2021.1.1124.2 Helical Joint

1 Overview
2 Where to find
3 Feature layout
4 How to use

Overview

Constraints the motion of a GameObject to translation over a Spline and rotation by Pitch and position along the Spline.

Where to find

The Helical Joint can be found under Mechanics > Kinematics > Kinematic Joints > Helical Joint.

This will add the Helical Joint component to the currently selected object or create a new empty GameObject with the component attached if no objects are selected.

Joints must be placed as children of a Kinematic Controller in the hierarchy

The following inspector component will be shown:

Feature layout

The image below shows the complete feature layout of the Helical Joint component.

Generic Joint Settings
Pass Priority	Priority of the kinematic chain calculations. Higher numbers are calculated earlier.
Enforce Outside Playmode	Enforces the joint to work in edit mode.
Prevent Kinematic Update	Removes the joint from the kinematic chain calculations.
Prevent Further Kinematic Update on this GameObject	Allows lower priority kinematic transforms on the same GameObject to be skipped in calculations.
Allow Direct User Input	Allows the user to manipulate the joint with the scene gizmo.
Min. User Input Translation Offset	The minimum value the user must input before translations are applied.
Min. User Input Rotation Offset	The minimum value the user must input before rotations are applied.
Kinematic Chaining
Create new Leading Transform Relation	Creates a new relation between Transforms.
Opposing Relation Instance	The kinematic transform you want to link the joint to.
Relation Direction	Describes the direction of the manipulation of the Transforms. The following options are available: BIDIRECTIONAL: Allows for both kinematic transforms, when they are being manipulated, to manipulate each other equally. RECIEVE_ONLY: Allows for the joint, when it is being manipulated, to manipulate the opposing kinematic transform, but not the other way around. SEND_ONLY: Allows for the opposing kinematic transform, when it is being manipulated, to manipulate the joint, but not the other way around.
Relation Type	Used when 2 different size Wheel Joints need the same rotational speed. The following options are available: TRANSLATION: Translates the transforms using the Wheel Radius. ROTATION: Translates the transforms without using the Wheel Radius.
Motion Direction is Reversed	When enabled, the manipulation to/from the opposing kinematic transform is inverted.
Helical Joint Settings
Pitch	The distance from the crest of one thread to the next.
Invert	When checked inverts the direction of the rotation.
Limit Relation & Update Settings
Spline	The Spline along which the Helical Joint’s position and rotation is constrained.

How to use

Create a Spline and use it to define the path you want the Helical Joint to follow.
Add the Spline to the Helical Joint and create a new Transform Relation, add an Opposing Relation Instance and define the other settings as needed.

Test if the

Transform Relations are working.

To test your Transform Relations outside of playmode make sure Enforce Outside Playmode is checked on both Joints.