Ragdolls that physically play animations through the use of joints and rigid bodies. Made with Unity v2020.1.9f1.
You just need to clone or download this repository and open the project with Unity. It's made in Unity v2020.1.9f1, but other versions will surely work fine, especially newer ones.
Active ragdolls are quite messy to make. To avoid as much pain as possible and keep everything under control, I made a simple architecture that makes it all more maintainable and understandable.
An Active Ragdoll is a ragdoll that can apply forces to move itself. In this case the Active Ragdoll tries to replicate animations through the use of joints that target the rotations of an animation. The structure of an Active Ragdoll is the following:
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A parent GameObject that encapsulates two bodies, one plays standard animations and the other one is the ragdoll that tries to follow it with physics. This parent object contains the main ActiveRagdoll script, the basic code block to which Modules can be attached. Those modules contain independent functionalities which allow the character to perform different actions. A behavior script is also attached to this GameObject (this is all better explained in the next section).
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An animated body. This is just a standard animated character, whose animation will be physically copied by the ragdoll. The actual model is disabled because we do not want to see it, we want to see only the ragdoll. But disabling it stops animations from being played, so the animation mode of the Animator component must be changed to 'Always animate'.
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A physical body. This is a duplicate of the animated body, but with some major variations. First of all, the animator is still there, so certain functionality can still be used (such as getting the transforms of certain body parts), but it doesn't play any animation. The objects that comprise the body (left forearm, right thigh, neck...) are each given a RigidBody and connected among themselves by ConfigurableJoints, becoming what's essentially a ragdoll. All the ConfigurableJoints are then set up to apply torque to reach a certain rotation (these are called Angular Drives and Target Rotation). This rotation is set to be that of its equivalent body part from the animated body previously described. For example, the left forearm joint target rotation will be set to the animated forearm rotation. This way every joint will target its animated peer rotation, replicating the original animation with physical movement.
In terms of code, the behavior of the Active Ragdoll is divided into modules. This allows different functionalities to be completely independent to one another, and makes the code much easier to maintain. The code architecture can be described as follows:
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A script 'ActiveRagdoll' that acts as the main pillar of the rest of the code. It contains very basic functionality, the least possible that allows the rest of the modules to work together.
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Modules are just scripts that contain a specific functionality. They are completely independent from each other, and can be easily attached and detached. It's important to remember that they do not do anything by themselves, they provide function, not behavior. For that we need the following script.
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A behavior script attached to the parent GameObject. It tells the ActiveRagdoll what to do: what input to take, what actions should be taken in what situations, how to react to a specific environment change... To understand it better: ActiveRagdoll and its modules act like an API, this script is used to control that API.
- Unity (v2020.1.9f1)
Please read CONTRIBUTING.md for details on our code of conduct, and the process for submitting pull requests to us.
See also the list of contributors who participated in this project.
This project is licensed under the Apache 2.0 License - see the LICENSE file for details.
- MetallCore999 for inspiration.
- Michael Stevenson for its Configurable Joint Extensions script.