iphone - 如何让一个 b2Body 忽略另一个 b2Body？

Question

我有三个 b2Body-s。头部、下巴和一个静态类型的 b2Body。我从静态 b2Body 添加一个 b2Joint 到头部，另一个 b2Joint 用于头部和下巴。头部忽略静态 body ，因为关节的 collideConnected 为 false，但下巴不会忽略它。怎么做这个？请提出建议。

Answer 1

enum CATEGORY_BITS
{
    BODY1_CATEGORY_BITS = 0x00000001,
    BODY2_CATEGORY_BITS = 0x00000002,
    BODY3_CATEGORY_BITS = 0x00000004,

};

当你创建 body 时......

    b2FixtureDef fixtureForBODY1;
    fixtureForBODY1.shape = &shapeForBODY1;
    fixtureForBODY1.filter.categoryBits = BODY1_CATEGORY_BITS;
    fixtureForBODY1.filter.maskBits = BODY1_CATEGORY_BITS | BODY3_CATEGORY_BITS;


    b2FixtureDef fixtureForBODY2;
    fixtureForBODY2.shape = &shapeForBODY2;
    fixtureForBODY2.filter.categoryBits = BODY2_CATEGORY_BITS;
    fixtureForBODY2.filter.maskBits = BODY2_CATEGORY_BITS | BODY4_CATEGORY_BITS;

    b2FixtureDef fixtureForBODY3;
    fixtureForBODY3.shape = &shapeForBODY3;
    fixtureForBODY3.filter.categoryBits = BODY3_CATEGORY_BITS;
    fixtureForBODY3.filter.maskBits = BODY3_CATEGORY_BITS | BODY1_CATEGORY_BITS;

    b2FixtureDef fixtureForBODY4;
    fixtureForBODY4.shape = &shapeForBODY4;
    fixtureForBODY4.filter.categoryBits = BODY4_CATEGORY_BITS;
    fixtureForBODY4.filter.maskBits = BODY4_CATEGORY_BITS | BODY2_CATEGORY_BITS;



// BODY1 -> not collide connected (BODY2 and BODY4)
// BODY1 -> collide connected (BODY1 and BODY3)