Swift SceneKit node scroll - swift

I implemented my own method of scrolling the sphere, but when scrolling, it feels like lags
when I use the standard scrolling method (allowsCameraControl = true), when the sphere is jerked sharply to the side (like a swipe), the sphere will scroll for some time before stopping, in my case not. How can I do the same?
// Set scene settings
sceneView.scene = scene
cameraOrbit = SCNNode()
cameraNode = SCNNode()
cameraNode.name = "camera"
camera = SCNCamera()
// camera stuff
camera.usesOrthographicProjection = true
camera.orthographicScale = 5
camera.zNear = 1
camera.zFar = 100
// initially position is far away as we will animate moving into the globe
cameraNode.position = SCNVector3(x: 0, y: 0, z: 50)
cameraNode.camera = camera
cameraOrbit = SCNNode()
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraNode)
// Material
let blueMaterial = SCNMaterial()
blueMaterial.diffuse.contents = UIImage(named: "earth2")
blueMaterial.shininess = 0.05
blueMaterial.multiply.contents = UIColor(displayP3Red: 0.7, green: 0.7, blue: 0.7, alpha: 1.0)
let sphere = SCNSphere(radius: 2)
sphere.segmentCount = 300
sphere.firstMaterial?.diffuse.contents = UIColor.red
earthNode = SCNNode(geometry: sphere)
earthNode.name = "sphere"
earthNode.geometry?.materials = [blueMaterial]
scene.rootNode.addChildNode(earthNode)
earthNode.rotation = SCNVector4(0, 1, 0, 0)
sceneView.allowsCameraControl = false
sceneView.backgroundColor = UIColor.clear
sceneView.cameraControlConfiguration.allowsTranslation = true
sceneView.cameraControlConfiguration.rotationSensitivity = 0.4
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handlePan(_:)))
sceneView.addGestureRecognizer(panGesture)
#objc func handlePan(_ gestureRecognize: UIPanGestureRecognizer) {
if gestureRecognize.numberOfTouches == 1 { //leftRightAttenuation = 5.0
if (gestureRecognize.state == UIGestureRecognizer.State.changed) {
let scrollWidthRatio = Float(gestureRecognize.velocity(in: gestureRecognize.view!).x) / (leftRightAttenuation * 10000)
let scrollHeightRatio = Float(gestureRecognize.velocity(in: gestureRecognize.view!).y) / (leftRightAttenuation * 10000)
cameraOrbit.eulerAngles.y += Float(-2 * Double.pi) * scrollWidthRatio
cameraOrbit.eulerAngles.x += Float(-Double.pi) * scrollHeightRatio
}
}
}
Video with standart scroll (allowsCameraControl = true)
https://youtu.be/0BL0mY26ZkY
Video with my own scroll (allowsCameraControl = false)
https://youtu.be/ZwRgJMDZpmA

Have a look at this:
https://github.com/gadsden/SceneKit-Quaternion-Rotations
Contains 3 different methods of how to rotate objects.

Related

SCNNode rotation around a generic axis with animation

I need to rotate the gray bar around the red dot (see picture below).
I managed to do that translating the center point of the bar, rotating the bar and then translating the bar back to the original position.
Down here my code:
struct TestView2: View {
var scene: SCNScene
var arm: SCNNode
var length = 16.0
var with = 1.0
init() {
scene = SCNScene()
scene.setAttribute(400000, forKey: SCNScene.Attribute.endTime.rawValue)
let rootNode = scene.rootNode
let armShape = SCNBox(width: with, height: 0.5, length: length, chamferRadius: 0)
armShape.firstMaterial?.diffuse.contents = NSColor.gray
arm = SCNNode()
arm.geometry = armShape
arm.position = SCNVector3(0, 0, 0)
rootNode.addChildNode(arm)
let axisShape = SCNCylinder(radius: with/2, height: 0.51)
axisShape.firstMaterial?.diffuse.contents = NSColor.red
let axis = SCNNode()
axis.geometry = axisShape
axis.position = SCNVector3(0, 0, length/2-with/2)
rootNode.addChildNode(axis)
// Camera
let camera = SCNNode()
camera.camera = SCNCamera()
camera.camera?.usesOrthographicProjection = true
camera.camera?.orthographicScale = 15
camera.camera?.zNear = 0
camera.camera?.zFar = 100
camera.position = SCNVector3(0, 0, 50)
let cameraOrbit = SCNNode()
cameraOrbit.addChildNode(camera)
rootNode.addChildNode(cameraOrbit)
var eulerAngles = cameraOrbit.eulerAngles
eulerAngles.x = CGFloat(Float.pi / 2.0)
eulerAngles.y = 0
eulerAngles.z = 0
cameraOrbit.eulerAngles = eulerAngles
}
var body: some View {
VStack {
SceneView(scene: scene, options: [.allowsCameraControl, .autoenablesDefaultLighting])
Button("Rotate") {
let currentTransform = arm.transform
let translationTransform = SCNMatrix4MakeTranslation(0, 0, length/2-with/2)
let rotationTrasform = SCNMatrix4MakeRotation(90 * .pi / 180.0, 0, 1, 0)
let backTranslationTransform = SCNMatrix4MakeTranslation(0, 0, -(length/2-with/2))
let newTransform = SCNMatrix4Mult(backTranslationTransform,
SCNMatrix4Mult(rotationTrasform,
SCNMatrix4Mult(translationTransform, currentTransform)))
arm.transform = newTransform
}
}
}
}
The bar rotate as expected. I then added an animation:
...
let animation = CABasicAnimation(keyPath: "transform")
let currentTransform = arm.transform
let translationTransform = SCNMatrix4MakeTranslation(0, 0, length/2-with/2)
let rotationTrasform = SCNMatrix4MakeRotation(90 * .pi / 180.0, 0, 1, 0)
let backTranslationTransform = SCNMatrix4MakeTranslation(0, 0, -(length/2-with/2))
let newTransform = SCNMatrix4Mult(backTranslationTransform,
SCNMatrix4Mult(rotationTrasform,
SCNMatrix4Mult(translationTransform, currentTransform)))
animation.fromValue = currentTransform
animation.toValue = newTransform
animation.duration = 1.0
arm.addAnimation(animation, forKey: nil)
arm.transform = newTransform
...
The result is very clumsy though because the translations before and after the rotation are visible:
Since I am new to SceneKit, I think my approach to rotate the bar is completely wrong.
How can I improve the code to have both the rotation and animation at the same time?

How to change SCNView pivot point

Question
How does the SceneView/camera work out around which point to rotate, and how do I force the scene to rotate around the red sphere (-2, 0, 0)?
Demo
In this example SceneView I have placed
a camera at (-2, 0, 5)
a red sphere at (-2, 0, 0)
a blue sphere at (-1, 0, 0)
a white sphere at (0, 0, 0)
So the camera is in the same position along the x-axis as the red sphere
In the image you see the scene rotates around the blue sphere.
Playground example
Here is a working playground to produce the above example
import UIKit
import SceneKit
import PlaygroundSupport
var scene = SCNScene()
var sceneView: SCNView = {
let s = SCNView(
frame: CGRect(x: 0, y: 0, width: 600, height: 600)
)
s.scene = scene
s.backgroundColor = UIColor.black
s.allowsCameraControl = true
return s
}()
PlaygroundPage.current.liveView = sceneView
let redXPosition: simd_float1 = -2.0
let blueXPosition: simd_float1 = -1.0
let originXPosition: simd_float1 = 0.0
// MARK: Scene Nodes
let cameraNode: SCNNode = {
let n = SCNNode()
n.camera = SCNCamera()
n.camera?.contrast = 0.0
n.camera?.wantsHDR = false
return n
}()
cameraNode.simdPosition = simd_float3(redXPosition, 0, 5)
scene.rootNode.addChildNode(cameraNode)
let ambientLightNode: SCNNode = {
let n = SCNNode()
n.light = SCNLight()
n.light!.type = SCNLight.LightType.ambient
n.light!.color = UIColor(white: 0.75, alpha: 1.0)
return n
}()
ambientLightNode.simdPosition = simd_float3(0,5,0)
scene.rootNode.addChildNode(ambientLightNode)
// MARK: Spheres
// MARK: Origin - White
let originNode: SCNNode = {
let sphere = SCNSphere(radius: 0.5)
let node = SCNNode(geometry: sphere)
let mat = SCNMaterial()
mat.diffuse.contents = UIColor.white
sphere.materials = [mat]
return node
}()
// MARK: Red
let redNode: SCNNode = {
let sphere = SCNSphere(radius: 0.3)
let node = SCNNode(geometry: sphere)
let mat = SCNMaterial()
mat.diffuse.contents = UIColor.red
sphere.materials = [mat]
return node
}()
// MARK: Blue
let blueNode: SCNNode = {
let sphere = SCNSphere(radius: 0.3)
let node = SCNNode(geometry: sphere)
let mat = SCNMaterial()
mat.diffuse.contents = UIColor.blue
sphere.materials = [mat]
return node
}()
// MARK: Place nodes in scene
originNode.simdPosition = simd_float3(originXPosition,0,0)
redNode.simdPosition = simd_float3(redXPosition,0,0)
blueNode.simdPosition = simd_float3(blueXPosition,0,0)
scene.rootNode.addChildNode(originNode)
scene.rootNode.addChildNode(redNode)
scene.rootNode.addChildNode(blueNode)

ARKit –Drop a shadow of 3D object on the plane surface

This is the function that I use to display object on the plane surface.
private func loadScene(path: String) -> SCNNode {
let spotLight = SCNLight()
spotLight.type = SCNLight.LightType.probe
spotLight.spotInnerAngle = 30.0
spotLight.spotOuterAngle = 80.0
spotLight.castsShadow = true
let result = SCNNode()
result.light = spotLight
result.position = SCNVector3(-10.0, 20.0, 10.5)
result.addChildNode(result)
let scene = SCNScene(named: path)!
for node in scene.rootNode.childNodes {
result.addChildNode(node)
}
return result
}
I want to display shadow on the plane surface like this image.
When I set spotlight type like below
spotLight.type = SCNLight.LightType.directional
It shows the object itself with light/dark shadow and does not drop the shadow on the surface.
Can someone please guide me how can I achieve the output as shown in the image?
// To Add Shadow on 3D Model Just Copy Paste this code and it will appear a shadow of 3D Model on Ground
let flourPlane = SCNFloor()
let groundPlane = SCNNode()
let groundMaterial = SCNMaterial()
groundMaterial.lightingModel = .constant
groundMaterial.writesToDepthBuffer = true
groundMaterial.colorBufferWriteMask = []
groundMaterial.isDoubleSided = true
flourPlane.materials = [groundMaterial]
groundPlane.geometry = flourPlane
//
mainNode.addChildNode(groundPlane)
// Create a ambient light
let ambientLight = SCNNode()
ambientLight.light = SCNLight()
ambientLight.light?.shadowMode = .deferred
ambientLight.light?.color = UIColor.white
ambientLight.light?.type = SCNLight.LightType.ambient
ambientLight.position = SCNVector3(x: 0,y: 5,z: 0)
// Create a directional light node with shadow
let myNode = SCNNode()
myNode.light = SCNLight()
myNode.light?.type = SCNLight.LightType.directional
myNode.light?.color = UIColor.white
myNode.light?.castsShadow = true
myNode.light?.automaticallyAdjustsShadowProjection = true
myNode.light?.shadowSampleCount = 64
myNode.light?.shadowRadius = 16
myNode.light?.shadowMode = .deferred
myNode.light?.shadowMapSize = CGSize(width: 2048, height: 2048)
myNode.light?.shadowColor = UIColor.black.withAlphaComponent(0.75)
myNode.position = SCNVector3(x: 0,y: 5,z: 0)
myNode.eulerAngles = SCNVector3(-Float.pi / 2, 0, 0)
// Add the lights to the container
mainNode.addChildNode(ambientLight)
mainNode.addChildNode(myNode)
// End
This edited version of the answer worked for me. I used material with shadowOnly model.
let flourPlane = SCNFloor()
let groundPlane = SCNNode()
let groundMaterial = SCNMaterial()
groundMaterial.lightingModel = .shadowOnly
flourPlane.materials = [groundMaterial]
groundPlane.geometry = flourPlane
//
node.addChildNode(groundPlane)
// Create a ambient light
let ambientLight = SCNNode()
ambientLight.light = SCNLight()
ambientLight.light?.shadowMode = .deferred
ambientLight.light?.color = UIColor.white
ambientLight.light?.type = SCNLight.LightType.ambient
ambientLight.position = SCNVector3(x: 0,y: 5,z: 0)
// Create a directional light node with shadow
let myNode = SCNNode()
myNode.light = SCNLight()
myNode.light?.type = SCNLight.LightType.directional
myNode.light?.color = UIColor.white
myNode.light?.castsShadow = true
myNode.light?.automaticallyAdjustsShadowProjection = true
myNode.light?.shadowSampleCount = 64
myNode.light?.shadowRadius = 16
myNode.light?.shadowMode = .deferred
myNode.light?.shadowMapSize = CGSize(width: 2048, height: 2048)
myNode.light?.shadowColor = UIColor.black.withAlphaComponent(0.75)
myNode.position = SCNVector3(x: 0,y: 1,z: -3)
myNode.eulerAngles = SCNVector3(-Float.pi / 2, 0, 0)
// Add the lights to the container
node.addChildNode(ambientLight)
node.addChildNode(myNode)

How do I handle collision detection in Scenekit with Swift?

I have been trying to set up a simple Scenekit scene with some physics so I could learn about how SCNPhysicsContactDelegate, categoryBitMask, collisionBitMask and the physicsWorld func work. Not sure if I need to set up a contactTestBitMask as well.
Learning about contact detection sent me down a long path of bitwise operators and the concept of bit masking. Adding in binary is fun! However, this is all still very foggy and I am trying to cobble together several tutorials I've found in both SpriteKit and SceneKit. This is the most comprehensive but it is in Obj-C and I don't understand it how to translate to Swift.
Here is what I have created. Any insights would be much appreciated. Can you see what I have set up incorrectly? I would like to have a simple Print statement occur when the red rolling ball hits the blue target. The floor, ramp and target are .static, while the rolling ball is .dynamic.
import UIKit
import SceneKit
class ViewController: UIViewController, SCNPhysicsContactDelegate {
//category bit masks for ball node and target node
// ball = 0001 -> 1 and target = 0010 ->2
let collisionRollingBall: Int = 1 << 0
let collsionTarget: Int = 1 << 1
//declare variables
var sceneView: SCNView!
var cameraNode: SCNNode!
var groundNode: SCNNode!
var lightNode: SCNNode!
var rampNode: SCNNode!
var rollingBallNode: SCNNode!
var targetNode: SCNNode!
override func viewDidLoad() {
super.viewDidLoad()
//set up sceneview and scene. Define the physicsworld contact delegate as self
sceneView = SCNView(frame: self.view.frame)
sceneView.scene = SCNScene()
sceneView.scene!.physicsWorld.contactDelegate = self
self.view.addSubview(sceneView)
//add floor
let groundGeometry = SCNFloor()
groundGeometry.reflectivity = 0
let groundMaterial = SCNMaterial()
groundMaterial.diffuse.contents = UIColor.greenColor()
groundGeometry.materials = [groundMaterial]
groundNode = SCNNode(geometry: groundGeometry)
//add ramp
let rampGeometry = SCNBox(width: 4, height: 1, length: 18, chamferRadius: 0)
rampNode = SCNNode(geometry: rampGeometry)
rampNode.position = SCNVector3(x: 0, y: 2.0, z: 1.0)
rampNode.rotation = SCNVector4(1, 0, 0, 0.26)
//add rolling ball
let rollingBallGeometry = SCNSphere(radius: 0.5)
let sphereMaterial = SCNMaterial()
sphereMaterial.diffuse.contents = UIColor.redColor()
rollingBallGeometry.materials = [sphereMaterial]
rollingBallNode = SCNNode(geometry: rollingBallGeometry)
rollingBallNode.position = SCNVector3(0, 6, -6)
//add target box
let targetBoxGeometry = SCNBox(width: 4, height: 1, length: 4, chamferRadius: 0)
let targetMaterial = SCNMaterial()
targetMaterial.diffuse.contents = UIColor.blueColor()
targetBoxGeometry.materials = [targetMaterial]
targetNode = SCNNode(geometry: targetBoxGeometry)
targetNode.position = SCNVector3(x: 0, y: 0.5, z: 11.5)
targetNode.rotation = SCNVector4(-1,0,0,0.592)
//add a camera
let camera = SCNCamera()
self.cameraNode = SCNNode()
self.cameraNode.camera = camera
self.cameraNode.position = SCNVector3(x: 13, y: 5, z: 12)
let constraint = SCNLookAtConstraint(target: rampNode)
self.cameraNode.constraints = [constraint]
constraint.gimbalLockEnabled = true
//add a light
let spotLight = SCNLight()
spotLight.type = SCNLightTypeSpot
spotLight.castsShadow = true
spotLight.spotInnerAngle = 70.0
spotLight.spotOuterAngle = 90.0
spotLight.zFar = 500
lightNode = SCNNode()
lightNode.light = spotLight
lightNode.position = SCNVector3(x: 0, y: 25, z: 25)
lightNode.constraints = [constraint]
//define physcis bodies
let groundShape = SCNPhysicsShape(geometry: groundGeometry, options: nil)
let groundBody = SCNPhysicsBody(type: .Static, shape: groundShape)
groundNode.physicsBody = groundBody
let rampShape = SCNPhysicsShape(geometry: rampGeometry, options: nil)
let rampBody = SCNPhysicsBody(type: .Static, shape: rampShape)
rampNode.physicsBody = rampBody
let sphereShape = SCNPhysicsShape(geometry: rollingBallGeometry, options: nil)
let sphereBody = SCNPhysicsBody(type: .Dynamic, shape: sphereShape)
rollingBallNode.physicsBody?.categoryBitMask = collisionRollingBall
rollingBallNode.physicsBody?.collisionBitMask = collsionTarget
rollingBallNode.physicsBody = sphereBody
let targetShape = SCNPhysicsShape(geometry: targetBoxGeometry, options: nil)
let targetBody = SCNPhysicsBody(type: .Static, shape: targetShape)
targetNode.physicsBody?.categoryBitMask = collsionTarget
targetNode.physicsBody?.collisionBitMask = collisionRollingBall
targetNode.physicsBody = targetBody
//add nodes to view
sceneView.scene?.rootNode.addChildNode(groundNode)
sceneView.scene?.rootNode.addChildNode(rampNode)
sceneView.scene?.rootNode.addChildNode(rollingBallNode)
sceneView.scene?.rootNode.addChildNode(targetNode)
sceneView.scene?.rootNode.addChildNode(self.cameraNode)
sceneView.scene?.rootNode.addChildNode(lightNode)
}
func physicsWorld(world: SCNPhysicsWorld, didBeginContact contact: SCNPhysicsContact) {
print("contact")
// let contactMask = contact.nodeA.categoryBitMask |
//contact.nodeB.categoryBitMask
//if contactMask == collsionTarget | collisionRollingBall {
// print("The ball hit the target")
// }
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
I think you're having to reset the "catagoryBitMask" value in the delegate function because you're trying to set the "catagoryBitMask" and "collisionBitMask" values when the physicsBody is still nil.
rollingBallNode.physicsBody?.categoryBitMask = collisionRollingBall
rollingBallNode.physicsBody?.collisionBitMask = collsionTarget
rollingBallNode.physicsBody = sphereBody
Try putting that 3rd line 1st.

SCNCamera limit arcball rotation

I have a scene setup with SCNCamera that rotates around an object.
What would be the best way to limit the extents of rotation the camera can achieve around the object?
Example: instead of being able to rotate around a whole sphere, how would I limit rotation to a single hemisphere?
My first attempt was to see if there was any clamps for .allowsCameraControl. Could not find anything.
I then tried adapting c# Unity : mouse orbit script, no luck.
Some pointers on how to approach or solve this would great.
Boilerplate Arcball thanks to this answer.
var lastWidthRatio: Float = 0
var lastHeightRatio: Float = 0
let camera = SCNCamera()
let cameraNode = SCNNode()
let cameraOrbit = SCNNode()
override func viewDidLoad() {
super.viewDidLoad()
// create a new scene
let scene = SCNScene(named: "art.scnassets/ship.scn")!
// create and add a camera to the scene
camera.usesOrthographicProjection = true
camera.orthographicScale = 9
camera.zNear = 0
camera.zFar = 100
cameraNode.position = SCNVector3(x: 0, y: 0, z: 50)
cameraNode.camera = camera
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraOrbit)
// retrieve the ship node
let ship = scene.rootNode.childNodeWithName("ship", recursively: true)!
// retrieve the SCNView
let scnView = self.view as! SCNView
// set the scene to the view
scnView.scene = scene
// add a tap gesture recognizer
let gesture = UIPanGestureRecognizer(target: self, action: "panDetected:");
scnView.addGestureRecognizer(gesture);
}
func panDetected(sender: UIPanGestureRecognizer) {
let translation = sender.translationInView(sender.view!)
let widthRatio = Float(translation.x) / Float(sender.view!.frame.size.width) + lastWidthRatio
let heightRatio = Float(translation.y) / Float(sender.view!.frame.size.height) + lastHeightRatio
self.cameraOrbit.eulerAngles.y = Float(-2 * M_PI) * widthRatio
self.cameraOrbit.eulerAngles.x = Float(-M_PI) * heightRatio
print(Float(-2 * M_PI) * widthRatio)
if (sender.state == .Ended) {
lastWidthRatio = widthRatio % 1
lastHeightRatio = heightRatio % 1
}
}
Maybe this could be useful for readers.
class GameViewController: UIViewController {
var cameraOrbit = SCNNode()
let cameraNode = SCNNode()
let camera = SCNCamera()
//HANDLE PAN CAMERA
var lastWidthRatio: Float = 0
var lastHeightRatio: Float = 0.2
var WidthRatio: Float = 0
var HeightRatio: Float = 0.2
var fingersNeededToPan = 1
var maxWidthRatioRight: Float = 0.2
var maxWidthRatioLeft: Float = -0.2
var maxHeightRatioXDown: Float = 0.02
var maxHeightRatioXUp: Float = 0.4
//HANDLE PINCH CAMERA
var pinchAttenuation = 20.0 //1.0: very fast ---- 100.0 very slow
var lastFingersNumber = 0
override func viewDidLoad() {
super.viewDidLoad()
// create a new scene
let scene = SCNScene(named: "art.scnassets/ship.scn")!
// create and add a light to the scene
let lightNode = SCNNode()
lightNode.light = SCNLight()
lightNode.light!.type = SCNLightTypeOmni
lightNode.position = SCNVector3(x: 0, y: 10, z: 10)
scene.rootNode.addChildNode(lightNode)
// create and add an ambient light to the scene
let ambientLightNode = SCNNode()
ambientLightNode.light = SCNLight()
ambientLightNode.light!.type = SCNLightTypeAmbient
ambientLightNode.light!.color = UIColor.darkGrayColor()
scene.rootNode.addChildNode(ambientLightNode)
//Create a camera like Rickster said
camera.usesOrthographicProjection = true
camera.orthographicScale = 9
camera.zNear = 1
camera.zFar = 100
cameraNode.position = SCNVector3(x: 0, y: 0, z: 50)
cameraNode.camera = camera
cameraOrbit = SCNNode()
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraOrbit)
//initial camera setup
self.cameraOrbit.eulerAngles.y = Float(-2 * M_PI) * lastWidthRatio
self.cameraOrbit.eulerAngles.x = Float(-M_PI) * lastHeightRatio
// retrieve the SCNView
let scnView = self.view as! SCNView
// set the scene to the view
scnView.scene = scene
//allows the user to manipulate the camera
scnView.allowsCameraControl = false //not needed
// add a tap gesture recognizer
let panGesture = UIPanGestureRecognizer(target: self, action: "handlePan:")
scnView.addGestureRecognizer(panGesture)
// add a pinch gesture recognizer
let pinchGesture = UIPinchGestureRecognizer(target: self, action: "handlePinch:")
scnView.addGestureRecognizer(pinchGesture)
}
func handlePan(gestureRecognize: UIPanGestureRecognizer) {
let numberOfTouches = gestureRecognize.numberOfTouches()
let translation = gestureRecognize.translationInView(gestureRecognize.view!)
if (numberOfTouches==fingersNeededToPan) {
widthRatio = Float(translation.x) / Float(gestureRecognize.view!.frame.size.width) + lastWidthRatio
heightRatio = Float(translation.y) / Float(gestureRecognize.view!.frame.size.height) + lastHeightRatio
// HEIGHT constraints
if (heightRatio >= maxHeightRatioXUp ) {
heightRatio = maxHeightRatioXUp
}
if (heightRatio <= maxHeightRatioXDown ) {
heightRatio = maxHeightRatioXDown
}
// WIDTH constraints
if(widthRatio >= maxWidthRatioRight) {
widthRatio = maxWidthRatioRight
}
if(widthRatio <= maxWidthRatioLeft) {
widthRatio = maxWidthRatioLeft
}
self.cameraOrbit.eulerAngles.y = Float(-2 * M_PI) * widthRatio
self.cameraOrbit.eulerAngles.x = Float(-M_PI) * heightRatio
print("Height: \(round(heightRatio*100))")
print("Width: \(round(widthRatio*100))")
//for final check on fingers number
lastFingersNumber = fingersNeededToPan
}
lastFingersNumber = (numberOfTouches>0 ? numberOfTouches : lastFingersNumber)
if (gestureRecognize.state == .Ended && lastFingersNumber==fingersNeededToPan) {
lastWidthRatio = widthRatio
lastHeightRatio = heightRatio
print("Pan with \(lastFingersNumber) finger\(lastFingersNumber>1 ? "s" : "")")
}
}
func handlePinch(gestureRecognize: UIPinchGestureRecognizer) {
let pinchVelocity = Double.init(gestureRecognize.velocity)
//print("PinchVelocity \(pinchVelocity)")
camera.orthographicScale -= (pinchVelocity/pinchAttenuation)
if camera.orthographicScale <= 0.5 {
camera.orthographicScale = 0.5
}
if camera.orthographicScale >= 10.0 {
camera.orthographicScale = 10.0
}
}
It looks like you're almost there, using just the #Rickster code from
the answer you cited.
The change you could make would be in these lines:
self.cameraOrbit.eulerAngles.y = Float(-2 * M_PI) * widthRatio
self.cameraOrbit.eulerAngles.x = Float(-M_PI) * heightRatio
which implicitly allow pitch and yaw to cover the entire
sphere. That's where you can do your limiting. For instance,
instead of allowing the pitch (eulerAngles.x) to vary from 0
to -π, you could do
self.cameraOrbit.eulerAngles.x = Float(-M_PI_2) + Float(-M_PI_2) * heightRatio
to vary smoothly between -π/2 and -π, using full screen
vertical scrolling to cover that range. Or you could put
hard min/max limits/checks in those two lines to constrain
to a particular area of the globe.
(Edit to address the inertia comment)
For rotational damping, or inertia, I'd approach it by using the built in SceneKit Physics, and perhaps put the camera on an invisible (no geometry) SCNNode. That camera node becomes a gimbal, similar to the approach taken in this project: An interactive seven-foot globe created entirely in RubyMotion and SceneKit.
The virtual gimbal then gets an SCNPhysicsBody (you add that, it doesn't come with one by default) with some damping. Or perhaps you put the physics on your central object, and give that object some angularDamping.