I create SCNNode with .dae model.
let node = SCNNode()
let scene = SCNScene(named: "scene.scnassets/scene.dae")!
for child in scene.rootNode.childNodes
{
node.addChildNode(child)
}
Then add simbTransform and add node to the ar scene
var translation = matrix_identity_float4x4
translation.columns.3.z = -1
node.simdTransform = matrix_multiply(currentFrame.camera.transform, translation)
self.sceneView.scene.rootNode.addChildNode(node)
When I move camera node is attached to it. So i can't walk around node or walk up closer.
But when I do something like that, it work as I expected.
let node = SCNNode(geometry: SCNBox(width: 0.5, height: 0.5, length: 0.5, chamferRadius: 0))
var translation = matrix_identity_float4x4
translation.columns.3.z = -1
node.simdTransform = matrix_multiply(currentFrame.camera.transform, translation)
self.sceneView.scene.rootNode.addChildNode(node)
So how can I attach node with .dae model to specify position and not the camera.
In which method you are doing this code?
var translation = matrix_identity_float4x4
translation.columns.3.z = -1
node.simdTransform = matrix_multiply(currentFrame.camera.transform, translation)
self.sceneView.scene.rootNode.addChildNode(node)
If you do this in update method of AR session then it is logical because you change transform of the object every time camera moves.
Make sure you call this only once - during the scene setup.
I need to focus to certain node, for example a pyramid. Then apply distance to the camera, then move the camera based on user click. My approach is like this :
import SceneKit
class GameViewController: UIViewController {
let scene = SCNScene()
override func viewDidLoad() {
super.viewDidLoad()
let camera = SCNCamera()
camera.usesOrthographicProjection = true
camera.orthographicScale = 4
camera.zNear = 1
camera.zFar = 100
let cameraNode = SCNNode()
cameraNode.position = SCNVector3(x: 0, y: 0, z: 6)
cameraNode.camera = camera
let cameraOrbit = SCNNode()
cameraOrbit.name = "orbit"
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraOrbit)
let Py = SCNPyramid(width: 2, height: 3, length: 2)
Py.firstMaterial?.diffuse.contents = UIColor.purple()
let P = SCNNode(geometry: Py)
P.position = SCNVector3(x:0,y:0,z:2) //see the note
scene.rootNode.addChildNode(P)
/* N O T E :
the position of the pyramid must not be changed
as my intention is to rotate the camera
not the pyramid node
I repeat, I don't want to rotate the pyramid
*/
let scnView = self.view as! SCNView
scnView.scene = scene
scnView.allowsCameraControl = false
scnView.backgroundColor = UIColor.black()
// user rotates the camera by tapping
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
scnView.addGestureRecognizer(tapGesture)
}
//the function which does camera rotation :
func handleTap(_ gestureRecognize: UIGestureRecognizer) {
//I guess the solution is around here
//like modify the cameraOrbit.position ?
//or cameraNode.position ?
//tried both but doesn't work
//or I used them wrong
let cameraOrbit = scene.rootNode.childNode(withName: "orbit", recursively: true)!
SCNTransaction.begin()
SCNTransaction.animationDuration = 2
cameraOrbit.eulerAngles.z += Float(M_PI_2) //see below
SCNTransaction.commit()
/*
I realise that by performing rotation on the camera
(the camera position is unchanged) works for z rotation,
but this is not what I want. What I want is a solution,
which also works for eulerAngles.x and eulerAngles.y.
I used eulerAngles.z as example since it's easier to observe.
I guess the true solution involves moving the camera
with specific trajectory, not only rotation of "anchored" camera.
*/
}
//...
}
The result is :
What I want to achieve is to make the rotation relative to its centre :
My question is, how to adjust the pivot so I can achieve the rotation relative to the pyramid's centre?
Note : I don't want to rotate the pyramid.
I found the solution, but I can't explain why. Please comment if you can explain.
The camera orbit position must be set to match the object's location (in this case, the pyramid). So
cameraOrbit.position = P.position
Then here comes the mystery solution, add cameraOrbit.position.y by half of pi :
cameraOrbit.position.y += Float(M_PI_2)
//therefore we have the final cameraOrbit.position as (0, pi/2, 2)
Tested and works perfectly for all cameraOrbit.eulerAngles.
But I don't have a clue why it works. If pi/2 is coming from some projection thingy, then why it's tucked on y only? I mean, when I do any of the cameraOrbit.eulerAngles, I don't need to assign this pi/2 to either x or z.
Here it is the complete code
import SceneKit
class GameViewController: UIViewController {
let scene = SCNScene()
override func viewDidLoad() {
super.viewDidLoad()
let camera = SCNCamera()
camera.usesOrthographicProjection = true
camera.orthographicScale = 4
camera.zNear = 1
camera.zFar = 100
let cameraNode = SCNNode()
cameraNode.position = SCNVector3(x: 0, y: 0, z: 6)
cameraNode.camera = camera
let cameraOrbit = SCNNode()
cameraOrbit.name = "orbit"
cameraOrbit.addChildNode(cameraNode)
scene.rootNode.addChildNode(cameraOrbit)
let Py = SCNPyramid(width: 2, height: 3, length: 2)
Py.firstMaterial?.diffuse.contents = UIColor.purple()
let P = SCNNode(geometry: Py)
P.position = SCNVector3(x:0,y:0,z:2)
scene.rootNode.addChildNode(P)
// S O L U T I O N :
cameraOrbit.position = P.position
cameraOrbit.position.y += Float(M_PI_2)
//therefore we have the final cameraOrbit.position as (0, pi/2, 2)
let scnView = self.view as! SCNView
scnView.scene = scene
scnView.allowsCameraControl = false
scnView.backgroundColor = UIColor.black()
// user rotates the camera by tapping
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
scnView.addGestureRecognizer(tapGesture)
}
//the function which does camera rotation :
func handleTap(_ gestureRecognize: UIGestureRecognizer) {
//I was wrong, the solution is not here
let cameraOrbit = scene.rootNode.childNode(withName: "orbit", recursively: true)!
SCNTransaction.begin()
SCNTransaction.animationDuration = 2
cameraOrbit.eulerAngles.z += Float(M_PI_2) //works also for x and y
SCNTransaction.commit()
}
...
}
I am using SceneKit and allowing users to rotate what they're seeing inside a sphere by using a pan gesture. This is working fine - except, I'd like to have the sphere keep rotating slightly in the direction of the pan gesture, to feel a bit more reactive.
Here's my setup for the scene:
// Create scene
let scene = SCNScene()
sceneView.scene = scene
let panRecognizer = UIPanGestureRecognizer(target: self,
action: #selector(ViewController.handlePanGesture(_:)))
sceneView.addGestureRecognizer(panRecognizer)
//Create sphere
let sphere = SCNSphere(radius: 50.0)
// sphere setup
sphereNode = SCNNode(geometry: sphere)
sphereNode!.position = SCNVector3Make(0,0,0)
scene.rootNode.addChildNode(sphereNode!)
// Create camera
let camera = SCNCamera()
// camera setup
cameraNode = SCNNode()
cameraNode!.camera = camera
cameraNode!.position = SCNVector3Make(0, 0, 0)
cameraOrbit = SCNNode()
cameraOrbit!.addChildNode(cameraNode!)
scene.rootNode.addChildNode(cameraOrbit!)
let lookAtConstraint = SCNLookAtConstraint(target: sphereNode!)
lookAtConstraint.gimbalLockEnabled = true
cameraNode!.constraints = [lookAtConstraint]
sceneView.pointOfView = cameraNode
And here is how the pan gesture is currently handled (courtesy of SCNCamera limit arcball rotation):
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
if (sender.state == .Ended) {
lastWidthRatio = widthRatio
lastHeightRatio = heightRatio
}
I'm not sure where to begin in adding in a slight continued rotation motion. Maybe adding a physicsBody and applying force? Maybe animating the change in eulerAngles?
The way I've handled things like this before is to split the gesture handler into sections for the gesture state beginning, changing and ending. If the rotation is working for you all you need to do is add code to the bottom of your if (sender.state == .Ended) statement.
After lastHeightRatio = heightRatio you can find the velocity of the pan in the view using sender.velocityInView(sender.view!) and then find the horizontal component as before, then add an SCNAction to rotate the node with an EaseOut timing mode.
You'll likely need a multiplier to translate the velocity in the view (measured in points) to the angle you wish to rotate through (measured in radians). A velocity of 10 points, which is relatively small, would result in a very fast rotation.
Also you'll need to remove all actions from the node when the gesture begins again if you want a touch to stop the residual rotation.
Some sampel code would be:
if (sender.state == .Ended) {
lastWidthRatio = widthRatio
lastHeightRatio = heightRatio
// Find velocity
let velocity = sender.velocityInView(sender.view!)
// Create Action for whichever axis is the correct one to rotate about.
// The 0.00001 is just a factor to provide the rotation speed to pan
// speed ratio you'd like. Play with this number and the duration to get the result you want
let rotate = SCNAction.rotateByX(velocity.x * 0.00001, y: 0, z: 0, duration: 2.0)
// Run the action on the camera orbit node (if I understand your setup correctly)
cameraOrbit.runAction(rotate)
}
This should be enough to get you started.
Thanks for taking a look at this. I'm sure it is something very basic. I am a beginner.
I am trying to rotate a cube in in a SceneKit view with pan gestures. I have so far been successful in load this sample app onto my iPad and panning my finger on the y axis to rotate the cube on its x axis, or panning along the screens x-axis to rotate the cube along its y-axis.
Currently, I've noticed that whichever gesture recognizer is added last to the sceneView is the one that works. My question is how can I have the cube respond to either a x pan gesture then a y pan gesture or vice versa.
Here is the code I have written so far:
import UIKit
import SceneKit
class ViewController: UIViewController {
//geometry
var geometryNode: SCNNode = SCNNode()
//gestures
var currentYAngle: Float = 0.0
var currentXAngle: Float = 0.0
override func viewDidLoad() {
super.viewDidLoad()
sceneSetup()
}
func sceneSetup () {
//setup scene
let scene = SCNScene()
let sceneView = SCNView(frame: self.view.frame)
self.view.addSubview(sceneView)
//add camera
let camera = SCNCamera()
let cameraNode = SCNNode()
cameraNode.camera = camera
cameraNode.position = SCNVector3(x: 0.0, y: 0.0, z: 5.0)
//add light
let light = SCNLight()
light.type = SCNLightTypeOmni
let lightNode = SCNNode()
lightNode.light = light
lightNode.position = SCNVector3(x: 1.5, y: 1.5, z: 1.5)
//add cube
let cubeGeometry = SCNBox(width: 1.0, height: 1.0, length: 1.0, chamferRadius: 0.0)
let boxNode = SCNNode(geometry: cubeGeometry)
scene.rootNode.addChildNode(lightNode)
scene.rootNode.addChildNode(cameraNode)
scene.rootNode.addChildNode(boxNode)
geometryNode = boxNode
//add recognizers
let panXRecognizer = UIPanGestureRecognizer(target: self, action: "rotateXGesture:")
let panYRecognizer = UIPanGestureRecognizer(target: self, action: "rotateYGesture:")
sceneView.addGestureRecognizer(panXRecognizer)
sceneView.addGestureRecognizer(panYRecognizer)
sceneView.scene = scene
}
func rotateXGesture (sender: UIPanGestureRecognizer) {
let translation = sender.translationInView(sender.view)
var newXAngle = (Float)(translation.y)*(Float)(M_PI)/180.0
newXAngle += currentXAngle
geometryNode.transform = SCNMatrix4MakeRotation(newXAngle, 1, 0, 0)
if(sender.state == UIGestureRecognizerState.Ended) {
currentXAngle = newXAngle
}
}
func rotateYGesture (sender: UIPanGestureRecognizer) {
let translation = sender.translationInView(sender.view)
var newYAngle = (Float)(translation.x)*(Float)(M_PI)/180.0
newYAngle += currentYAngle
geometryNode.transform = SCNMatrix4MakeRotation(newYAngle, 0, 1, 0)
if(sender.state == UIGestureRecognizerState.Ended) {
currentYAngle = newYAngle
}
}
}
Combine your current two gestures into one. Here's the relevant portion of the code I'm using:
func panGesture(sender: UIPanGestureRecognizer) {
let translation = sender.translationInView(sender.view!)
var newAngleX = (Float)(translation.y)*(Float)(M_PI)/180.0
newAngleX += currentAngleX
var newAngleY = (Float)(translation.x)*(Float)(M_PI)/180.0
newAngleY += currentAngleY
baseNode.eulerAngles.x = newAngleX
baseNode.eulerAngles.y = newAngleY
if(sender.state == UIGestureRecognizerState.Ended) {
currentAngleX = newAngleX
currentAngleY = newAngleY
}
}
Here's a gesture for zooming as well:
func pinchGesture(sender: UIPinchGestureRecognizer) {
let zoom = sender.scale
var z = cameraNode.position.z * Float(1.0 / zoom)
z = fmaxf(zoomLimits.min, z)
z = fminf(zoomLimits.max, z)
cameraNode.position.z = z
}
Edit: I found a better way to rotate the model. In the panGesture code at the top, the x-axis pivots as you rotate about the y. This means if you rotate 180 about the y, rotation about the x is opposite your finger motion. The method also restricts motion to two degrees of freedom. The method linked to below, even though it doesn't directly affect the z-axis, somehow seems to allow three degrees of freedom. It also makes all vertical swipes rotate about the x in the logical direction.
How to rotate object in a scene with pan gesture - SceneKit
The way you set up your two gesture recognizers is identical, they will both fire for the same events (which is why the last one to be added predominates). There is no control within pan to specifically limit it to vertical or horizontal pans. Instead, consider analyzing the direction of the pan and then decide whether to rotate your gesture one way or the other, based upon which is greater.
I've got an SCNCamera at position(30,30,30) with a SCNLookAtConstraint on an object located at position(0,0,0). I'm trying to get the camera to rotate around the object on an imaginary sphere using A UIPanGestureRecognizer, while maintaining the radius between the camera and the object. I'm assuming I should use Quaternion projections but my math knowledge in this area is abysmal. My known variables are x & y translation + the radius I am trying to keep. I've written the project in Swift but an answer in Objective-C would be equally accepted (Hopefully using a standard Cocoa Touch Framework).
Where:
private var cubeView : SCNView!;
private var cubeScene : SCNScene!;
private var cameraNode : SCNNode!;
Here's my code for setting the scene:
// setup the SCNView
cubeView = SCNView(frame: CGRectMake(0, 0, self.width(), 175));
cubeView.autoenablesDefaultLighting = YES;
self.addSubview(cubeView);
// setup the scene
cubeScene = SCNScene();
cubeView.scene = cubeScene;
// setup the camera
let camera = SCNCamera();
camera.usesOrthographicProjection = YES;
camera.orthographicScale = 9;
camera.zNear = 0;
camera.zFar = 100;
cameraNode = SCNNode();
cameraNode.camera = camera;
cameraNode.position = SCNVector3Make(30, 30, 30)
cubeScene.rootNode.addChildNode(cameraNode)
// setup a target object
let box = SCNBox(width: 10, height: 10, length: 10, chamferRadius: 0);
let boxNode = SCNNode(geometry: box)
cubeScene.rootNode.addChildNode(boxNode)
// put a constraint on the camera
let targetNode = SCNLookAtConstraint(target: boxNode);
targetNode.gimbalLockEnabled = YES;
cameraNode.constraints = [targetNode];
// add a gesture recogniser
let gesture = UIPanGestureRecognizer(target: self, action: "panDetected:");
cubeView.addGestureRecognizer(gesture);
And here is the code for the gesture recogniser handling:
private var position: CGPoint!;
internal func panDetected(gesture:UIPanGestureRecognizer) {
switch(gesture.state) {
case UIGestureRecognizerState.Began:
position = CGPointZero;
case UIGestureRecognizerState.Changed:
let aPosition = gesture.translationInView(cubeView);
let delta = CGPointMake(aPosition.x-position.x, aPosition.y-position.y);
// ??? no idea...
position = aPosition;
default:
break
}
}
Thanks!
It might help to break down your issue into subproblems.
Setting the Scene
First, think about how to organize your scene to enable the kind of motion you want. You talk about moving the camera as if it's attached to an invisible sphere. Use that idea! Instead of trying to work out the math to set your cameraNode.position to some point on an imaginary sphere, just think about what you would do to move the camera if it were attached to a sphere. That is, just rotate the sphere.
If you wanted to rotate a sphere separately from the rest of your scene contents, you'd attach it to a separate node. Of course, you don't actually need to insert a sphere geometry into your scene. Just make a node whose position is concentric with the object you want your camera to orbit around, then attach the camera to a child node of that node. Then you can rotate that node to move the camera. Here's a quick demo of that, absent the scroll-event handling business:
let camera = SCNCamera()
camera.usesOrthographicProjection = true
camera.orthographicScale = 9
camera.zNear = 0
camera.zFar = 100
let cameraNode = SCNNode()
cameraNode.position = SCNVector3(x: 0, y: 0, z: 50)
cameraNode.camera = camera
let cameraOrbit = SCNNode()
cameraOrbit.addChildNode(cameraNode)
cubeScene.rootNode.addChildNode(cameraOrbit)
// rotate it (I've left out some animation code here to show just the rotation)
cameraOrbit.eulerAngles.x -= CGFloat(M_PI_4)
cameraOrbit.eulerAngles.y -= CGFloat(M_PI_4*3)
Here's what you see on the left, and a visualization of how it works on the right. The checkered sphere is cameraOrbit, and the green cone is cameraNode.
There's a couple of bonuses to this approach:
You don't have to set the initial camera position in Cartesian coordinates. Just place it at whatever distance you want along the z-axis. Since cameraNode is a child node of cameraOrbit, its own position stays constant -- the camera moves due to the rotation of cameraOrbit.
As long as you just want the camera pointed at the center of this imaginary sphere, you don't need a look-at constraint. The camera points in the -Z direction of the space it's in -- if you move it in the +Z direction, then rotate the parent node, the camera will always point at the center of the parent node (i.e. the center of rotation).
Handling Input
Now that you've got your scene architected for camera rotation, turning input events into rotation is pretty easy. Just how easy depends on what kind of control you're after:
Looking for arcball rotation? (It's great for direct manipulation, since you can feel like you're physically pushing a point on the 3D object.) There are some questions and answers about that already on SO -- most of them use GLKQuaternion. (UPDATE: GLK types are "sorta" available in Swift 1.2 / Xcode 6.3. Prior to those versions you can do your math in ObjC via a bridging header.)
For a simpler alternative, you can just map the x and y axes of your gesture to the yaw and pitch angles of your node. It's not as spiffy as arcball rotation, but it's pretty easy to implement -- all you need to do is work out a points-to-radians conversion that covers the amount of rotation you're after.
Either way, you can skip some of the gesture recognizer boilerplate and gain some handy interactive behaviors by using UIScrollView instead. (Not that there isn't usefulness to sticking with gesture recognizers -- this is just an easily implemented alternative.)
Drop one on top of your SCNView (without putting another view inside it to be scrolled) and set its contentSize to a multiple of its frame size... then during scrolling you can map the contentOffset to your eulerAngles:
func scrollViewDidScroll(scrollView: UIScrollView) {
let scrollWidthRatio = Float(scrollView.contentOffset.x / scrollView.frame.size.width)
let scrollHeightRatio = Float(scrollView.contentOffset.y / scrollView.frame.size.height)
cameraOrbit.eulerAngles.y = Float(-2 * M_PI) * scrollWidthRatio
cameraOrbit.eulerAngles.x = Float(-M_PI) * scrollHeightRatio
}
On the one hand, you have to do a bit more work for infinite scrolling if you want to spin endlessly in one or both directions. On the other, you get nice scroll-style inertia and bounce behaviors.
Hey I ran into the problem the other day and the solution I came up with is fairly simple but works well.
First I created my camera and added it to my scene like so:
// create and add a camera to the scene
cameraNode = [SCNNode node];
cameraNode.camera = [SCNCamera camera];
cameraNode.camera.automaticallyAdjustsZRange = YES;
[scene.rootNode addChildNode:cameraNode];
// place the camera
cameraNode.position = SCNVector3Make(0, 0, 0);
cameraNode.pivot = SCNMatrix4MakeTranslation(0, 0, -15); //the -15 here will become the rotation radius
Then I made a CGPoint slideVelocity class variable. And created a UIPanGestureRecognizer and a and in its callback I put the following:
-(void)handlePan:(UIPanGestureRecognizer *)gestureRecognize{
slideVelocity = [gestureRecognize velocityInView:self.view];
}
Then I have this method that is called every frame. Note that I use GLKit for quaternion math.
-(void)renderer:(id<SCNSceneRenderer>)aRenderer didRenderScene:(SCNScene *)scenie atTime:(NSTimeInterval)time {
//spin the camera according the the user's swipes
SCNQuaternion oldRot = cameraNode.rotation; //get the current rotation of the camera as a quaternion
GLKQuaternion rot = GLKQuaternionMakeWithAngleAndAxis(oldRot.w, oldRot.x, oldRot.y, oldRot.z); //make a GLKQuaternion from the SCNQuaternion
//The next function calls take these parameters: rotationAngle, xVector, yVector, zVector
//The angle is the size of the rotation (radians) and the vectors define the axis of rotation
GLKQuaternion rotX = GLKQuaternionMakeWithAngleAndAxis(-slideVelocity.x/viewSlideDivisor, 0, 1, 0); //For rotation when swiping with X we want to rotate *around* y axis, so if our vector is 0,1,0 that will be the y axis
GLKQuaternion rotY = GLKQuaternionMakeWithAngleAndAxis(-slideVelocity.y/viewSlideDivisor, 1, 0, 0); //For rotation by swiping with Y we want to rotate *around* the x axis. By the same logic, we use 1,0,0
GLKQuaternion netRot = GLKQuaternionMultiply(rotX, rotY); //To combine rotations, you multiply the quaternions. Here we are combining the x and y rotations
rot = GLKQuaternionMultiply(rot, netRot); //finally, we take the current rotation of the camera and rotate it by the new modified rotation.
//Then we have to separate the GLKQuaternion into components we can feed back into SceneKit
GLKVector3 axis = GLKQuaternionAxis(rot);
float angle = GLKQuaternionAngle(rot);
//finally we replace the current rotation of the camera with the updated rotation
cameraNode.rotation = SCNVector4Make(axis.x, axis.y, axis.z, angle);
//This specific implementation uses velocity. If you don't want that, use the rotation method above just replace slideVelocity.
//decrease the slider velocity
if (slideVelocity.x > -0.1 && slideVelocity.x < 0.1) {
slideVelocity.x = 0;
}
else {
slideVelocity.x += (slideVelocity.x > 0) ? -1 : 1;
}
if (slideVelocity.y > -0.1 && slideVelocity.y < 0.1) {
slideVelocity.y = 0;
}
else {
slideVelocity.y += (slideVelocity.y > 0) ? -1 : 1;
}
}
This code gives infinite Arcball rotation with velocity, which I believe is what you are looking for. Also, you don't need the SCNLookAtConstraint with this method. In fact, that will probably mess it up, so don't do that.
If you want to implement rickster's answer using a gesture recognizer, you have to save state information as you'll only be given a translation relative to the beginning of the gesture. I added two vars to my class
var lastWidthRatio: Float = 0
var lastHeightRatio: Float = 0
And implemented his rotate code as follows:
func handlePanGesture(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
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 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!)
var widthRatio = Float(translation.x) / Float(gestureRecognize.view!.frame.size.width) + lastWidthRatio
var heightRatio = Float(translation.y) / Float(gestureRecognize.view!.frame.size.height) + lastHeightRatio
if (numberOfTouches==fingersNeededToPan) {
// 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
}
}
override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
return .Landscape
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Release any cached data, images, etc that aren't in use.
}
}
There's no need to save the state anywhere but the node itself.
The code which uses some sort of width ratio behaves weirdly when you scroll back and forth repeatedly, and other code here looks overcomplicated.
I came up with a different (and I believe a better one) solution for gesture recognizers, based on #rickster's approach.
UIPanGestureRecognizer:
#objc func handlePan(recognizer: UIPanGestureRecognizer) {
let translation = recognizer.velocity(in: recognizer.view)
cameraOrbit.eulerAngles.y -= Float(translation.x/CGFloat(panModifier)).radians
cameraOrbit.eulerAngles.x -= Float(translation.y/CGFloat(panModifier)).radians
}
UIPinchGestureRecognizer:
#objc func handlePinch(recognizer: UIPinchGestureRecognizer) {
guard let camera = cameraOrbit.childNodes.first else {
return
}
let scale = recognizer.velocity
let z = camera.position.z - Float(scale)/Float(pinchModifier)
if z < MaxZoomOut, z > MaxZoomIn {
camera.position.z = z
}
}
I used velocity, as with translation when you slow down the touch it would still be the same event, causing the camera to whirl very fast, not what you'd expect.
panModifier and pinchModifier are simple constant numbers which you can use to adjust responsiveness. I found the optimal values to be 100 and 15 respectively.
MaxZoomOut and MaxZoomIn are constants as well and are exactly what they appear to be.
I also use an extension on Float to convert degrees to radians and vice-versa.
extension Float {
var radians: Float {
return self * .pi / 180
}
var degrees: Float {
return self * 180 / .pi
}
}
After trying to implement these solutions (in Objective-C) I realized that Scene Kit actually makes this a lot easier than doing all of this. SCNView has a sweet property called allowsCameraControl that puts in the appropriate gesture recognizers and moves the camera accordingly. The only problem is that it's not the arcball rotation that you're looking for, although that can be easily added by creating a child node, positioning it wherever you want, and giving it a SCNCamera. For example:
_sceneKitView.allowsCameraControl = YES; //_sceneKitView is a SCNView
//Setup Camera
SCNNode *cameraNode = [[SCNNode alloc]init];
cameraNode.position = SCNVector3Make(0, 0, 1);
SCNCamera *camera = [SCNCamera camera];
//setup your camera to fit your specific scene
camera.zNear = .1;
camera.zFar = 3;
cameraNode.camera = camera;
[_sceneKitView.scene.rootNode addChildNode:cameraNode];