如何使我的物理对象稳定下来？

Question

我正在使用BulletSharp，它是bullet库的C#版本。我发现一个物体在"弹力"Restitution值为0.0f时仍然出现了反弹。

我有一个动态圆柱体（不久将成为网格），它落到了两个静态圆柱体上。像这样: 通常情况下，顶部的圆柱体会猛烈地弹跳，并经常向一侧弹跳。

这是我用来设置场景的代码:

        //now figure out bulletsharp stuff...
        CollisionConfiguration collConfig = new DefaultCollisionConfiguration();
        Dispatcher collDispatch = new CollisionDispatcher(collConfig);

        BroadphaseInterface broadphase = new DbvtBroadphase();
        ConstraintSolver sol = new SequentialImpulseConstraintSolver();
        world = new DiscreteDynamicsWorld(collDispatch, broadphase, sol, collConfig);

        world.Gravity = new Vector3(0.0f, -10.0f, 0.0f);

        //log (moving object)
        MotionState still = new DefaultMotionState();
        CylinderShape shape = new CylinderShapeZ(0.5f, 1.0f, 1.0f);
        still.WorldTransform = Matrix.Translation(0.0f, 0.4f, 0.0f);
        RigidBodyConstructionInfo constructInfo = new RigidBodyConstructionInfo(1.0f, still, shape);
        logBody = new RigidBody(constructInfo);
        logBody.SetDamping(0.04f, 0.1f);
        world.AddRigidBody(logBody);

        //rollers (static objects)
        CylinderShape r1s = new CylinderShapeZ(0.1f, 1.0f, 1.0f);
        MotionState r1m = new DefaultMotionState();
        r1m.WorldTransform = Matrix.Translation(-0.2f, -0.4f, 0.0f);
        RigidBodyConstructionInfo r1ci = new RigidBodyConstructionInfo(0.0f, r1m, r1s);
        r1 = new RigidBody(r1ci);
        world.AddRigidBody(r1);

        CylinderShape r2s = new CylinderShapeZ(0.1f, 1.0f, 1.0f);
        MotionState r2m = new DefaultMotionState();
        r2m.WorldTransform = Matrix.Translation(0.2f, -0.4f, 0.0f);
        RigidBodyConstructionInfo r2ci = new RigidBodyConstructionInfo(0.0f, r2m, r2s);
        r2 = new RigidBody(r2ci);
        world.AddRigidBody(r2);

每一帧中我使用world.StepSimulation(0.05f, 100, 0.0005f);来更新物理模拟。

我是否缺少任何明显的设置？为什么我的模拟会出现这种情况？

小更新：我已经成功地在Blender的Bullet模拟中制作了一个类似的模拟。那里没有弹跳...我不知道那里和这里之间可能有什么区别。

- tugs

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你能给下落的物体添加恢复力吗？ - MoonKnight

仅将恢复系数添加到掉落物体并没有产生任何显着的差异。将所有三个物体的恢复系数设置为0.1似乎有点稳定了，但这取决于模拟步长。偶尔还有一些反弹，时而会弹开。 - tugs

Answer 1

您没有将惯性添加到您的模型中。这应该能够减缓抖动并且不会产生反弹，最终导致其弹回滚轮上。您需要为包括滚轮上的零件在内的所有三个对象添加它。请尝试此操作并告诉我它的效果如何：

//now figure out bulletsharp stuff...
CollisionConfiguration collConfig = new DefaultCollisionConfiguration();
Dispatcher collDispatch = new CollisionDispatcher(collConfig);

BroadphaseInterface broadphase = new DbvtBroadphase();
ConstraintSolver sol = new SequentialImpulseConstraintSolver();
world = new DiscreteDynamicsWorld(collDispatch, broadphase, sol, collConfig);

world.Gravity = new Vector3(0.0f, -10.0f, 0.0f);

//log (moving object)
Vector3 cylinderInertia;
MotionState still = new DefaultMotionState();
CylinderShape shape = new CylinderShapeZ(0.5f, 1.0f, 1.0f);
still.WorldTransform = Matrix.Translation(0.0f, 0.4f, 0.0f);
shape.CalculateLocalInertia(1.0f, out cylinderInertia);    
RigidBodyConstructionInfo constructInfo = new RigidBodyConstructionInfo(1.0f, still, shape, cylinderInertia);
logBody = new RigidBody(constructInfo);
logBody.SetDamping(0.04f, 0.1f);
world.AddRigidBody(logBody);

//rollers (static objects)
CylinderShape r1s = new CylinderShapeZ(0.1f, 1.0f, 1.0f);
MotionState r1m = new DefaultMotionState();
r1m.WorldTransform = Matrix.Translation(-0.2f, -0.4f, 0.0f);
RigidBodyConstructionInfo r1ci = new RigidBodyConstructionInfo(0.0f, r1m, r1s, Vector3.Zero);
r1 = new RigidBody(r1ci);
world.AddRigidBody(r1);

CylinderShape r2s = new CylinderShapeZ(0.1f, 1.0f, 1.0f);
MotionState r2m = new DefaultMotionState();
r2m.WorldTransform = Matrix.Translation(0.2f, -0.4f, 0.0f);
RigidBodyConstructionInfo r2ci = new RigidBodyConstructionInfo(0.0f, r2m, r2s, Vector3.Zero);
r2 = new RigidBody(r2ci);
world.AddRigidBody(r2);

- MrWuf