
Duplicating non-SMR elements
Duplication is not strictly limited to SMR elements. Any symbol instance can be duplicated.
One practical application is in facial rigs, where Visibility Switches may be used. These Duplicates created by Element Welder can be realigned with the originals by Alt-Shift-clicking on the Visibility Switch with KineFlex.
Suggested use
All situations where Soft Rotation with KineFlex is undesirable.
Hard welding an element to its parent allows to have movable parts 'sandwiched' between front and back parts of the same object. For example, the back part of a sleeve or skirt, where the front part is the parent and the back is a welded child. Another example could be a turtle shell.
Also: Hard welding various elbow and knee patches in rigs with outlines.
A different usage scenario could be the large ears of a rabbit, soft-welded to the head. When the head is rotated with KineFlex, the ears always move in Hard Rotation, but as children can still be rotated individually.
Element Duplication is useful in situations where an element which is normally layered behind another one needs to temporarily appear in front. For example, the hand of a character in 3/4 view which typically stays behind the torso sometimes needs to reach in front of the torso or the head. A hard welded duplicate on a top layer elegantly solves this issue.
Where does it work?
Selected Symbol instance(s) on Stage (to weld or un-weld)
Notes
Element Welder only works with Smart Magnet Rigs
Welded elements can be seen, when a node representation of the rig is loaded in the Smart Magnet Rig panel
Video demonstrations
TransPoser workflow
