Drop-In Ragdoll

Drop-In Ragdoll gives any humanoid Godot character a ragdoll. Add one node under its Skeleton3D, call go_limp(), and the character falls. Call get_up() and it blends back into its animation.

What it does

• No setup per character. It finds the bones by name (Godot humanoid, Mixamo, Unreal/MPFB, Blender .L/.R, 3ds Max Biped, VRoid). A BoneMap or a few bone names cover anything else.
• Sized to your character. Each body part's collision shape is fitted to the mesh around its bone, so a cartoon knight with a huge head gets a huge head.
• Any scale. A character scaled ×0.5 or ×1.4, or one inside a scaled scene, falls exactly like one at ×1.0. Godot's PhysicalBone3D shrinks its bones under a scaled rig; this doesn't.
• Bends the right way. Elbows and knees only bend one way, and every limit is measured from the rest pose.
• Settles cleanly. No twitching on the floor: bodies come to rest in a few seconds and go to sleep.
• Keeps momentum. On a CharacterBody3D or RigidBody3D, a running character tumbles forward.

Quick start

@export var ragdoll: DropInRagdoll  # a child of the character's Skeleton3D

func knock_out(attacker_position: Vector3) -> void:
    ragdoll.go_limp(attacker_position.direction_to(global_position) * 4.0)

func _on_ragdoll_came_to_rest() -> void:
    ragdoll.get_up()

In the download

• addons/dropin_ragdoll/: the addon. Copy it into your project; there's no plugin to enable.
• A demo project: four knights at ×0.6, ×1.0 and ×1.4. Click to hit them, Space knocks everyone over, F shows the collision shapes.
• 91 automated tests covering six rig conventions, three scales, hits and getting up.

Requirements

• Godot 4.7 (built and tested on 4.7.2). Pure GDScript.
• Jolt Physics: Project Settings → Physics → 3D → Physics Engine → Jolt Physics.

License

MIT: free to use, change and share in any project, free or commercial. Just keep the copyright notice. Demo model: KayKit Adventurers by Kay Lousberg (CC0).

Why PhysicalBone3D shrinks scaled characters, and how this fixes it: read the note on excalibug.com.

Made by Sir Debugalot · excalibug.com