Box2D无法设置密度

Question

我试着用Box2D搞定。我可以编译我的程序但是当我尝试运行时出现错误。这是代码：

bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(x, y);
body = world.CreateBody(&bodyDef);
b2PolygonShape dynamicBox;
dynamicBox.SetAsBox(w, h);
b2FixtureDef fixtureDef;
fixtureDef.shape = &dynamicBox;
fixtureDef.density = 1.0f;
fixtureDef.friction = 0.3f;
body->CreateFixture(&fixtureDef);

错误：

mezo: ~/cpp/Box2D_v2.2.1/Box2D/Collision/Shapes/b2PolygonShape.cpp:352: virtual void b2PolygonShape::ComputeMass(b2MassData*, float32) const: Assertion `area > 1.19209289550781250000e-7F' failed.

我想出是否注释出fixtureDef.density = 1.0f;我可以编译，运行并且一切正常，除了身体快速移动2（因为密度可能？），如果我将密度设置为0，它也可以工作。

Answer 1

看起来你的形状区域非常小。检查w, h值。身体的速度与它的密度无关。