Creating a full body Foot Placement IKINEMA Rig

1 Pre-requisites before setting up the foot placement node

 

1.1 Generating the IKINEMA Rig

The first step to achieve the above behaviours is to create an IKINEMA Rig for your character. There are two ways to create an IKINEMA Rig asset.

 

(a) In the content browser in Unreal Engine, navigate to the skeleton asset of the character.

Right click on the skeleton asset and select IKINEMA Rig Actions -> Create IKINEMA Rig.

 

 

(b) In the content browser in Unreal Engine, right click in the background. 

Select Animation -> IKINEMA Rig in the context menu.

You will be prompted to chose the Skeleton asset you wish to create the IKINEMA Rig for.

 

The above two methods will create the IKINEMA Rig asset used by the IKINEMA nodes in the animation blueprint.

The IKINEMA Rig will be populated with the bones included in the targeted skeleton asset. The joints included in the IKINEMA Rig will be taken into consideration in the full body solve.


1.2 Setting up the IKINEMA Rig

To create a typical full body biped IKINEMA Rig for the foot placement node proceed as follows: 

1.2.1 Delete the unnecessary bones that do not need to be taken into consideration in the solve. 

Important: The root bone of the character should be excluded from the IKINEMA Rig. The first bone in the IKINEMA Rig should be the hips bone for example. If the root bone is included, manually delete it from the IKINEMA Rig. You can do this by selecting the bone and pressing the delete key.  

The typical bones unnecessary for the full body solve include finger/face/IK/Twist/Roll joints that are included in the characters skeletal asset.

The image below shows what the typical biped hierarchy in the IKINEMA Rig could look like once unnecessary bones have been removed.

1.2.2 Assign IK Tasks to key joints.  

Within the Rig editor you can assign pre-set tasks to key body parts. 

To do so, right click on a joint in the hierarchy and select ‘Constraint type’ you will see the presets available. 

To add a constraint, select the applicable task pre-set. 

These presets are also bound to certain keys shown in the image below.

When you select a joint and press the relevant key, the pre-set task will be added to the joint automatically. 

The task key binds are as follows:

H - Hip Task

T - Foot Task

D - Hand Task

Q - Head Task

C - Chest Task

K - Knee Task

1.2.3 For a typical biped add the following tasks: 

  • 2 Tasks per foot (this can be one task per foot) 
  • 2 Knee tasks 
  • 1 Hips task 
  • 1 Chest Task 
  • 1 Head Task  
  • 2 Hand Tasks 


If you have followed the above steps, the generated IKINEMA Rig can be used with the foot placement node to give your character full body foot placement, lookat and weapon wielding capabilities procedurally.