urho3d/Source/Samples/13_Ragdolls/CreateRagdoll.cpp

// Copyright (c) 2008-2022 the Urho3D project
// License: MIT

#include <Urho3D/Graphics/AnimatedModel.h>
#include <Urho3D/IO/Log.h>
#include <Urho3D/Physics/PhysicsEvents.h>
#include <Urho3D/Physics/RigidBody.h>

#include "CreateRagdoll.h"

#include <Urho3D/DebugNew.h>

CreateRagdoll::CreateRagdoll(Context* context) :
    Component(context)
{
}

void CreateRagdoll::OnNodeSet(Node* node)
{
    // If the node pointer is non-null, this component has been created into a scene node. Subscribe to physics collisions that
    // concern this scene node
    if (node)
        SubscribeToEvent(node, E_NODECOLLISION, URHO3D_HANDLER(CreateRagdoll, HandleNodeCollision));
}

void CreateRagdoll::HandleNodeCollision(StringHash eventType, VariantMap& eventData)
{
    using namespace NodeCollision;

    // Get the other colliding body, make sure it is moving (has nonzero mass)
    auto* otherBody = static_cast<RigidBody*>(eventData[P_OTHERBODY].GetPtr());

    if (otherBody->GetMass() > 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", SHAPE_BOX, Vector3(0.3f, 0.2f, 0.25f), Vector3(0.0f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 0.0f));
        CreateRagdollBone("Bip01_Spine1", SHAPE_BOX, Vector3(0.35f, 0.2f, 0.3f), Vector3(0.15f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 0.0f));
        CreateRagdollBone("Bip01_L_Thigh", SHAPE_CAPSULE, Vector3(0.175f, 0.45f, 0.175f), Vector3(0.25f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_R_Thigh", SHAPE_CAPSULE, Vector3(0.175f, 0.45f, 0.175f), Vector3(0.25f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_L_Calf", SHAPE_CAPSULE, Vector3(0.15f, 0.55f, 0.15f), Vector3(0.25f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_R_Calf", SHAPE_CAPSULE, Vector3(0.15f, 0.55f, 0.15f), Vector3(0.25f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_Head", SHAPE_BOX, Vector3(0.2f, 0.2f, 0.2f), Vector3(0.1f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 0.0f));
        CreateRagdollBone("Bip01_L_UpperArm", SHAPE_CAPSULE, Vector3(0.15f, 0.35f, 0.15f), Vector3(0.1f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_R_UpperArm", SHAPE_CAPSULE, Vector3(0.15f, 0.35f, 0.15f), Vector3(0.1f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_L_Forearm", SHAPE_CAPSULE, Vector3(0.125f, 0.4f, 0.125f), Vector3(0.2f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));
        CreateRagdollBone("Bip01_R_Forearm", SHAPE_CAPSULE, Vector3(0.125f, 0.4f, 0.125f), Vector3(0.2f, 0.0f, 0.0f),
            Quaternion(0.0f, 0.0f, 90.0f));

        // Create Constraints between bones
        CreateRagdollConstraint("Bip01_L_Thigh", "Bip01_Pelvis", CONSTRAINT_CONETWIST, Vector3::BACK, Vector3::FORWARD,
            Vector2(45.0f, 45.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_R_Thigh", "Bip01_Pelvis", CONSTRAINT_CONETWIST, Vector3::BACK, Vector3::FORWARD,
            Vector2(45.0f, 45.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_L_Calf", "Bip01_L_Thigh", CONSTRAINT_HINGE, Vector3::BACK, Vector3::BACK,
            Vector2(90.0f, 0.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_R_Calf", "Bip01_R_Thigh", CONSTRAINT_HINGE, Vector3::BACK, Vector3::BACK,
            Vector2(90.0f, 0.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_Spine1", "Bip01_Pelvis", CONSTRAINT_HINGE, Vector3::FORWARD, Vector3::FORWARD,
            Vector2(45.0f, 0.0f), Vector2(-10.0f, 0.0f));
        CreateRagdollConstraint("Bip01_Head", "Bip01_Spine1", CONSTRAINT_CONETWIST, Vector3::LEFT, Vector3::LEFT,
            Vector2(0.0f, 30.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_L_UpperArm", "Bip01_Spine1", CONSTRAINT_CONETWIST, Vector3::DOWN, Vector3::UP,
            Vector2(45.0f, 45.0f), Vector2::ZERO, false);
        CreateRagdollConstraint("Bip01_R_UpperArm", "Bip01_Spine1", CONSTRAINT_CONETWIST, Vector3::DOWN, Vector3::UP,
            Vector2(45.0f, 45.0f), Vector2::ZERO, false);
        CreateRagdollConstraint("Bip01_L_Forearm", "Bip01_L_UpperArm", CONSTRAINT_HINGE, Vector3::BACK, Vector3::BACK,
            Vector2(90.0f, 0.0f), Vector2::ZERO);
        CreateRagdollConstraint("Bip01_R_Forearm", "Bip01_R_UpperArm", CONSTRAINT_HINGE, Vector3::BACK, Vector3::BACK,
            Vector2(90.0f, 0.0f), Vector2::ZERO);

        // Disable keyframe animation from all bones so that they will not interfere with the ragdoll
        auto* model = GetComponent<AnimatedModel>();
        Skeleton& skeleton = model->GetSkeleton();
        for (unsigned 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 CreateRagdoll::CreateRagdollBone(const String& boneName, ShapeType type, const Vector3& size, const Vector3& position,
    const Quaternion& rotation)
{
    // Find the correct child scene node recursively
    Node* boneNode = node_->GetChild(boneName, true);
    if (!boneNode)
    {
        URHO3D_LOGWARNING("Could not find bone " + boneName + " for creating ragdoll physics components");
        return;
    }

    auto* body = boneNode->CreateComponent<RigidBody>();
    // Set mass to make movable
    body->SetMass(1.0f);
    // Set damping parameters to smooth out the motion
    body->SetLinearDamping(0.05f);
    body->SetAngularDamping(0.85f);
    // Set rest thresholds to ensure the ragdoll rigid bodies come to rest to not consume CPU endlessly
    body->SetLinearRestThreshold(1.5f);
    body->SetAngularRestThreshold(2.5f);

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

void CreateRagdoll::CreateRagdollConstraint(const String& boneName, const String& parentName, ConstraintType type,
    const Vector3& axis, const Vector3& parentAxis, const Vector2& highLimit, const Vector2& lowLimit,
    bool disableCollision)
{
    Node* boneNode = node_->GetChild(boneName, true);
    Node* parentNode = node_->GetChild(parentName, true);
    if (!boneNode)
    {
        URHO3D_LOGWARNING("Could not find bone " + boneName + " for creating ragdoll constraint");
        return;
    }
    if (!parentNode)
    {
        URHO3D_LOGWARNING("Could not find bone " + parentName + " for creating ragdoll constraint");
        return;
    }

    auto* constraint = boneNode->CreateComponent<Constraint>();
    constraint->SetConstraintType(type);
    // Most of the constraints in the ragdoll will work better when the connected bodies don't collide against each other
    constraint->SetDisableCollision(disableCollision);
    // The connected body must be specified before setting the world position
    constraint->SetOtherBody(parentNode->GetComponent<RigidBody>());
    // Position the constraint at the child bone we are connecting
    constraint->SetWorldPosition(boneNode->GetWorldPosition());
    // Configure axes and limits
    constraint->SetAxis(axis);
    constraint->SetOtherAxis(parentAxis);
    constraint->SetHighLimit(highLimit);
    constraint->SetLowLimit(lowLimit);
}