On reality kit, I've tried to give a physicsBodyComponent to a modelEntity.
But as I put to modelEntity to real world, It just fall down.
Is there anyway to fix this?
You need to create a floor mesh with a PhysicsBodyComponent:
let floor = ModelEntity(mesh: .generateBox(size: [1000, 0, 1000]), materials: [SimpleMaterial()])
floor.generateCollisionShapes(recursive: true)
if let collisionComponent = floor.components[CollisionComponent] as? CollisionComponent {
floor.components[PhysicsBodyComponent] = PhysicsBodyComponent(shapes: collisionComponent.shapes, mass: 0, material: nil, mode: .static)
floor.components[ModelComponent] = nil // make the floor invisible
}
scene?.addChild(floor)
Then, when you load your entities, you also give them a PhysicsBodyComponent (and they need a non-zero mass, otherwise they will anyways fall through, which is what eluded me for a long time):
var loadModelCancellable: AnyCancellable? = nil
loadModelCancellable = Entity.loadModelAsync(named: modelUri)
.sink(receiveCompletion: { _ in
loadModelCancellable?.cancel()
}, receiveValue: { entity in
entity.generateCollisionShapes(recursive: true)
if let collisionComponent = entity.components[CollisionComponent] as? CollisionComponent {
entity.components[PhysicsBodyComponent] = PhysicsBodyComponent(shapes: collisionComponent.shapes, mass: 1, material: nil, mode: .dynamic)
}
scene.addChild(entity)
loadModelCancellable?.cancel()
})
In the end, adding physics to my project had too many unintended consequences for what I was trying to do (just preventing models to overlap), like models pushing each other, and movements needing to be redone completely, ... So I didn't get further than this, but at least this should let you add physics to your models without them falling indefinitely from gravity.
Related
I'm kind of stuck right now when it comes to applying a specific texture on my 3d obj model.
Easiest solution of all would be to do let test = SCNScene(named: "models.scnassets/modelFolder/ModelName.obj"), but this requires that the mtl file maps the texture file directly inside of it which is not something that's possible with my current workflow.
With my current understanding, this leaves me with the option of using a scattering function to apply textures to a specific semantic, something like such :
if let url = URL(string: obj) {
let asset = MDLAsset(url: url)
guard let object = asset.object(at: 0) as? MDLMesh else {
print("Failed to get mesh from asset.")
self.presentAlert(title: "Warning", message: "Could not fetch the model.", firstBtn: "Ok")
return
}
// Create a material from the various textures with a scatteringFunction
let scatteringFunction = MDLScatteringFunction()
let material = MDLMaterial(name: "material", scatteringFunction: scatteringFunction)
let property = MDLMaterialProperty(name: "texture", semantic: .baseColor, url: URL(string: self.textureURL))
material.setProperty(property)
// Apply the texture to every submesh of the asset
object.submeshes?.forEach {
if let submesh = $0 as? MDLSubmesh {
submesh.material = material
}
}
// Wrap the ModelIO object in a SceneKit object
let node = SCNNode(mdlObject: object)
let scene = SCNScene()
scene.rootNode.addChildNode(node)
// Set up the SceneView
sceneView.scene = scene
...
}
The actual problem is the semantics. The 3d models are made on Unreal and for many models there's a png texture which has 3 semantics inside of it, namely Ambient Occlusion, Roughness and Metallic. Ambient Occlusion would need to be applied on the red channel, Roughness on the greed channel and Metallic on the blue channel.
How could I achieve this? An MdlMaterialSemantic has all of these possible semantics, but metallic, ambient occlusion and roughness are all separate. I tried simply applying the texture on each, but obviously this did not work very well.
Considering that my .png texture has all of those 3 "packaged" in it under a different channel, how can I work with this? I was thinking that maybe I could somehow use a small script to add mapping to the texture in the mtl file on my end in the app directly, but this seems sketchy lol..
What are my other options if there's no way of doing this? I've also been trying to use fbx files with assimpKit, but I couldn't manage to load any textures, just the model in black...
I am open to any suggestion, if more info is needed, please let me know! Thank you very much!
Sorry, I don't have enough rep to comment, but this might be more of a comment than an answer!
Have you tried loading the texture png image separately (as a NS/UI/CGImage) and then splitting it into three channels manually, then applying these channels separately? (Splitting into three separate channels is not as simple as it could be... but you could use this grayscale conversion for guidance, and just do one channel at a time.)
Once you have your objects in SceneKit, it is possibly slightly easier to modify these materials. Once you have a SCNNode with a SCNGeometry with a SCNMaterial you can access any of these materials and set the .contents property to almost anything (including a XXImage).
Edit:
Here's an extension you can try to extract the individual channels from a CGImage using Accelerate. You can get a CGImage from an NSImage/UIImage depending on whether you're on Mac or iOS (and you can load the file directly into one of those image formats).
I've just adapted the code from the link above, I am not very experienced with the Accelerate framework, so use at your own risk! But hopefully this puts you on the right path.
extension CGImage {
enum Channel {
case red, green, blue
}
func getChannel(channel: Channel) -> CGImage? {
// code adapted from https://developer.apple.com/documentation/accelerate/converting_color_images_to_grayscale
guard let format = vImage_CGImageFormat(cgImage: cgImage) else {return nil}
guard var sourceImageBuffer = try? vImage_Buffer(cgImage: cgImage, format: format) else {return nil}
guard var destinationBuffer = try? vImage_Buffer(width: Int(sourceImageBuffer.width), height: Int(sourceImageBuffer.height), bitsPerPixel: 8) else {return nil}
defer {
sourceImageBuffer.free()
destinationBuffer.free()
}
let redCoefficient: Float = channel == .red ? 1 : 0
let greenCoefficient: Float = channel == .green ? 1 : 0
let blueCoefficient: Float = channel == .blue ? 1 : 0
let divisor: Int32 = 0x1000
let fDivisor = Float(divisor)
var coefficientsMatrix = [
Int16(redCoefficient * fDivisor),
Int16(greenCoefficient * fDivisor),
Int16(blueCoefficient * fDivisor)
]
let preBias: [Int16] = [0, 0, 0, 0]
let postBias: Int32 = 0
vImageMatrixMultiply_ARGB8888ToPlanar8(&sourceImageBuffer,
&destinationBuffer,
&coefficientsMatrix,
divisor,
preBias,
postBias,
vImage_Flags(kvImageNoFlags))
guard let monoFormat = vImage_CGImageFormat(
bitsPerComponent: 8,
bitsPerPixel: 8,
colorSpace: CGColorSpaceCreateDeviceGray(),
bitmapInfo: CGBitmapInfo(rawValue: CGImageAlphaInfo.none.rawValue),
renderingIntent: .defaultIntent) else {return nil}
guard let result = try? destinationBuffer.createCGImage(format: monoFormat) else {return nil}
return result
}
}
I want to make the physics world without friction and damping.
I tried to make the scene's gravity to (0,0,0), and make a square and ball, give force when tapping. I want to make the ball move eternally, but it just stop in some time.
How can I make the entities friction to zero?
Apply a new Physics Material to your model entity.
For this use generate(friction:restitution:) type method:
static func generate(friction: Float = 0,
restitution: Float = 0) -> PhysicsMaterialResource
where
/* the coefficient of friction is in the range [0, infinity] */
/* and the coefficient of restitution is in the range [0, 1] */
Here's a code:
arView.environment.background = .color(.darkGray)
let mesh = MeshResource.generateSphere(radius: 0.5)
let material = SimpleMaterial()
let model = ModelEntity(mesh: mesh,
materials: [material]) as (ModelEntity & HasPhysics)
let physicsResource: PhysicsMaterialResource = .generate(friction: 0,
restitution: 0)
model.components[PhysicsBodyComponent] = PhysicsBodyComponent(
shapes: [.generateSphere(radius: 0.51)],
mass: 20, // in kilograms
material: physicsResource,
mode: .dynamic)
model.generateCollisionShapes(recursive: true)
let anchor = AnchorEntity()
anchor.addChild(model)
arView.scene.anchors.append(anchor)
P.S. Due to some imperfectness of physics engine in RealityKit, I suppose there's no possibility to create an eternal bouncing. Seemingly next RealityKit's update will fix physics engine imperfectness.
I am trying to add SCNNode mutiple time in a loop at different position but I can see same type of node at once with the last position.
Below is the code
let entityArray:[entity] = [.coin, .coin, .coin, .brick, .coin, .coin, .coin, .brick]
func setupworld() {
let scene = SCNScene(named: "art.scnassets/MainScene.scn")!
var zPosition = -10
var count = 0
let delta = -4
for entity in entityArray {
var node = SCNNode()
switch entity {
case .coin:
node = scene.rootNode.childNode(withName: "coin", recursively: true) ?? node
node.position = SCNVector3(0, -5, zPosition)
case .brick:
node = scene.rootNode.childNode(withName: "brick", recursively: true) ?? node
node.position = SCNVector3(0, 0, zPosition)
}
self.sceneView.scene.rootNode.addChildNode(node)
zPosition += delta
count += 1
}
}
It shows one coin and one brick at last positions.
I am new to scenekit so would be doing something wrong, Please help me.
Building on from the other comments and as #rmaddy has said an SCNNode has a clone() function (which is the approach you should take here) and which simply:
Creates a copy of the node and its children.
One thing to be aware of when using this however, is that each cloned Node will share the same geometry and materials.
That's to say that if you wanted at any point to have some bricks with a red colour and some with a green colour you wouldn't be able to do it with this method since:
changes to the objects attached to one node will affect
other nodes that share the same attachments.
To achieve this e.g. to render two copies of a node using different materials, you must copy both the node and its geometry before assigning a new material, which you can read more about here: Apple Discussion
The reason you are only ever seeing one instance of either the coin or brick is because each time you are iterating through your loop you are saying that the newly created node is equal to either the coin or the brick, so naturally the last element in that loop will be the one that references that element from your scene.
Putting this into practice and solving your issue therefor, your setupWorld function should look like something like this:
/// Sets Up The Coins & Bricks
func setupworld(){
//1. Get Our SCNScene
guard let scene = SCNScene(named: "art.scnassets/MainScene.scn") else { return }
//2. Store The ZPosition
var zPosition = -10
//3. Store The Delta
let delta = -4
//4. Get The SCNNodes We Wish To Clone
guard let validCoin = scene.rootNode.childNode(withName: "coin", recursively: true),
let validBrick = scene.rootNode.childNode(withName: "brick", recursively: true) else { return }
//5. Loop Through The Entity Array & Create Our Nodes Dynamically
var count = 0
for entity in entityArray {
var node = SCNNode()
switch entity{
case .coin:
//Clone The Coin Node
node = validCoin.clone()
node.position = SCNVector3(0, -5, zPosition)
case .brick:
//Clone The Brick Node
node = validBrick.clone()
node.position = SCNVector3(0, 0, zPosition)
}
//6. Add It To The Scene
self.sceneView.scene.rootNode.addChildNode(node)
//7. Adjust The zPosition
zPosition += delta
count += 1
}
}
I've been searching for days about this new framework and trying to make usage of some of it's funcionalities,
but... there're some things that are not fitting together for me, the demobot source code isn't helping at some points,
I miss some kind of simple tutorial but here goes my main doubts:
let obstacles = scene["obstacle"]
polygonObstacles = SKNode.obstaclesFromNodePhysicsBodies(obstacles)
graph = GKObstacleGraph(obstacles: polygonObstacles, bufferRadius: 60.0)
func drawGraph() {
for node in graph.nodes as! [GKGraphNode2D] {
for destination in node.connectedNodes as! [GKGraphNode2D] {
let points = [CGPoint(node.position), CGPoint(destination.position)]
let shapeNode = SKShapeNode(points: UnsafeMutablePointer<CGPoint>(points), count: 2)
shapeNode.strokeColor = SKColor(white: 1.0, alpha: 0.5)
shapeNode.lineWidth = 5.0
shapeNode.zPosition = 3
scene.addChild(shapeNode)
}
}
}
So, when I try to draw this graph and see the connections, I get this: http://i.imgur.com/EZ3dx5v.jpg
I find it really weird, anywhere I put my obstacles, even in low numbers, the left-corner portion of the screen have always more connections(the radius don't have influence on that)
I don't use GKComponents on my game, but I tried to run some GKAgents2D to hunt the player, like this:
func calculateBehaviorForAgents(){
let mainCharacterPosition = float2(scene.mainCharacter.position)
let mainCharacterGraphNode = GKGraphNode2D(point: mainCharacterPosition)
graph.connectNodeUsingObstacles(mainCharacterGraphNode)
for i in 0...monsters.count-1{
let monster = monsters[i]
let agent = agents[i]
let behavior = GKBehavior()
let monsterPosition = float2(monster.position)
let monsterGraphNode = GKGraphNode2D(point: monsterPosition)
graph.connectNodeUsingObstacles(monsterGraphNode)
let pathNodes = graph.findPathFromNode(monsterGraphNode, toNode: mainCharacterGraphNode) as! [GKGraphNode2D]
let path = GKPath(graphNodes: pathNodes, radius: 00.0)
let followPathGoal = GKGoal(toFollowPath: path, maxPredictionTime: 1.0, forward: true)
behavior.setWeight(1.0, forGoal: followPathGoal)
let stayOnPathGoal = GKGoal(toStayOnPath: path, maxPredictionTime: 1.0)
behavior.setWeight(1.0, forGoal: stayOnPathGoal)
agent.behavior = behavior
graph.removeNodes([monsterGraphNode])
}
graph.removeNodes([mainCharacterGraphNode])
}
Now when I call the updateWithDeltaTime method, his delegate methods:
func agentWillUpdate(agent: GKAgent){}
func agentDidUpdate(agent: GKAgent){}
give me unexpected values for the agents, it's position doesn't make any sense, with giant numbers that leads to outside of the battlefield
But I saw that the his velocity vector were making sense, so I matched it to my monster and updated the agent to the monster's position
func updateWithDeltaTime(currentTime : CFTimeInterval){
for i in 0...monsters.count-1{
let agent = agents[i]
let monster = monsters[i]
monster.physicsBody?.velocity = CGVectorMake(CGFloat(agent.velocity.x), CGFloat(agent.velocity.y))
agent.updateWithDeltaTime(currentTime)
agent.position = float2(monster.position)
monster.gameSceneUpdate(currentTime)
}
Now I was getting some results, but it's far away from what I want:
The monsters are not following the character to the edges or the right-top portion of screen, I remove their points from the graph but after make a path for them to follow (the image doesn't have this points, but they exists).
Apparently because there was no path leading to there, remember the image?
The question is: how to make this agent system to work?
Maybe I'm totally wrong at the usage of agents, goals and even the graphs! I read the documentation but I still can't make it right
And more...
At first, the monster were not avoid obstacles, even with GKGoals like "avoidObstacles", passing the same PolygonObstacles,
but when I change
graph.connectNodeUsingObstacles(mainCharacterGraphNode)
graph.connectNodeUsingObstacles(monsterGraphNode)
to
graph.connectNodeUsingObstacles(mainCharacterGraphNode, ignoringObstacles: polygonObstacles)
graph.connectNodeUsingObstacles(monsterGraphNode, ignoringObstacles: polygonObstacles)
it worked! o.O
I really need some help, thank you all :D!
I am playing around a little bit in SpriteKit, and am trying to make a stick figure run. Due to my lack of experience, I believe I have started this process in an unconventional way.
Instead of drawing out each individual motion frame, I loaded the Separate images of the stick figure (ie the Head, the knee, the Thigh, the body, the arm, etc.) and told them to move accordingly. So far, everything fits together except for the motion and rotation of knee during the running sequence.
My problem is this:
When the thigh pulls back in it's stride, the knee becomes detached, and follows a straight line to the end of the stride while rotating.
My Question is this:
Is there a way to connect the thigh node to the calf node, as if it they were attached at a "knee" per say, while in motion? or is there some more efficient way?
Here is a snippet of my code, It may be a little more descriptive than I have been.
func thigh_run(){
//running config
//DONT CHANGE!
var thigh_rotation = CGFloat(M_PI)*0.8
//Can Change :)
var run_speed = NSTimeInterval(0.25)
// reset the action sequence... basically
let pos_nuetralize = SKAction.rotateByAngle(thigh_rotation/2, duration: run_speed)
let neg_nuetralize = SKAction.rotateByAngle(-thigh_rotation/2, duration: run_speed)
//strides
let thigh_pull = SKAction.rotateByAngle(-thigh_rotation, duration: run_speed*2)
let thigh_stride = SKAction.rotateByAngle(thigh_rotation/2, duration: run_speed)
// for the opposite leg
let b_thigh_pull = SKAction.rotateByAngle(-thigh_rotation/2, duration: run_speed)
let b_thigh_stride = SKAction.rotateByAngle(thigh_rotation, duration: run_speed*2)
//knee movement
let stride = SKAction.sequence([thigh_stride, thigh_pull, pos_nuetralize])
let pull = SKAction.sequence([b_thigh_pull, b_thigh_stride, neg_nuetralize])
r_arm.runAction(SKAction.repeatActionForever(stride))
f_leg_thigh.runAction(SKAction.repeatActionForever(stride))
b_leg_thigh.runAction(SKAction.repeatActionForever(pull))
//knee_run(run_speed)
}
func knee_run(speed: NSTimeInterval){
let knee_stride = SKAction.moveTo(CGPointMake(f_leg_thigh.position.x+f_leg_thigh.size.height, f_leg_thigh.position.y), duration: speed)
let knee_reset = SKAction.moveTo(CGPointMake(f_leg_thigh.position.x, f_leg_thigh.position.y-f_leg_thigh.size.height), duration: speed)
let knee_pull_rotate = SKAction.rotateToAngle(CGFloat(M_PI)/2, duration: speed, shortestUnitArc: true)
let knee_pull_rotate_half = SKAction.rotateToAngle(CGFloat(M_PI)*2, duration: speed, shortestUnitArc: true)
let knee_pull_half = SKAction.moveTo(CGPointMake(f_leg_thigh.position.x-f_leg_thigh.size.height, f_leg_thigh.position.y/2), duration: speed)
let knee_pull = SKAction.moveTo(CGPointMake(f_leg_thigh.position.x-f_leg_thigh.size.height, f_leg_thigh.position.y), duration: speed)
//Grouping of the knee moving and rotating at the same time
let knee_pull_group_half = SKAction.group([knee_pull_half, knee_pull_rotate_half])
let knee_pull_group = SKAction.group([knee_pull, knee_pull_rotate])
let f_knee_stride_seq = SKAction.sequence([knee_stride,knee_reset,knee_pull,knee_reset])
let f_knee_pull_seq = SKAction.sequence([knee_pull_group_half, knee_reset, knee_stride, knee_reset])
f_leg_calf.runAction(SKAction.repeatActionForever(f_knee_stride_seq))
b_leg_calf.runAction(SKAction.repeatActionForever(f_knee_pull_seq))
}
I understand it may be hard to read, I have Documented it for myself pretty well. the f_ prefix is for "front"leg and b is for "back"_leg. think of it as right leg and left leg however.
Anyway! Thanks in advance! I appreciate any help or tips! Comment for any further explanation! :)
The more efficient way is to use SKPhysicsJoint to connect the thigh node to the calf node.