Cocos2d iphone 动态更改box2d实体形状

是否可以动态更改Box2d B2B车身的形状？我想这样做是为了实现以下目标

i） 。以一定的速度增加圆形的半径

(ii)。更改精灵边界框的尺寸以匹配更改的动画帧

   float radius;
   radius = 1;

创建主体：

b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(300/PTM_RATIO, 150/PTM_RATIO);
body = world->CreateBody(&bodyDef);

b2CircleShape circleShape;
circleShape.m_radius = radius;

b2FixtureDef fixtureDef;
fixtureDef.shape = &circleShape;
fixtureDef.density = 1;
fixtureDef.friction = 0.3f;
body ->CreateFixture(&fixtureDef);

在您的触摸方式中：

  - (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
   {  

    if (body != NULL) {

    b2Fixture *fixtureA = body->GetFixtureList();
    body->DestroyFixture(fixtureA);

    b2CircleShape circleShape;
    circleShape.m_radius = radius + 0.3; 

    b2FixtureDef fixtureDef;
    fixtureDef.shape = &circleShape;
    fixtureDef.density = 1;
    fixtureDef.friction = 0.3f;
    body->CreateFixture(&fixtureDef);

    radius = radius + 0.3;

   }

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每触摸一次，车身将变大0.3。

您无法动态更改box2d b2body的形状，但您可以通过销毁和重新创建b2body来实现。您只需要重新创建夹具，而不是整个车身是的，我的错误，我正要说，但写了b2body。您只需重新创建夹具即可。@learncos2D:+1以获取此示例。