AtomicGameEngine-Examples/FeatureExamples/CSharp/Resources/Components/Ragdoll.cs

//
// Copyright (c) 2008-2015 the Urho3D project.
// Copyright (c) 2015 Xamarin Inc
// Copyright (c) 2016 THUNDERBEAST GAMES LLC
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

using System;
using AtomicEngine;

namespace FeatureExamples
{
    class Ragdoll : CSComponent
    {
        public void Start()
        {
            SubscribeToEvent<NodeCollisionEvent>(Node, HandleNodeCollision);
            
        }

        void HandleNodeCollision(NodeCollisionEvent e)
        {
            // Get the other colliding body, make sure it is moving (has nonzero mass)
            RigidBody otherBody = e.OtherBody;

            if (otherBody.Mass > 0.0f)
            {
                // We do not need the physics components in the AnimatedModel's root scene node anymore
                Node.RemoveComponent<RigidBody>();
                Node.RemoveComponent<CollisionShape>();

                // Create RigidBody & CollisionShape components to bones
                CreateRagdollBone("Bip01_Pelvis", ShapeType.SHAPE_BOX, new Vector3(0.3f, 0.2f, 0.25f), new Vector3(0.0f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 0.0f));
                CreateRagdollBone("Bip01_Spine1", ShapeType.SHAPE_BOX, new Vector3(0.35f, 0.2f, 0.3f), new Vector3(0.15f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 0.0f));
                CreateRagdollBone("Bip01_L_Thigh", ShapeType.SHAPE_CAPSULE, new Vector3(0.175f, 0.45f, 0.175f), new Vector3(0.25f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_R_Thigh", ShapeType.SHAPE_CAPSULE, new Vector3(0.175f, 0.45f, 0.175f), new Vector3(0.25f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_L_Calf", ShapeType.SHAPE_CAPSULE, new Vector3(0.15f, 0.55f, 0.15f), new Vector3(0.25f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_R_Calf", ShapeType.SHAPE_CAPSULE, new Vector3(0.15f, 0.55f, 0.15f), new Vector3(0.25f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_Head", ShapeType.SHAPE_BOX, new Vector3(0.2f, 0.2f, 0.2f), new Vector3(0.1f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 0.0f));
                CreateRagdollBone("Bip01_L_UpperArm", ShapeType.SHAPE_CAPSULE, new Vector3(0.15f, 0.35f, 0.15f), new Vector3(0.1f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_R_UpperArm", ShapeType.SHAPE_CAPSULE, new Vector3(0.15f, 0.35f, 0.15f), new Vector3(0.1f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_L_Forearm", ShapeType.SHAPE_CAPSULE, new Vector3(0.125f, 0.4f, 0.125f), new Vector3(0.2f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));
                CreateRagdollBone("Bip01_R_Forearm", ShapeType.SHAPE_CAPSULE, new Vector3(0.125f, 0.4f, 0.125f), new Vector3(0.2f, 0.0f, 0.0f),
                    new Quaternion(0.0f, 0.0f, 90.0f));

                Vector3 back = new Vector3(0f, 0f, -1f);
                Vector3 forward = new Vector3(0f, 0f, 1f);
                Vector3 left = new Vector3(-1f, 0f, 0f);
                Vector3 down = new Vector3(0f, -1f, 0f);
                Vector3 up = new Vector3(0f, 1f, 0f);

                // Create Constraints between bones
                CreateRagdollConstraint("Bip01_L_Thigh", "Bip01_Pelvis", ConstraintType.CONSTRAINT_CONETWIST, back, forward,
                    new Vector2(45.0f, 45.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_R_Thigh", "Bip01_Pelvis", ConstraintType.CONSTRAINT_CONETWIST, back, forward,
                    new Vector2(45.0f, 45.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_L_Calf", "Bip01_L_Thigh", ConstraintType.CONSTRAINT_HINGE, back, back,
                    new Vector2(90.0f, 0.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_R_Calf", "Bip01_R_Thigh", ConstraintType.CONSTRAINT_HINGE, back, back,
                    new Vector2(90.0f, 0.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_Spine1", "Bip01_Pelvis", ConstraintType.CONSTRAINT_HINGE, forward, forward,
                    new Vector2(45.0f, 0.0f), new Vector2(-10.0f, 0.0f));
                CreateRagdollConstraint("Bip01_Head", "Bip01_Spine1", ConstraintType.CONSTRAINT_CONETWIST, left, left,
                    new Vector2(0.0f, 30.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_L_UpperArm", "Bip01_Spine1", ConstraintType.CONSTRAINT_CONETWIST, down, up,
                    new Vector2(45.0f, 45.0f), Vector2.Zero, false);
                CreateRagdollConstraint("Bip01_R_UpperArm", "Bip01_Spine1", ConstraintType.CONSTRAINT_CONETWIST, down, up,
                    new Vector2(45.0f, 45.0f), Vector2.Zero, false);
                CreateRagdollConstraint("Bip01_L_Forearm", "Bip01_L_UpperArm", ConstraintType.CONSTRAINT_HINGE, back, back,
                    new Vector2(90.0f, 0.0f), Vector2.Zero);
                CreateRagdollConstraint("Bip01_R_Forearm", "Bip01_R_UpperArm", ConstraintType.CONSTRAINT_HINGE, back, back,
                    new Vector2(90.0f, 0.0f), Vector2.Zero);

                // Disable keyframe animation from all bones so that they will not interfere with the ragdoll
                AnimatedModel model = GetComponent<AnimatedModel>();

                Skeleton skeleton = model.Skeleton;
                for (uint i = 0; i < skeleton.GetNumBones(); ++i)
                {
                    skeleton.GetBone(i).Animated = false;
                }

                // Finally remove self from the scene node. Note that this must be the last operation performed in the function
                Remove();
            }
        }

        void CreateRagdollBone(string boneName, ShapeType type, Vector3 size, Vector3 position, Quaternion rotation)
        {
            // Find the correct child scene node recursively
            Node boneNode = Node.GetChild(boneName, true);
            if (boneNode == null)
            {
                Log.Warn($"Could not find bone {boneName} for creating ragdoll physics components");
                return;
            }

            RigidBody body = boneNode.CreateComponent<RigidBody>();
            // Set mass to make movable
            body.Mass = 1.0f;
            // Set damping parameters to smooth out the motion
            body.LinearDamping = 0.05f;
            body.AngularDamping = 0.85f;
            // Set rest thresholds to ensure the ragdoll rigid bodies come to rest to not consume CPU endlessly
            body.LinearRestThreshold = 1.5f;
            body.AngularRestThreshold = 2.5f;

            CollisionShape shape = boneNode.CreateComponent<CollisionShape>();
            // We use either a box or a capsule shape for all of the bones
            if (type == ShapeType.SHAPE_BOX)
                shape.SetBox(size, position, rotation);
            else
                shape.SetCapsule(size.X, size.Y, position, rotation);
        }

        void CreateRagdollConstraint(string boneName, string parentName, ConstraintType type,
            Vector3 axis, Vector3 parentAxis, Vector2 highLimit, Vector2 lowLimit, bool disableCollision = true)
        {
            Node boneNode = Node.GetChild(boneName, true);
            Node parentNode = Node.GetChild(parentName, true);
            if (boneNode == null)
            {
                Log.Warn($"Could not find bone {boneName} for creating ragdoll constraint");
                return;
            }
            if (parentNode == null)
            {
                Log.Warn($"Could not find bone {parentName} for creating ragdoll constraint");
                return;
            }

            Constraint constraint = boneNode.CreateComponent<Constraint>();
            constraint.ConstraintType = type;
            // Most of the constraints in the ragdoll will work better when the connected bodies don't collide against each other
            constraint.DisableCollision = disableCollision;
            // The connected body must be specified before setting the world position
            constraint.OtherBody = parentNode.GetComponent<RigidBody>();
            // Position the constraint at the child bone we are connecting
            constraint.SetWorldPosition(boneNode.WorldPosition);
            // Configure axes and limits
            constraint.SetAxis(axis);
            constraint.SetOtherAxis(parentAxis);
            constraint.HighLimit = highLimit;
            constraint.LowLimit = lowLimit;
        }
    }
}