SkeletonModification2DTwoBoneIK

Inherits: SkeletonModification2D < Resource < RefCounted < Object

A modification that rotates two bones using the law of cosigns to reach the target.

Description

This SkeletonModification2D uses an algorithm typically called TwoBoneIK. This algorithm works by leveraging the law of cosigns and the lengths of the bones to figure out what rotation the bones currently have, and what rotation they need to make a complete triangle, where the first bone, the second bone, and the target form the three vertices of the triangle. Because the algorithm works by making a triangle, it can only operate on two bones.

TwoBoneIK is great for arms, legs, and really any joints that can be represented by just two bones that bend to reach a target. This solver is more lightweight than SkeletonModification2DFABRIK, but gives similar, natural looking results.

Property Descriptions

  • bool flip_bend_direction

Default

false

Setter

set_flip_bend_direction(value)

Getter

get_flip_bend_direction()

If true, the bones in the modification will blend outward as opposed to inwards when contracting. If false, the bones will bend inwards when contracting.


  • float target_maximum_distance

Default

0.0

Setter

set_target_maximum_distance(value)

Getter

get_target_maximum_distance()

The maximum distance the target can be at. If the target is farther than this distance, the modification will solve as if it's at this maximum distance. When set to 0, the modification will solve without distance constraints.


  • float target_minimum_distance

Default

0.0

Setter

set_target_minimum_distance(value)

Getter

get_target_minimum_distance()

The minimum distance the target can be at. If the target is closer than this distance, the modification will solve as if it's at this minimum distance. When set to 0, the modification will solve without distance constraints.


Default

NodePath("")

Setter

set_target_node(value)

Getter

get_target_node()

The NodePath to the node that is the target for the TwoBoneIK modification. This node is what the modification will use when bending the Bone2D nodes.

Method Descriptions

  • NodePath get_joint_one_bone2d_node ( ) const

Returns the Bone2D node that is being used as the first bone in the TwoBoneIK modification.


  • int get_joint_one_bone_idx ( ) const

Returns the index of the Bone2D node that is being used as the first bone in the TwoBoneIK modification.


  • NodePath get_joint_two_bone2d_node ( ) const

Returns the Bone2D node that is being used as the second bone in the TwoBoneIK modification.


  • int get_joint_two_bone_idx ( ) const

Returns the index of the Bone2D node that is being used as the second bone in the TwoBoneIK modification.


  • void set_joint_one_bone2d_node ( NodePath bone2d_node )

Sets the Bone2D node that is being used as the first bone in the TwoBoneIK modification.


  • void set_joint_one_bone_idx ( int bone_idx )

Sets the index of the Bone2D node that is being used as the first bone in the TwoBoneIK modification.


  • void set_joint_two_bone2d_node ( NodePath bone2d_node )

Sets the Bone2D node that is being used as the second bone in the TwoBoneIK modification.


  • void set_joint_two_bone_idx ( int bone_idx )

Sets the index of the Bone2D node that is being used as the second bone in the TwoBoneIK modification.