hook

Constrains one or more nodes to one or more target nodes using matrix connections.

This modifier is a powerful alternative to standard transform constraints. By using matrix math to drive the transforms, it provides better evaluation performance, avoids Euler flipping, and allows for clean "virtual parenting" setups without cluttering the scene hierarchy.

Usage

The behavior of this modifier fundamentally changes based on the group parameter.

Direct Connection (group: off)

This is the default behavior. No new nodes are created in the scene hierarchy. The modifier directly drives the transform matrix of the specified nodes using the targets' matrices. This is perfect for seamless, invisible space-switching or blended constraints.

Hook Group (group: on)

The modifier creates a brand new physical transform node (the "hook group") in the hierarchy. This new node is matrix-constrained to the targets, and your driven nodes are physically re-parented under it. This is ideal when you need a clean pivot point or a dedicated group to attach a prop, a limb, or a sub-rig without altering the driven node's local coordinates.

Parameters

Driven (Destination)

Parameter	Type	Default	Description
node	node		Single node to be constrained or re-parented.
nodes	list[node]		Multiple nodes to be constrained or re-parented. (If both are provided, they are combined).

Drivers (Sources)

Parameter	Type	Default	Description
target	node		Main driver node.
targets	list[node]		Additional driver nodes. (Combined with target if both are set).

Behavior & Settings

Parameter	Type	Default	Description
group	bool	off	Determines the operation mode. If on, a physical hook group is created and the nodes are parented under it. If off, applies direct matrix connections.
parent	node	Parent of nodes[0]	(Only if group: on) The node under which the newly created hook group will be parented.
maintain_offset	bool	on	Maintains the relative spatial offset between the targets and the driven nodes at build time.
weight / weights	float / list		Constraint weights for each target. Defines the blending between multiple drivers. If explicitly provided, it forces the creation of weight attributes (see Output.
name	str	optional	Custom base name for the generated hook node and its ID. Highly recommended for cross-referencing (see Output).

Single Target Switch

By default, if you only have a single target, the connection is direct and absolute. However, explicitly defining a weight parameter will force the system to generate a weight attribute (@w0). This gives you a convenient on/off toggle for the constraint.

Output

Attributes: If multiple targets are used, or if the weight parameter is explicitly provided, the constraint weights are exposed as animatable attributes on the constrained node (e.g., @w0, @w1, etc.). This allows animators to blend targets or toggle constraints at runtime.

Generated IDs: If group: on, the new transform node is prefixed with hook_ and registered internally. This is where the name parameter becomes crucial. Naming your hook allows you to easily target it later in your build process:

• <id>::mod.hooks.<name>

Best Practice

Always provide a name when group: on. If omitted, Mikan will assign a numerical index or an auto-generated string based on the targets. These fallbacks are unpredictable and make it very difficult to reference your new hook group reliably in subsequent modifiers.

Reparenting Safe

Because this modifier relies on robust matrix math both the generated hook group and the constrained nodes can be freely reparented anywhere in your rig hierarchy after creation. No parasitic offsets or double-transformations will occur.

Examples

Direct Matrix Blend (No Group)

Constraining multiple nodes directly to two targets with a 50/50 blend. No hierarchy is changed, and no new groups are created.

hook:
  nodes:
    - my_prop::roots.0
    - my_other_prop::roots.0
  targets:
    - driver_A::node
    - driver_B::node
  weights: [ 0.5, 0.5 ]

Creating a Hook Group (Virtual Parent)

This setup creates a physical hook transform driven by the source_node. The node_id_1 is then reparented under this new hook. This is a classic setup for attaching the root of a template to another part of the rig.

hook:
  node: knee_pad::roots.0
  target: leg.L::skin.dn.2
  group: on
  weight: 1
  name: pad