2023.1.1571.2 Double Prismatic Joint

1 Overview
2 Where to find
3 Feature layout
4 How to use
5 How to use Limits
6 How to use Soft Limits

Overview

Constrains the motion of a GameObject to a translation over a DSpline.

Where to find

The D Prismatic Joint can be found under Mechanics > Kinematics > Kinematic Joints > Prismatic Joint and will be added to the selected object. Without a selection, a D Prismatic Joint will be added to a new empty GameObject.

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

The inspector for a newly added Prismatic Joint will look like this:

Feature layout

The image below shows the complete feature layout of the D Prismatic Joint inspector.

Generic Joint Settings
Pass Priority	Priority of the kinematic chain calculations. Higher numbers are calculated earlier.
Enforce Outside Playmode	Enforces the prismatic joint in edit mode.
Prevent Kinematic Update	Removes the prismatic joint from the kinematic chain calculations.
Min Translation Delta	The minimum value the joint detects as a change in position.
Min Rotation Delta	The minimum value the joint detects as a change in rotation.
Kinematic Chaining
Show in Scene View	Shows chained connections of this object through arrows.
Show When Not Selected	Shows chained connections of this object through arrows even when the object is not selected.
Add Kinematic Transfer Relation	Select a Kinematic Body to transfer over the Spline. Alternatively, drag a Kinematic Body into the field.
Opposing Kinematic Relation	The Kinematic Body to which this relation is connected.
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.
Ratio	The ratio to which the relation is applied (1 means all the applied rotation translation is equally transferred).
Invert Relation	Check to invert the direction of the relation. (Rotating right will result in a left rotation).
Prismatic Joint Settings
Apply Rotation Spline	Check to apply the rotation of the Spline to the joint.
Apply Soft Limit	Check to apply a soft limit (percentage-defined).
Lower Limit	The soft lower percentage limit.
Upper Limit	The soft upper percentage limit.
Constraining DSpline	The DSpline used to constrain this joint.
Spline Length	The length of the spline
Current Spline Position	Normalized position of the Prismatic joint over the spline between 0 and 1.
Target Control Point	The Spline point to be used for Update Limit ControlPoint.
Update Limit Control Point	Updates the Target Control Point to the current spline position.

How to use

Create a DSpline and use it to define the path you want the prismatic joint to follow.
Add the DSpline to the Kinematic Prismatic 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.

How to use Limits

Position the Kinematic Prismatic Joint object along the spline.
Select the point in Target Control Point you wish to change and click Update Limit Control Point.

How to use Soft Limits

Position the Prismatic Joint object along the spline.
Click Apply Soft Limit
Set the Lower limit and Upper limit
The Prismatic Joint is now constrained by the new Soft Limits
Turning off the soft limits enables the joint to move all the way over the spline