Question

我使用bulletsharp（子弹物理的C＃包装器）进行一些碰撞检测。一切都很顺利，直到我试图在运行时将现有刚体的碰撞形状从盒子改为复合。我这样做是为了再次以更高的精度模拟碰撞。问题是：未检测到复合形状的碰撞。

情境：

DicreteDynamicsWorld包含一些RigidBody与BoxShape
两个运动RigidBody与BoxShape的碰撞发生（并被检测到）
使用HACD算法进行凸分解，将这两个RigidBody的形状更改为CompoundShape
从RigidBody

DicreteDynamicsWorld

RigidBody.CollisionShape = CompoundShape
使用RigidBody.MotionState.WorldTransform
将RigidBody添加到DicreteDynamicsWorld
撤消导致碰撞的移动（一个物体不包含另一个物体）
重复动作
未检测到碰撞

说明：

将CollisionShape从BoxShape更改为CompoundShape成功（正确CollisionShape和正确位置）
对于碰撞检测，我在DicreteDynamicsWorld.Dispatcher.NumManifolds > 0

DicreteDynamicsWorld.StepSimulation(...)

根据要求提供了一些代码段：

如果您需要特别的东西，请告诉我。我的解决方案太大而且太复杂，无法发布完整的代码......

RigidBody创作：

// Create rigid body
MotionState motionState = new DefaultMotionState(startTransform);
RigidBodyConstructionInfo rbInfo = new RigidBodyConstructionInfo(0.0f, motionState, collisionShape);
RigidBody rigidBody = new RigidBody(rbInfo);
rbInfo.Dispose();

// Kinematic body: mass=0 -> static/kinematic -> use flag
bool isKinematicBody = (compModel.Children[i].Type ==...) || ... ;
rigidBody.CollisionFlags = isKinematicBody ? CollisionFlags.KinematicObject : CollisionFlags.StaticObject;
rigidBody.ActivationState = ActivationState.DisableDeactivation;

基本步骤：

// Get old collision data
if (compModel.Children[i].Container.TryGetValue(ContainerType.Collision, out container))
    collisionData = ((ContainerCollision) container).CollisionData;

// Get geometry
if (compModel.Children[i].Container.TryGetValue(ContainerType.Geometry, out container))
{
    verticesGeo = ((ContainerGeometry) container).GeometryData.Vertices;
    trianglesGeo = ((ContainerGeometry) container).GeometryData.Triangles;
}

// Remove rigid body from world
_world.RemoveRigidBody(collisionData.RigidBody);

// Create new shape
List<Vector3> vertices = Utility.ToBulletVector3List(verticesGeo);
List<int> indices = Utility.ListIntArrayToListInt(trianglesGeo);
CompoundShape collisionShape = ConvexDecomposition(compModel.Children[i].Id, vertices, indices);

// Set collision shape
collisionData.RigidBody.CollisionShape = collisionShape;

// Set position
collisionData.RigidBody.MotionState.WorldTransform *= collisionData.PositionDifference;

// Add rigid body to world
_world.AddRigidBody(collisionData.RigidBody, collisionData.CollisionGroup, collisionData.CollisionMask);

CollisionContainer：

public interface IContainer
{
    ContainerType Type { get; }
}

public struct ContainerCollision : IContainer
{
    public ContainerType Type
    {
        get { return ContainerType.Collision; }
    }

    public CollisionData CollisionData;
}

结构碰撞数据：

public struct CollisionData
{
    public BulletSharp.RigidBody RigidBody;
    public BulletSharp.Matrix PositionDifference;
    public BulletSharp.Vector3 ZeroPosition;
    public short CollisionGroup;
    public short CollisionMask;
}

任何想法，我做错了什么？

感谢。

Answer 1

假设你的形状发生了变化

CompoundShape collisionShape = ConvexDecomposition(compModel.Children[i].Id, vertices, indices);

// Set collision shape
collisionData.RigidBody.CollisionShape = collisionShape;

// Set position
collisionData.RigidBody.MotionState.WorldTransform *= collisionData.PositionDifference;

    // Add rigid body to world
_world.AddRigidBody(collisionData.RigidBody, collisionData.CollisionGroup, collisionData.CollisionMask);

可能你必须从一开始就重新计算整个RigidBody，我不知道你是怎么做到的，所以我会告诉你一个例子我是怎么做的。

public virtual RigidBody LocalCreateRigidBody(float mass, Matrix startTransform, CollisionShape shape)
        {

            //rigidbody is dynamic if and only if mass is non zero, otherwise static
            bool isDynamic = (mass != 0.0f);

            Vector3 localInertia = Vector3.Zero;
            if (isDynamic)
                shape.CalculateLocalInertia(mass, out localInertia);

            //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
            DefaultMotionState myMotionState = new DefaultMotionState(startTransform);

            RigidBodyConstructionInfo rbInfo = new RigidBodyConstructionInfo(mass, myMotionState, shape, localInertia);
            RigidBody body = new RigidBody(rbInfo);
            rbInfo.Dispose();


            return body;
        }

话虽如此，请记下你的“collisionData”（我猜它是一个类？）和RigidBody的命名（它可能与BulletSharp类有冲突？）

对您的进步有最好的指导，如果您有任何问题，请随时与我联系！

子弹物理碰撞检测

1 个答案: