我尝试了此处发布的解决方案,但没有解决问题。没有人回复我的请求,因为该问题已被标记为已回答。
我让玩家跳过屏幕抓住绳子。SKPhysicsJointPin
通过在绳索段和玩家之间建立连接来实现抓取。绳索本身是由许多用 s 相互连接的线段组成SKPhysicsJointPin
的。那些行为符合预期。然而,玩家似乎被连接了大约一秒钟,但是当玩家和绳索一起摆动时,他们之间的关节伸展并且玩家完全从屏幕上掉下来。
这是玩家(一只猴子)被添加到场景中的地方:
- (void)addMonkeyToWorld
{
SKSpriteNode *monkeySpriteNode = [SKSpriteNode spriteNodeWithImageNamed:@"Monkey"];
// Basic properties
monkeySpriteNode.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:monkeySpriteNode.size];
monkeySpriteNode.physicsBody.density = physicsParameters.monkeyDensity;
monkeySpriteNode.physicsBody.restitution = physicsParameters.monkeyRestitution;
monkeySpriteNode.physicsBody.linearDamping = physicsParameters.monkeyLinearDamping;
monkeySpriteNode.physicsBody.angularDamping = physicsParameters.monkeyAngularDamping;
monkeySpriteNode.physicsBody.velocity = physicsParameters.monkeyInitialVelocity;
// Collision properties
monkeySpriteNode.physicsBody.categoryBitMask = monkeyCategory;
monkeySpriteNode.physicsBody.contactTestBitMask = ropeCategory;
monkeySpriteNode.physicsBody.collisionBitMask = 0x0;
monkeySpriteNode.physicsBody.usesPreciseCollisionDetection = YES;
}
这里是一个联系人事件被整理的地方:
- (void)didBeginContact:(SKPhysicsContact *)contact
{
// Sort which bodies are which
SKPhysicsBody *firstBody, *secondBody;
if (contact.bodyA.categoryBitMask > contact.bodyB.categoryBitMask) {
firstBody = contact.bodyA;
secondBody = contact.bodyB;
}
else {
firstBody = contact.bodyB;
secondBody = contact.bodyA;
}
// Verify that the two bodies were the monkey and rope, then handle collision
if ((firstBody.categoryBitMask & ropeCategory) != 0 && (secondBody.categoryBitMask & monkeyCategory) != 0)
{
[self monkey:secondBody didCollideWithRope:firstBody atPoint:contact.contactPoint];
}
}
这是在玩家和绳索之间添加关节的地方:
- (void)monkey:(SKPhysicsBody *)monkeyPhysicsBody didCollideWithRope:(SKPhysicsBody *)ropePhysicsBody atPoint:(CGPoint)contactPoint
{
if (monkeyPhysicsBody.joints.count == 0) {
// Create a new joint between the monkey and the rope segment
CGPoint convertedMonkeyPosition = CGPointMake(monkeyPhysicsBody.node.position.x + sceneWidth/2., monkeyPhysicsBody.node.position.y + sceneHeight/2.);
CGPoint convertedRopePosition = CGPointMake(ropePhysicsBody.node.position.x + sceneWidth/2., ropePhysicsBody.node.position.y + sceneHeight/2.);
CGFloat leftMostX = convertedMonkeyPosition.x < convertedRopePosition.x ? convertedMonkeyPosition.x : convertedRopePosition.x;
CGFloat bottomMostY = convertedMonkeyPosition.y < convertedRopePosition.y ? convertedMonkeyPosition.y : convertedRopePosition.y;
CGPoint midPointMonkeyAndRope = CGPointMake(leftMostX + fabsf(ropePhysicsBody.node.position.x - monkeyPhysicsBody.node.position.x) / 2.,
bottomMostY + fabsf(ropePhysicsBody.node.position.y - monkeyPhysicsBody.node.position.y) / 2.);
SKPhysicsJointPin *jointPin = [SKPhysicsJointPin jointWithBodyA:monkeyPhysicsBody bodyB:ropePhysicsBody anchor:midPointMonkeyAndRope]; // FIXME: Monkey-rope joint going to weird position
jointPin.upperAngleLimit = M_PI/4;
jointPin.shouldEnableLimits = YES;
[self.scene.physicsWorld addJoint:jointPin];
}
}
有什么想法会导致SKPhysicsJointPin
伸展吗?