B2body 在撞击传感器时向上移动而不是在直线路径上行走

Posted 2023-03-11

【中文标题】B2body 在撞击传感器时向上移动而不是在直线路径上行走

【英文标题】：B2body moving up when hitting sensor rather than walking on straight path

【发布时间】：2013-11-11 06:26:05

【问题描述】：

我有一些昆虫在路上行走，我也添加了传感器。 当它与身体碰撞时，它会破坏身体并且工作正常。

但是当球击中昆虫的传感器时，有时我的昆虫身体开始向上移动。

在打昆虫之前

击中昆虫后

这是我的昆虫身体代码实现

    -(b2Body *) createMovingAntObstacle  :(int) sPosX startPositionY :(int) sPosY transitionTime:(float)speed

    NSLog(@"TAG_ANT");
    //set this to avoid updating this object in the tick schedule
    _currentAnimatedSprite.userData = (void *)YES;

    b2BodyDef bodyDef_Ant;
    bodyDef_Ant.type = b2_dynamicBody;
    CGPoint startPos = ccp(520,winSize.height/7);
    bodyDef_Ant.position = [self toMeters:startPos];
    bodyDef_Ant.userData = _currentAnimatedSprite;
    bodyDef_Ant.gravityScale = 0;

    b2PolygonShape dynamicBox;

    int num = 5;
    b2Vec2 verts[] = 
        b2Vec2(-19.0f / PTM_RATIO, 1.4f / PTM_RATIO),
        b2Vec2(-18.5f / PTM_RATIO, -4.0f / PTM_RATIO),
        b2Vec2(8.8f / PTM_RATIO, -3.7f / PTM_RATIO),
        b2Vec2(7.9f / PTM_RATIO, 2.1f / PTM_RATIO),
        b2Vec2(-18.5f / PTM_RATIO, 1.8f / PTM_RATIO)
    ;

    dynamicBox.Set(verts, num);

    b2FixtureDef fixtureDef_Ant;
    fixtureDef_Ant.shape = &dynamicBox;
    fixtureDef_Ant.friction = 0.7;
    fixtureDef_Ant.density = 10.0f;
    fixtureDef_Ant.restitution = 0.7;

    antBody = world->CreateBody(&bodyDef_Ant);
    antBody->CreateFixture(&fixtureDef_Ant);

    /*** Begin Tutorial Code ***/
    b2Filter defaultFilter = antBody->GetFixtureList()[0].GetFilterData();

    defaultFilter.groupIndex = k_indexD; // Negative index (Never collides with same Index group objects)
    defaultFilter.categoryBits = k_dCategory;
    defaultFilter.maskBits = k_dMask; // HITS EVERYTHING EXCEPT A & C

    antBody->GetFixtureList()[0].SetFilterData(defaultFilter);

    float padding = 1.0f;

    // RIGHT SENSOR

    b2PolygonShape shape2;

    int num2= 4;
    b2Vec2 vertices2[] = 
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 2 ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / 20 ) / PTM_RATIO), //top right corner (borders source image)
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 2 ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / -4 )/ PTM_RATIO), //bottom right corner (borders source image)
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 1.9  * padding ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / -4 )/ PTM_RATIO), //bottom right corner (farthest out
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 1.9 * padding ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / 20 ) / PTM_RATIO) //top right
    ;

    shape2.Set(vertices2, num2);

    // Define the dynamic body fixture.
    b2FixtureDef fixtureDef2;
    fixtureDef2.shape = &shape2;
    fixtureDef2.density = 0.0f;
    fixtureDef2.friction = 0.0f;
    fixtureDef2.restitution =  0.0;
    fixtureDef2.isSensor = YES;
    fixtureDef2.userData = (SensorTypes*) rightSensor;

    antBody-> CreateFixture(&fixtureDef2);

    //add a new fixture as LEFT sensor

    b2PolygonShape shape3;


    int num3 = 4;
    b2Vec2 vertices3[] = 
        b2Vec2( (_currentAnimatedSprite.contentSize.width / -2 ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / -4 ) / PTM_RATIO), //bottom left corner (borders source image)
        b2Vec2( (_currentAnimatedSprite.contentSize.width / -2 ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / 20 ) / PTM_RATIO), //top left corner (borders source image)
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 1.9 * -padding ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / 20 ) / PTM_RATIO), //top left corner
        b2Vec2( (_currentAnimatedSprite.contentSize.width / 1.9 * -padding ) / PTM_RATIO, (_currentAnimatedSprite.contentSize.height / -4 ) / PTM_RATIO), //bottom left corner
    ;

    shape3.Set(vertices3, num3);

    // Define the dynamic body fixture.
    b2FixtureDef fixtureDef3;
    fixtureDef3.shape = &shape3;
    fixtureDef3.density = 0.1f;
    fixtureDef3.isSensor = YES;
    fixtureDef3.userData = (SensorTypes*) leftSensor;

    antBody-> CreateFixture(&fixtureDef3);

    VAMovingObstacle* moveableObject = [[VAMovingObstacle alloc] init];
    moveableObject.startPoint = ccp(sPosX,sPosY);
    moveableObject.endPoint = ccp(-100,sPosY);
    moveableObject.transitionTime = speed;
    moveableObject.breakTime = 1.0;
    moveableObject.obstacleSprite = _currentAnimatedSprite;
    moveableObject.physicalBody = antBody;
    [moveableObject addAnimation:_currentWalkAction];
    [moveableObject addMovement];

    if (!movingObstacles_Ant) 
        movingObstacles_Ant = [[NSMutableArray alloc] init];
    
    [movingObstacles_Ant addObject:moveableObject];
    //[moveableObject release];
    return antBody;

我是否必须改变密度、摩擦力或恢复力才能使其发挥作用？

【参考方案1】：

这个很简单我的朋友....我遇到了同样的问题...

去联系Listener类...

必要时这样做

 if ((bodyA->GetFixtureList()->GetFilterData().categoryBits == kCategoryBitsCharacter || bodyA->GetFixtureList()->GetFilterData().categoryBits == kCategoryBitsBurger) && (bodyB->GetFixtureList()->GetFilterData().categoryBits == kCategoryBitsBurger || bodyB->GetFixtureList()->GetFilterData().categoryBits == kCategoryBitsCharacter)) 
    contact->SetEnabled(false);

它对我有帮助...希望对你也有帮助