I'm new to SceneKit... trying to get some basic stuff working without much success so far. For some reason when I try to apply a png texture to a CNBox I end up with nothing but blackness. Here is the simple code snippet I have in viewDidLoad:
let sceneView = (view as SCNView)
let scene = SCNScene()
let boxGeometry = SCNBox(width: 10.0, height: 10.0, length: 10.0, chamferRadius: 1.0)
let mat = SCNMaterial()
mat.locksAmbientWithDiffuse = true
mat.diffuse.contents = ["sofb.png","sofb.png","sofb.png","sofb.png","sofb.png", "sofb.png"]
mat.specular.contents = UIColor.whiteColor()
boxGeometry.firstMaterial = mat
let boxNode = SCNNode(geometry: boxGeometry)
scene.rootNode.addChildNode(boxNode)
sceneView.scene = scene
sceneView.autoenablesDefaultLighting = true
sceneView.allowsCameraControl = true
What it ends up looking like is a white light source reflecting off of a black cube against a black background. What am I missing? I appreciate all responses
If you had different images, you would build a different SCNMaterial object from each like so:
let material_L = SCNMaterial()
material_L.diffuse.contents = UIImage(named: "CapL")
Here, CapL refers to a .png file that has been stored in the project's Assets.xcassets folder. After building 6 such objects, you hand them to the boxNode as follows:
boxGeometry.materials = [material_L, material_green_r, material_K, material_purple_r, material_g, material_j]
Note that "boxGeometry" would be better named "box" or "cube". Also, it would be a good idea to do that work in a new class in your project, constructed like:
class BoxScene: SCNScene {
Which you would then call with modern Swift in your viewController's viewDidLoad method like this:
let scnView = self.view as! SCNView
scnView.scene = BoxScene()
(For that let statement to work, go to Main.storyboard -> View Controller Scene -> View Controller -> View -> Identity icon Then under Custom Class, change it from UIView to SCNView. Otherwise, you receive an error message, like:
Could not cast value of type 'UIView' to 'SCNView'
Passing an array of images (to create a cube map) is only supported by the reflective material property and the scene's background.
In your case, all the images are the same, so you would only have to assign the image (not an array) to the contents to have it appear on all sides of the box
Related
I am trying to add normal map for a 3D model in swift using SCNMaterial properties. The diffuse property is working but no other property including normal property is visible on the screen. When I debug to check if the node's material consists of the normal property, it shows the property exists with the image that I added.
I have also checked if the normal image that I am using is correct or not in the SceneKit Editor where it works fine.
I have added the code that I am using.
let node = SCNNode()
node.geometry = SCNSphere(radius: 0.1)
node.geometry!.firstMaterial!.diffuse.contents = UIColor.lightGray
node.geometry!.firstMaterial!.normal.contents = UIImage(named: "normal")
node.position = SCNVector3(0,0,0)
sceneView.scene.rootNode.addChildNode(node)
This is the output I am getting
I am expecting something like this
I got the solution. Since I did not enable DefaultLighting, there was no lighting in the scene. Added this to the code.
sceneView.autoenablesDefaultLighting = true
Given the screenshot, it seems like there is no lighting in the scene, or the material does not respond to lighting, since the sphere is not shaded. For a normal map to work, lighting has to be taken into account, because it responds to lighting direction. Have you tried creating an entirely new SCNMaterial and played with its properties? (I.E. https://developer.apple.com/documentation/scenekit/scnmaterial/lightingmodel seems interesting)
I would try setting
node.geometry!.firstMaterial!.lightingModel = .physicallyBased
Try this.
let scene = SCNScene()
let sphere = SCNSphere(radius: 0.1)
let sphereMaterial = SCNMaterial()
sphereMaterial.diffuse.contents = UIImage(named: "normal.png")
let sphereNode = SCNNode()
sphereNode.geometry = sphere
sphereNode.geometry?.materials = [sphereMaterial]
sphereNode.position = SCNVector3(0.5,0.1,-1)
scene.rootNode.addChildNode(sphereNode)
sceneView.scene = scene
I am new in ARKit2 and followed a couple of tutorials and official documentation.
problem
How to add 3d object as SCNNode()?
Code
let artFrame = SCNBox(width: CGFloat(w), height: CGFloat(h), length: 0.002, chamferRadius: 0.02)
artFrame.firstMaterial?.diffuse.contents = imageToDisplay
let artFrameNode = SCNNode(geometry: artFrame)
artFrameNode.physicsBody = SCNPhysicsBody(type: .static, shape: SCNPhysicsShape(geometry: artFrame, options: nil))
artFrameNode.position = SCNVector3Make(Float(x), Float(y), Float(z*3))
sceneView.scene.rootNode.addChildNode(artFrameNode)
As per the above code, I am using predefined SCNBox in SCNNode. Is there any way that I can use 3d object such as .dae, .obj instead of SCNBox and wrap with Image?
I check out the documentation and it says that you can add Mesh objects to SCNNode :
https://developer.apple.com/documentation/scenekit/scnnode/1419841-init
Edit
Whenever I am adding a new .dae and converting to .scn. Xcode is throwing follwing error:
/Users/paly/Library/Developer/Xcode/DerivedData/sample-bohiilnhthuwfkechtmhscucgccc/Build/Products/Debug-iphoneos/sample.app: resource fork, Finder information, or similar detritus not allowed
Command CodeSign failed with a nonzero exit code
To add .dae or .obj object to the scene, you need to get childNode of the .dae object and simply add it to your scene. I recommend to convert your .dae file to .scn simply using Xcode's Editor menu.
You also need the node's name, which can be accessed in Scene Graph View. Just click on your .obj file and click the Scene Graph View button on bottom left corner of the Xcode scene editor. Here, my node's name is "objectNode":
Now you can add the 3D object as a SCNNode to your scene:
override func viewDidLoad() {
super.viewDidLoad()
...
let objectScene = SCNScene(named: "object.scn") // Here, add your .obj or .scn file
let objectNode: SCNNode = objectScene.rootNode.childNode(withName: "YourObjectName", recursively: true) // Get the object name from Scene Graph View, which is "objectNode" for me.
objectNode.position = SCNVector3(0,0,-4)
let scene = SCNScene() // Main scene of the app
scene.rootNode.addChildNode(objectNode)
sceneView.scene = scene
...
}
I created a basic scene, and added an dae file.
First every time i run or save the project i get the popup:
The document “billboard.dae” could not be saved.
It still runs though but is annoying.
But the issue is I can't scale the object.
I have tried different values 0.5s and also > 1 but nothing seems to work. Here is my code
override func viewDidLoad()
{
super.viewDidLoad()
sceneView.delegate = self
sceneView.showsStatistics = true
let scene = SCNScene(named: "art.scnassets/billboard.dae")!
let billboardNode = scene.rootNode.childNode(withName: "billboard", recursively: true)
// billboardNode?.position = SCNVector3Make(0, 0, 1)
billboardNode?.position.z = 10
billboardNode?.scale.z = 0.5
// billboardNode?.scale = SCNVector3Make(0.4,0.4, 0.4)
sceneView.scene = scene
}
Any ideas?
Thanks
Have you verified billboardNode is not nil? You're sending an optional (the result of looking for a child node with a given name) position and scaling messages but if it's nil (because finding the child node failed) it won't have any impact.
The error suggests to me there was some problem converting the .dae file, which might explain why the scene can't locate the asset by name. Or it might be as simple as "billboard" vs. "Billboard".
I am trying to create a 3d model that is moving above a 2d background. I read somewhere else that in order to do that I need to create a SCNNode() with SCNPlane() geometry and use my backgroundimage as the material of the SCNPlane(). However I have no clue how to add materials to a geometry structure, can you help me?
So far this is my code:
let background = SCNNode()
background.geometry = SCNPlane()
First add your texture image to your assets catalogue, say "Background.jpg", to Assets.xcassets
Then
let background = SCNNode()
background.geometry = SCNPlane.init(width: 100, height: 100) // better set its size
background.geometry?.firstMaterial?.diffuse.contents = "Background.jpg"
scene.rootNode.addChildNode(background)
SKEffectionNodes have a shouldRasterise "switch" that bakes them into a bitmap, and doesn't update them until such time as the underlying nodes that are impacted by the effect are changed.
However I can't find a way to create an SKTexture from this rasterised "image".
Is it possible to get a SKTexture from a SKEffectNode?
I think you could try a code like this (it's just an example):
if let effect = SKEffectNode.init(fileNamed: "myeffect") {
effect.shouldRasterize = true
self.addChild(effect)
...
let texture = SKView().texture(from: self)
}
Update:
After you answer, hope I understood better what do you want to achieve.
This is my point of view: if you want to make a shadow of a texture, you could simply create an SKSpriteNode with this texture:
let shadow = SKSpriteNode.init(texture: <yourTexture>)
shadow.blendMode = SKBlendMode.alpha
shadow.colorBlendFactor = 1
shadow.color = SKColor.black
shadow.alpha = 0.25
What I want to say is that you could proceed step by step:
get your texture
elaborate your texture (add filters, make some other effect..)
get shadow
This way of working produces a series of useful methods you could use in your project to build other kind of elements.
Maybe, by separating the tasks you don't need to use texture(from:)
I've figured this out, in a way that solves my problems, using a Factory.
Read more on how to make a factory, from BenMobile's patient and clear articulation, here: Factory creation and use for making Sprites and Shapes
There's an issue with blurring a SKTexture or SKSpriteNode in that it's going to run out of space. The blur/glow goes beyond the edges of the sprite. To solve this, in the below, you'll see I've created a "framer" object. This is simply an empty SKSpriteNode that's double the size of the texture to be blurred. The texture to be blurred is added as a child, to this "framer" object.
It works, regardless of how hacky this is ;)
Inside a static factory class file:
import SpriteKit
class Factory {
private static let view:SKView = SKView() // the magic. This is the rendering space
static func makeShadow(from source: SKTexture, rgb: SKColor, a: CGFloat) -> SKSpriteNode {
let shadowNode = SKSpriteNode(texture: source)
shadowNode.colorBlendFactor = 0.5 // near 1 makes following line more effective
shadowNode.color = SKColor.gray // makes for a darker shadow. White for "glow" shadow
let textureSize = source.size()
let doubleTextureSize = CGSize(width: textureSize.width * 2, height: textureSize.height * 2)
let framer = SKSpriteNode(color: UIColor.clear, size: doubleTextureSize)
framer.addChild(shadowNode)
let blurAmount = 10
let filter = CIFilter(name: "CIGaussianBlur")
filter?.setValue(blurAmount, forKey: kCIInputRadiusKey)
let fxNode = SKEffectNode()
fxNode.filter = filter
fxNode.blendMode = .alpha
fxNode.addChild(framer)
fxNode.shouldRasterize = true
let tex = view.texture(from: fxNode) // ‘view’ refers to the magic first line
let shadow = SKSpriteNode(texture: tex) //WHOOPEE!!! TEXTURE!!!
shadow.colorBlendFactor = 0.5
shadow.color = rgb
shadow.alpha = a
shadow.zPosition = -1
return shadow
}
}
Inside anywhere you can access the Sprite you want to make a shadow or glow texture for:
shadowSprite = Factory.makeShadow(from: button, rgb: myColor, a: 0.33)
shadowSprite.position = CGPoint(x: self.frame.midX, y: self.frame.midY - 5)
addChild(shadowSprite)
-
button is a texture of the button to be given a shadow. a: is an alpha setting (actually transparency level, 0.0 to 1.0, where 1.0 is fully opaque) the lower this is the lighter the shadow will be.
The positioning serves to drop the shadow slightly below the button so it looks like light is coming from the top, casting shadows down and onto the background.