I'm trying to figure out how to programmatically assign a material to some object (SCNNode) in my scene for ARKit (XCode 9 / Swift 4). I'm trying to programmatically do this because I want the same shaped object to be rendered with way too many variants (or user-generated images) to be able to do it via the menu assignment in a scene. The object just a cube - for now, I'm just trying to get one side to display this material pulled from the Assets folder.
This is the current code that I've tried referencing prior Stack posts, but the object is just remaining white.
let material = SCNMaterial()
material.diffuse.contents = UIImage(named: "texture.jpg")
let nodeObject = self.lastUsedObject?.childNode(withName: "box", recursively: true)
// I believed this lets me grab the last thing I rendered in an ARKit scene - please
// correct me if I'm wrong. My object is also labeled "box".
nodeObject?.geometry?.materials
nodeObject?.geometry?.materials[0] = material // I wanted to grab the first face of the box
Thank you so much in advance! I've been fiddling with this for a while but I can't seem to get the grasp of programmatic methods for 3D objects / Scenes in Swift.
Overall, I was setting the materials of an object like this and it was working (to only grab one face of the box
var imageMaterial = SCNMaterial()
imageMaterial.isDoubleSided = false
imageMaterial.diffuse.contents = UIImage(named: "myImage")
var cube: SCNGeometry? = SCNBox(width: 1.0, height: 1.0, length: 1, chamferRadius: 0)
var node = SCNNode(geometry: cube)
node.geometry?.materials = [imageMaterial]
So it could possibly be that you haven't been able to grab the object, as stated in the comments.
Related
I'm building an app similar to Polycam, 3D Scanner App, Scaniverse, etc. I visualize a mesh for scanned regions and export it into different formats. I would like to show the user what regions are scanned, and what not. To do so, I need to differentiate between them.
My idea is to build something like Polycam does..
< Polycam blue background for unscanned regions >
I tried changing the background content property of the scene, but it causes the whole camera view to be replaced by the color.
arSceneView.scene.background.contents = UIColor.black
I'm using ARSCNView and setting up plane detection as follows:
private func setupPlaneDetection() {
let configuration = ARWorldTrackingConfiguration()
configuration.planeDetection = [.horizontal, .vertical]
configuration.sceneReconstruction = .meshWithClassification
configuration.frameSemantics = .smoothedSceneDepth
arSceneView.session.run(configuration)
arSceneView.session.delegate = self
// arSceneView.scene.background.contents = UIColor.black
arSceneView.delegate = self
UIApplication.shared.isIdleTimerDisabled = true
arSceneView.showsStatistics = true
}
Thanks in advance for any help you can provide!
I’ve done this before by adding a sphere to the scene with a two-sided material (slightly transparent) and with a radius large enough that the camera and the scanned surface will always be inside of it. Here’s an example of how to do that:
let backgroundSphereNode = SCNNode()
backgroundSphereNode.geometry = SCNSphere(radius: 500)
let material = SCNMaterial()
material.isDoubleSided = true
material?.diffuse.contents = UIColor(white: 0, alpha: 0.9)
backgroundSphereNode.geometry?.materials = [material]
Note that I’m using a black color - you can obviously change this to whatever you need, but keep the alpha channel slightly transparent. And tweak the radius of the sphere so it works for your scene.
I put some objects in AR space using ARKit and SceneKit. That works well. Now I'd like to add an additional camera (SCNCamera) that is placed elsewhere in the scene attached and positioned by a common SCNNode. It is oriented to show me the current scene from an other (fixed) perspective.
Now I'd like to show this additional SCNCamera feed on i.Ex. a SCNPlane (as the diffuse first material) - Like a TV screen. Of course I am aware that it will only display the SceneKit content which stays in the camera focus and not rest of the ARKit image (which is only possible by the main camera of course). A simple colored background then would be fine.
I have seen tutorials that describes, how to play a video file on a virtual display in ARSpace, but I need a realtime camera feed from my own current scene.
I defined this objects:
let camera = SCNCamera()
let cameraNode = SCNNode()
Then in viewDidLoad I do this:
camera.usesOrthographicProjection = true
camera.orthographicScale = 9
camera.zNear = 0
camera.zFar = 100
cameraNode.camera = camera
sceneView.scene.rootNode.addChildNode(cameraNode)
Then I call my setup function to place the virtual Display next to all my AR stuff, position the cameraNode as well (pointing in the direction where objects stay in the scene)
cameraNode.position = SCNVector3(initialStartPosition.x, initialStartPosition.y + 0.5, initialStartPosition.z)
let cameraPlane = SCNNode(geometry: SCNPlane(width: 0.5, height: 0.3))
cameraPlane.geometry?.firstMaterial?.diffuse.contents = cameraNode.camera
cameraPlane.position = SCNVector3(initialStartPosition.x - 1.0, initialStartPosition.y + 0.5, initialStartPosition.z)
sceneView.scene.rootNode.addChildNode(cameraPlane)
Everything compiles and loads... The display shows up at the given position, but it stays entirely gray. Nothing is displayed at all from the SCNCamera I put in the scene. Everything else in the AR scene works well, I just don't get any feed from that camera.
Hay anyone an approach to get this scenario working?
To even better visualize, I add some more print screens.
The following shows the Image trough the SCNCamera according to ARGeo's input. But it takes the whole screen, instead of displaying its contents on a SCNPlane, like I need.
The next Print screen actually shows the current ARView result as I got it using my posted code. As you can see, the gray Display-Plane remains gray - it shows nothing.
The last print screen is a photomontage, showing the expected result, as I'd like to get.
How could this be realized? Am I missing something fundamental here?
After some research and sleep, I came to the following, working solution (including some inexplainable obstacles):
Currently, the additional SCNCamera feed is not linked to a SCNMaterial on a SCNPlane, as it was the initial idea, but I will use an additional SCNView (for the moment)
In the definitions I add an other view like so:
let overlayView = SCNView() // (also tested with ARSCNView(), no difference)
let camera = SCNCamera()
let cameraNode = SCNNode()
then, in viewDidLoad, I setup the stuff like so...
camera.automaticallyAdjustsZRange = true
camera.usesOrthographicProjection = false
cameraNode.camera = camera
cameraNode.camera?.focalLength = 50
sceneView.scene.rootNode.addChildNode(cameraNode) // add the node to the default scene
overlayView.scene = scene // the same scene as sceneView
overlayView.allowsCameraControl = false
overlayView.isUserInteractionEnabled = false
overlayView.pointOfView = cameraNode // this links the new SCNView to the created SCNCamera
self.view.addSubview(overlayView) // don't forget to add as subview
// Size and place the view on the bottom
overlayView.frame = CGRect(x: 0, y: 0, width: self.view.bounds.width * 0.8, height: self.view.bounds.height * 0.25)
overlayView.center = CGPoint(x: self.view.bounds.width * 0.5, y: self.view.bounds.height - 175)
then, in some other function, I place the node containing the SCNCamera to my desired position and angle.
// (exemplary)
cameraNode.position = initialStartPosition + SCNVector3(x: -0.5, y: 0.5, z: -(Float(shiftCurrentDistance * 2.0 - 2.0)))
cameraNode.eulerAngles = SCNVector3(-15.0.degreesToRadians, -15.0.degreesToRadians, 0.0)
The result, is a kind of window (the new SCNView) at the bottom of the screen, displaying the same SceneKit content as in the main sceneView, viewed trough the perspective of the SCNCamera plus its node position, and that very nicely.
In a common iOS/Swift/ARKit project, this construct generates some side effects, that one may struggle into.
1) Mainly, the new SCNView shows SceneKit content from the desired perspective, but the background is always the actual physical camera feed. I could not figure out, how to make the background a static color, by still displaying all the SceneKit content. Changing the new scene's background property affects also the whole main scene, what is actually NOT desired.
2) It might sound confusing, but as soon as the following code get's included (which is essential to make it work):
overlayView.scene = scene
the animation speed of the entire scenes (both) DOUBLES! (Why?)
I got this corrected by adding/changing the following property, which restores the animation speed behavour almost like normal (default):
// add or change this in the scene setup
scene.physicsWorld.speed = 0.5
3) If there are actions like SCNAction.playAudio in the project, all the effects will no longer play - as long as I don't do this:
overlayView.scene = nil
Of course, the additional SCNView stops working but everything else gets gets back to its normal.
Use this code (as a starting point) to find out how to setup a virtual camera.
Just create a default ARKit project in Xcode and copy-paste my code:
import UIKit
import SceneKit
import ARKit
class ViewController: UIViewController, ARSCNViewDelegate {
#IBOutlet var sceneView: ARSCNView!
override func viewDidLoad() {
super.viewDidLoad()
sceneView.delegate = self
sceneView.showsStatistics = true
let scene = SCNScene(named: "art.scnassets/ship.scn")!
sceneView.scene = scene
let cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3(0, 0, 1)
cameraNode.camera?.focalLength = 70
cameraNode.camera?.categoryBitMask = 1
scene.rootNode.addChildNode(cameraNode)
sceneView.pointOfView = cameraNode
sceneView.allowsCameraControl = true
sceneView.backgroundColor = UIColor.darkGray
let plane = SCNNode(geometry: SCNPlane(width: 0.8, height: 0.45))
plane.position = SCNVector3(0, 0, -1.5)
// ASSIGN A VIDEO STREAM FROM SCENEKIT-RECORDER TO YOUR MATERIAL
plane.geometry?.materials.first?.diffuse.contents = capturedVideoFromSceneKitRecorder
scene.rootNode.addChildNode(plane)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
let configuration = ARWorldTrackingConfiguration()
sceneView.session.run(configuration)
}
}
UPDATED:
Here's a SceneKit Recorder App that you can tailor to your needs (you don't need to write a video to disk, just use a CVPixelBuffer stream and assign it as a texture for a diffuse material).
Hope this helps.
I'm a little late to the party, but I've had a similar issue recently.
As far as I can tell, you cannot directly connect a camera to a node's material. You can, however, use a scene's layer as a texture for a node.
The code below is not verified, but should be more or less ok:
class MyViewController: UIViewController {
override func loadView() {
let projectedScene = createProjectedScene()
let receivingScene = createReceivingScene()
let projectionPlane = receivingScene.scene?.rootNode.childNode(withName: "ProjectionPlane", recursively: true)!
// Here's the important part:
// You can't directly connect a camera to a material's diffuse texture.
// But you can connect a scene's layer as a texture.
projectionPlane.geometry?.firstMaterial?.diffuse.contents = projectedScene.layer
projectedScene.layer.contentsScale = 1
// Note how we only need to connect the receiving view to the controller.
// The projected view is not directly connected as a subview,
// but updates in projectedScene will still be reflected in receivingScene.
self.view = receivingScene
}
func createProjectedScene() -> SCNView {
let view = SCNView()
// ... set up scene ...
return view
}
func createReceivingScene() -> SCNView {
let view = SCNView()
// ... set up scene ...
let projectionPlane = SCNNode(geometry: SCNPlane(width: 2, height: 2)
projectionPlane.name = "ProjectionPlane"
view.scene.rootNode.addChildNode(projectionPlane)
return view
}
}
I am trying to blur my entire GameScene when my pause button is pressed. I have a method called blurSceen() but it doesn't seem to be adding the effect to the scene. Is there a way I can accomplish this or am I doing something wrong? I have viewed other posts about this topic but haven't been able to accomplish the effect.
func blurScreen() {
let effectsNode = SKEffectNode()
let filter = CIFilter(name: "CIGaussianBlur")
let blurAmount = 10.0
filter!.setValue(blurAmount, forKey: kCIInputRadiusKey)
effectsNode.filter = filter
effectsNode.position = self.view!.center
effectsNode.blendMode = .Alpha
// Add the effects node to the scene
self.addChild(effectsNode)
}
From the SKEffectNode docs:
An SKEffectNode object renders its children into a buffer and optionally applies a Core Image filter to this rendered output.
The effect node applies a filter only to its child nodes. Your effect node has no children, so there's nothing to apply a filter to.
Probably what you want is to add an effect node to your scene early on--but don't set the filter on it yet--and put all the nodes that you'll later want to blur in as its children. When it comes time to apply a blur, set the filter on the (already existing, already with children) effect node.
I had the same issue trying to blur the whole SKScene and it just wasn't working. The missing piece of the puzzle was this line:
shouldEnableEffects = true
Swift 4:
from gameScene:
let blur = CIFilter(name:"CIGaussianBlur",withInputParameters: ["inputRadius": 10.0])
self.filter = blur
self.shouldRasterize = true
self.shouldEnableEffects = true
I'm creating a game where the player can control a cube.
He could buy new cubes.
I created the basic cube like that :
// MAIN CUBE
mainCubeGeometry = SCNBox(width: 0.2, height: 0.2, length: 0.2, chamferRadius: 0.0)
mainCubeGeometry.firstMaterial?.diffuse.contents = UIColor.redColor()
mainCubeNode = SCNNode(geometry: mainCubeGeometry)
mainCubeNode.position = SCNVector3(x: 0.0, y: 0.0, z: 0.0)
scene.rootNode.addChildNode(mainCubeNode)
I would like to know how use 3D models (dae) of cubes created on any software (SketchUp per exemple). I don't really understand how to load the 3D file when the scene is created (scene = SCNScene(named: "3d.scnassets/cube.dae")) because it is a scene, so it import a scene into my original scene, while I just want to import a 3D model in a node to use it like my basic cube.
Thanks for your help !
SCNScene(named:) returns an SCNNode with all of the objects from that DAE file as child nodes. Load the file, retrieve the bodies you're interested in, and add them to your scene's root node.
Here are a couple of snippets from the Fox sample app from WWDC 2015. The Character class has a node property initialized like this:
let characterScene = SCNScene(named: "game.scnassets/panda.scn")!
let characterTopLevelNode = characterScene.rootNode.childNodes[0]
node.addChildNode(characterTopLevelNode)
And then add the character to the scene like this:
// Add the character to the scene.
scene.rootNode.addChildNode(character.node)
SOLUTION
I found a solution on this post : How do you load a .dae file into an SCNNode in IOS SceneKit?
class func collada2SCNNode(filepath:String) -> SCNNode {
var node = SCNNode()
let scene = SCNScene(named: filepath)
var nodeArray = scene!.rootNode.childNodes
for childNode in nodeArray {
node.addChildNode(childNode as SCNNode)
}
return node
}
Use :
let myNode = collada2SCNNode("nodes.scnassets/node.dae")
scene.rootNode.addChildNode(myNode)
I'm working in a side-scolling game and I need to know what nodes are in an area to implement something like "line of sight". Right now I'm trying using enumerateBodyiesInRect() however it's detecting bodies that are 20px or more from the evaluated rect and I cannot figure out why it's so imprecise.
This is what I'm trying now:
import SpriteKit
import CoreMotion
class GameScene: SKScene, SKPhysicsContactDelegate
{
var player = SKShapeNode()
var world = SKShapeNode()
var rShape = SKShapeNode()
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
self.scaleMode = SKSceneScaleMode.AspectFit
self.size = view.bounds.size
// Add world
world = SKShapeNode(rectOfSize: view.bounds.size)
world.physicsBody = SKPhysicsBody(edgeLoopFromPath: world.path)
world.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2) // Move camera
self.addChild(world)
// Add player
player = SKShapeNode(rectOfSize: CGSize(width: 25, height: 25))
player.physicsBody = SKPhysicsBody(rectangleOfSize: player.frame.size)
player.physicsBody.dynamic = false
player.strokeColor = SKColor.blueColor()
player.fillColor = SKColor.blueColor()
player.position = CGPointMake(90, -50)
world.addChild(player)
}
override func update(currentTime: CFTimeInterval) {
// Define rect position and size (area that will be evaluated for bodies)
var r : CGRect = CGRect(x: 200, y: 200, width: 25, height: 25)
// Show rect for debug
rShape.removeFromParent()
rShape = SKShapeNode(rect: r)
rShape.strokeColor = SKColor.redColor()
self.addChild(rShape)
// Evaluate rect
rShape.fillColor = SKColor.clearColor()
self.physicsWorld.enumerateBodiesInRect(r) {
(body: SKPhysicsBody!, stop: UnsafePointer<ObjCBool>) in
self.rShape.fillColor = SKColor.redColor() // Paint the area blue if it detects a node
}
}
}
This code should show the evaluated rect and ray on the screen (for debugging purposes) and paint them red if they contact the player node. However you can see in the screenshot how it turns red when the player is 25px or more away from it, it's like if the drawing is a little bit off, or smaller than the actual area being evaluated. You can copy paste it to a project to duplicate the problem.
Could this be because this is just beta or am I doing something wrong?
You are creating a physical world where there is a specific rectangle that has 'special properties' - this is the rectangle that you use in enumerateBodiesInRect(). Why not create an invisible, inert physical body with the required rectangular dimension and then use SKPhysicsBody to check for collisions and/or contacts? You could then use allContactedBodies() or some delegate callbacks to learn what other bodies are inside your special rectangle.
Think of it like a 'tractor beam' or a 'warp rectangle'.
I believe you want SKPhysicsWorld's enumerateBodyiesInRect() instance method, which will iterate over all nodes in a given rectangle. If you're looking to get at the physics world through your scene, usage could look like this:
self.physicsWorld.enumerateBodiesInRect(CGRect(x: 0, y: 0, width: 50, height: 50)) {(body: SKPhysicsBody!, stop: UnsafePointer<ObjCBool>) in
// enumerates all nodes in given frame
}
I've experimented quite a bit with enumerateBodiesInRect now, and I've found it to be incredibly inaccurate. It seems to not have any of the claimed functionality, and instead produces random results. I honestly cannot even determine any pattern from its products.
enumerateBodiesAlongRay seems better, but still very buggy. The problem with that function seems to be the conversion between Screen and PhysicsWorld coordinates. I would avoid that one, as well.
I think your solution should simply be to use the existing contact detection system. All of your desired functionality can be written in the didBeginContact() and didEndContact() functions. This has the added benefit of allowing you to specify distinct functionality for both entering and leaving the area. You can also add particle effects, animations, and similar, as well as intentionally ignoring specific types of nodes.
The only thing to ensure success with this method is to clarify that the contact area has a unique category, that the contactTestBitMask contains all desired nodes and the collisionBitMask is set to 0.
The enumerateBodiesInRect method of SKPhysicsWorld expects the rect parameter to be in scene coordinates. This is important. If you have a scene hierarchy of nodes, you need to convert the rect you calculate from a reference node to the scene coordinates.
I faced a lot of issues with this method returning bodies that were off by values like 30px to the left etc. and finally realized the issue was because of the rect parameter not defined in scene coordinate space.
In my case, I had a worldNode inside my scene, and all objects were created in the worldNode. My camera was moving the worldNode about, and applying scaling to it for zooming out and in.
In order to use enumerateBodiesInRect correctly, I had to do something as follows:
// get your world rect based on game logic
let worldRect = getWorldRect()
// calculate the scene rect
let sceneRectOrigin = scene.convertPoint(worldRect.origin, fromNode:scene.worldNode)
let worldScale = scene.worldNode.xScale // assert this is not 0
// now to get the scene rect relative to the world rect, in scene coordinates
let sceneRect = CGRectMake( sceneRectOrigin.x, sceneRectOrigin.y, worldRect.width / worldScale, worldRect.height / worldScale)
world.physicsWorld.enumerateBodiesInRect(sceneRect) {
// your code here
}
Hope this helps.
I am not sure if this is a good practice. Correct me if not. But I am using
let shapeNode = SKShapeNode()
shapeNode.intersects(playerNode)
I checked selected nodes with simple loop if they intersect the player. Additionally I created SKShapeNodes which are drawn in front of nodes representing view sight of other actors in the game. They are moved along those actors.
There is only nodesAtPoint: method.
To achieve what you want you'd better to store all enemies in an array and have an int variable, something like nextEnemyIndex. This approach lets you to easily return the next enemy node, it's much more efficient than trying to find a node on the scene.
yes problem may occur because of your player's image, for example try to use 10px smaller body size:
player.physicsBody = SKPhysicsBody(rectangleOfSize: CGRectMake(self.frame.origin.x, self.frame.origin.y, self.size.width-10, self.size.height-10)));