適用於SceneKit IOS的​​平滑捏手勢

Question

我正在Arkit中為3D模型捏捏手勢，遇到一個問題，當我縮放模型時，它會滯后並且不能給我流暢的響應。 它工作正常，但我需要使其更平滑。

 @objc func scalePiece(gestureRecognizer : UIPinchGestureRecognizer) {   guard gestureRecognizer.view != nil else { return }

        if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {

            let scale = Float(gestureRecognizer.scale)

            let newscalex = scale / currentscalex
            let newscaley = scale / currentscaley
            let newscalez = scale / currentscalez

            self.drone.scale = SCNVector3(newscalex, newscaley, newscalez)

        }}

任何提示將不勝感激。

Answer 1

您可能在currentscale和計算出的newscale后面有一些邏輯，但是簡單的gestureRecognizer.scale提供平滑的縮放。 我認為您會遇到麻煩的縮放比例，因為直接設置了scale 。 使用SCNAction.scale

let action = SCNAction.scale(by: gestureRecognizer.scale, duration: 0.1)
lv.runAction(action)
gestureRecognizer.scale = 1

代替

self.drone.scale = SCNVector3(newscalex, newscaley, newscalez)

如果x，y，z的比例尺值不同，請使用customAction

let action = SCNAction.customAction(duration: 0.1) { (yourNode, elapsedTime) in
    let percentage = elapsedTime / 0.1
    let newscalex = scale / currentscalex * percentage
    let newscaley = scale / currentscaley * percentage
    let newscalez = scale / currentscalez * percentage
    yourNode.scale = SCNVector3(newscalex, newscaley, newscalez)
}

Answer 2

將所有三個軸的/都替換為*，並重置手勢識別器的比例。 換句話說，與標度相乘而不是除以標度。

為防止其按指數比例縮放，請在讀取后將其重新設置為1.0。 例如：

  if gestureRecognizer.state == .began || gestureRecognizer.state == .changed {
            let scale = Float(gestureRecognizer.scale)

            let newscalex = scale * self.drone.scale.x
            let newscaley = scale * self.drone.scale.y
            let newscalez = scale * self.drone.scale.z

            self.drone.scale = SCNVector3(newscalex, newscaley, newscalez)
            gestureRecognizer.scale = 1.0
   }

重置手勢Recognizer基本上是一種替代方法，用於將原始比例存儲在開始狀態，並在將其分配給當前對象之前將識別器的比例因子應用於該比例。 重要說明中的文檔中專門描述了這種情況： https : //developer.apple.com/documentation/uikit/touches_presses_and_gestures/handling_uikit_gestures/handling_pinch_gestures 。