在来自的帮助下here https://stackoverflow.com/questions/32352886/how-to-set-physics-properties-for-a-circle-so-it-follows-given-path我已经制作了一个圆形物体穿过给定的路径。我在某些路径点有一些尸体并已记录联系信息didBeginContact。当物体与特定物体接触时，圆形物体会变成矩形。该矩形体应该与原始圆形体经过相同的路径，但由于未记录接触，因此它不会到达路径点。我尝试改变radiusPoint也到矩形的宽度或高度，但这不起作用。而且矩形体比圆形体大。如何让矩形遍历识别出接触的点？请参阅下面的代码。
路径遍历相关代码：
let repeats: Bool = true //Whether to repeat the path.
var pathIndex = 0 //The index of the current point to travel.
var pointRadius: CGFloat = SKTexture(imageNamed: "circle").size().width //How close the node must be to reach the destination point.
let travelSpeed: CGFloat = 250 //Speed the node will travel at.
let rate: CGFloat = 0.9 //Motion smoothing. 0.5
circlePath = [
CGPoint(x:screenSize.width , y: screenSize.height/3),
CGPoint(x: screenSize.width/2, y: platform.sprite.frame.height),
CGPoint(x: 0.0, y: screenSize.height/3),
CGPoint(x: CGFloat(pos1) + screenSize.width/20, y: upperSpearPosHeight)]
final func didReachPoint() {
//reached point!
pathIndex++
if pathIndex >= ballPath.count && repeats {
pathIndex = 0
}
}
func updatePath() {
if pathIndex >= 0 && pathIndex < circlePath.count {
let destination = circlePath[pathIndex]
//currentPosition = destination
let displacement = CGVector(dx: destination.x-circle!.sprite.position.x, dy: destination.y-circle!.sprite.position.y)
let radius = sqrt(displacement.dx*displacement.dx+displacement.dy*displacement.dy)
let normal = CGVector(dx: displacement.dx/radius, dy: displacement.dy/radius)
let impulse = CGVector(dx: normal.dx*travelSpeed, dy: normal.dy*travelSpeed)
let relativeVelocity = CGVector(dx:impulse.dx-circle!.sprite.physicsBody!.velocity.dx, dy:impulse.dy-circle!.sprite.physicsBody!.velocity.dy);
circle!.sprite.physicsBody!.velocity=CGVectorMake(circle!.sprite.physicsBody!.velocity.dx+relativeVelocity.dx*rate, circle!.sprite.physicsBody!.velocity.dy+relativeVelocity.dy*rate);
if radius < pointRadius {
didReachPoint()
}
}
}
联系代码：
func didBeginContact(contact: SKPhysicsContact) {
var firstBody : SKPhysicsBody
var secondBody : SKPhysicsBody
if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
firstBody = contact.bodyA
secondBody = contact.bodyB
}
else {
firstBody = contact.bodyB
secondBody = contact.bodyA
}
if firstBody.categoryBitMask == circleCategory && secondBody.categoryBitMask == bonusCategory {
let img = SKTexture(imageNamed: "rectangular")
(firstBody.node! as? SKSpriteNode)?.size = img.size()
firstBody.node!.physicsBody = SKPhysicsBody(texture: img, size: img.size())
firstBody.node!.physicsBody?.allowsRotation = false
changeCircleAction = SKAction.setTexture(img)
firstBody.node!.runAction(changeCircleAction)
}
if firstBody.categoryBitMask == circleCategory && secondBody.categoryBitMask == platformCategory {
print("touched platform")
}
if firstBody.categoryBitMask == circleCategory && secondBody.categoryBitMask == smallStarCategory {
removeStar(secondBody.node!)
}
