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Swift SCNNode 3D立方体旋转到立方体上的一个点

scenekit swift ios

1

Deb S · 技术社区 · 8 年前

使用lookAtConstraint和in进行了尝试 func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval)

 cube = SCNNode(geometry: sphereGeometry)
        cube.position = SCNVector3Make(0.0, 0.0, 0.0)
        gamescn.rootNode.addChildNode(cube)

        cameraNode = SCNNode()
        cameraNode.camera = SCNCamera()
        cameraNode.position = SCNVector3(x: 0, y: 0, z: 40)
        gamescn.rootNode.addChildNode(cameraNode)

        lookAtConstraint

//        lookAtConstraint = SCNLookAtConstraint(target: cube)
//        lookAtConstraint.isGimbalLockEnabled = true
//        cameraNode.constraints = [lookAtConstraint]

还试图获得第一个中心点的偏差(初始[0,0,距中心的距离])-然后 cube.eulerAngles = deviation 在但立方体是随机旋转的。

1 回复 | 直到 8 年前

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Deb S 8 年前

我是如何做到这一点的-

建立了两个效用函数来获取asin&两点夹角的acos复合-

func angleBetweenVectorsCos(_ vectorB:SCNVector3) -> SCNFloat {
        let cosineAngle = (dot(vector: vectorB) / (magnitude * vectorB.magnitude))
        return SCNFloat(acos(cosineAngle))
}

func angleBetweenVectorsSin(_ vectorB:SCNVector3) -> SCNFloat {
        let cosineAngle = angleBetweenVectorsCos(vectorB)
        let sinangle = sqrt(1-cosineAngle*cosineAngle)
        return SCNFloat(acos(sinangle))
 }

func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval)

func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {
        if time > rotationTimer{


            let angleCos = lastposition.angleBetweenVectorsCos(movingTarget.position)
            let angleSin = lastposition.angleBetweenVectorsSin(movingTarget.position)
            SCNTransaction.begin()
            SCNTransaction.animationDuration = 0.5
            xDegree += angleSin
            yDegree += angleCos
            zDegree += 0

            if vMove {
                cube.eulerAngles.x =  xDegree
            }
            if hMove {
                cube.eulerAngles.y =  -yDegree
            }


            SCNTransaction.commit()
            lastposition = movingTarget.position
            .......    
            rotationTimer = time + 0.2
        }

    }

如何获得vMove(垂直移动)和hMove(水平移动)-通过检测到距离原点的距离,仅计算移动对象所在的曲面。

我为此做了完整的github回购。 See this and suggest some improvements