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我正在使用 box2d 2.1.2 和 cocos2d 0.99.4

在我的世界里，一切都很轻，没有丢石头或丢盒子的感觉！！一切都以同样的速度缓慢下落

b2Vec2 gravity; 
gravity.Set(0.0f, -10.0f);
bool doSleep = true;
world = new b2World(gravity, doSleep);

和我的对象：

b2BodyDef *TBodyDef = new b2BodyDef;
    TBodyDef->position.Set(100, 200);
    b2Body *TBody = world->CreateBody(TBodyDef);
    TBody->SetType(b2_dynamicBody);
    TBody->SetAwake(true);
    b2CircleShape TCircleShape;
    TCircleShape.m_radius = 20;
    b2FixtureDef TFixtureDef;
    TFixtureDef.shape = &TCircleShape;
    TFixtureDef.friction = 0.1;
    TFixtureDef.density = 0.1;
    TFixtureDef.restitution = 1;
    TFixtureDef.filter.categoryBits = COLLISION_BIT_GP;
    TFixtureDef.filter.maskBits = COLLISION_BIT_TERRAIN;
    TBody->CreateFixture(&TFixtureDef);

    b2BodyDef *TBodyDef1 = new b2BodyDef;
    TBodyDef1->position.Set(200, 200);
    b2Body *TBody1 = world->CreateBody(TBodyDef1);
    TBody1->SetType(b2_dynamicBody);
    TBody1->SetAwake(true);
    b2CircleShape TCircleShape1;
    TCircleShape1.m_radius = 20;
    b2FixtureDef TFixtureDef1;
    TFixtureDef1.shape = &TCircleShape;
    TFixtureDef1.friction = 0.1;
    TFixtureDef1.density = 0.5;
    TFixtureDef1.restitution = 1;
    TFixtureDef1.filter.categoryBits = COLLISION_BIT_GP;
    TFixtureDef1.filter.maskBits = COLLISION_BIT_TERRAIN;
    TBody1->CreateFixture(&TFixtureDef1);

我的步骤：

int32 velocityIterations = 8;
int32 positionIterations = 3;

world->Step(dt, velocityIterations, positionIterations);

密度不会改变下落的速度。缺少什么使它像这样流畅： 链接文本

谢谢您的帮助

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1 回答 1

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物体密度不会影响它下落的速度。

消除空气阻力和其他通常可以忽略不计的影响，所有物体都以相同的速度下落。

如何测试：拿起轻的东西（例如你朋友的 iPhone 4）和重的东西（你的旧 CRT），同时把它们扔出窗外。

于 2010-10-11T10:38:07.873 回答