I have created a mountain landscape in Blender and imported it into my Xcode project.
https://github.com/QBeukelman/Mars_Curiosity.git
I would like to drive the SCNVehicle on the landscape as if it were the floor of the scene (landscapeMountains.scn).
The vehicle falls through the landscape!
I have tried the following to solve the issue, but without success:
Different combinations of static, kinetic and dynamic physics bodies.
Using different collision margins such as 0.01
Using category and collision masks (see image)
Does anyone know how to use a scn object as a floor using SceneKit and Xcode?
category & collision bit masks
Replace your entire "// add mountain" code block (line 185 to 191 in GameViewController.swift) with this:
func floorPhysBody(type: SCNPhysicsBodyType = .static, shape: SCNGeometry, scale: SCNVector3 = SCNVector3(1.0,1.0,1.0)) -> SCNPhysicsBody {
// Create Physics Body and set Physics Properties
let body = SCNPhysicsBody(type: type, shape: SCNPhysicsShape(geometry: shape, options: [SCNPhysicsShape.Option.type: SCNPhysicsShape.ShapeType.concavePolyhedron, SCNPhysicsShape.Option.scale: scale]))
// Physics Config
body.isAffectedByGravity = false
return body
}
// configure Physics Floor
let mountain = scene!.rootNode.childNode(withName: "mountain", recursively: true)!
mountain.physicsBody = floorPhysBody(type: .static, shape: mountain.geometry!)
In addition: Your Mountain Geometry is very large (file is over 50MB in size for some geometry). I recommend you to reduce this, to avoid memory issues when your game grows. Also: try to avoid texture sizes bigger than 1024x1024. Use textures sizes from a power of 2 if possible - like 128px, 256px, 512px, 1024px squared.
Have fun with your project.
Related
I have a scenekit node that I want to add a glow effect to.
let newScene = SCNScene(named: "art.scnassets/cubeOne.scn")!
let newNode = (newScene.rootNode.childNode(withName: "cubeOneNode", recursively: false))!
newNode.geometry?.firstMaterial?.selfIllumination = UIColor.red
newNode.geometry?.firstMaterial?.ambientOcclusion = UIColor.red
sceneView.scene.rootNode.addChildNode(newNode)
You could achieve this by using a so called CIFilter and attach it to you node - but I personally don't recommend this, because it is incredibly performance intense and uses like three times more memory.
I recommend configuring this on your camera. It will also cost you more GPU performance and some memory, but not as much as a CIFilter does. Give it a try:
camera.wantsHDR = true
camera.bloomThreshold = 0.8
camera.bloomIntensity = 2
camera.bloomBlurRadius = 16.0
camera.wantsExposureAdaptation = false
and then use the emission.intensity property of the node material. Set it between 2.0 to 5.0, depending on how much you want the effect to be visible. I usually use the .physicallyBased lighting option for my on scene stuff. (I never tried to use it with selfIllumination.)
PS: Using the red color does not add a very intense effect. Really intense is cyan or green. Using the red color you might screw up the emission.intensity value to 10.0 or higher.
I am working on a scene with a character and a platform with a stairs. Character must move up and down of the stairs and jump from the platform:
I move character by virtual d-pad. I am looking for a correct way to move a character. Now I have two ways, each has its advantages and disadvantages:
First way: ray test. This way works perfect: I can move character up and down of the stairs, but if I have a lot of objects near the pad, and I want to jump I need to do a lot of ray tests.
Second way: move physics body of the character. Using this way I couldn't understand how to move character down of the stairs. Each time it looks like a jump over the stairs.
So what is the correct way to move a character over terrain with different height?
To move a character over a terrain with different heights you should use collisions. To find out more about it, watch a part on collision meshes in Enhancements to SceneKit at WWDC 2015 (time 17:30) and also look at a code in Fox 2 game's sample.
Here's a code's snippet how to use collisions:
private func loadCharacter() {
let scene = SCNScene( named: "Art.scnassets/character/max.scn")!
model = scene.rootNode.childNode( withName: "Max_rootNode", recursively: true)
model.simdPosition = Character.modelOffset
characterNode = SCNNode()
characterNode.name = "character"
characterNode.simdPosition = Character.initialPosition
characterOrientation = SCNNode()
characterNode.addChildNode(characterOrientation)
characterOrientation.addChildNode(model)
let collider = model.childNode(withName: "collider", recursively: true)!
collider.physicsBody?.collisionBitMask = Int(([ .enemy, .trigger, .collectable ] as Bitmask).rawValue)
let (min, max) = model.boundingBox
let collisionCapsuleRadius = CGFloat(max.x - min.x) * CGFloat(0.4)
let collisionCapsuleHeight = CGFloat(max.y - min.y)
let collisionGeometry = SCNCapsule(capRadius: collisionCapsuleRadius, height: collisionCapsuleHeight)
characterCollisionShape = SCNPhysicsShape(geometry: collisionGeometry, options:[.collisionMargin: Character.collisionMargin])
collisionShapeOffsetFromModel = float3(0, Float(collisionCapsuleHeight) * 0.51, 0.0)
}
Edit: I have been able to solve this problem by using PhysicsEditor to make a polygonal physicsbody instead of using SKPhysicsBody(... alphaThreshold: ... )
--
For some reason I'm having trouble with what I'm assuming is SKPhysicBodies being slightly off-place. While using showPhysics my stationary obstacle nodes appear to have their physicbodies in the correct position, however I am able to trigger collisions without actually touching the obstacle. If you look at the image below it shows where I have found the physicsbodies to be off centre, despite showPhysics telling me otherwise. (Note, the player node travels in the middle of these obstacle nodes).
I also thought it would be worth noting that while the player is travelling, its physicbody appears to travel slightly ahead but I figured this is probably normal.
I also use SKPhysicsBody(... alphaThreshold: ... ) to create the physicbodies from .png images.
Cheers.
Edit: Here's how I create the obstacle physicbodies. Once they're added into the worldNode they are left alone until they need to be removed. Apart from that I don't change them in any way.
let obstacleNode = SKSpriteNode(imageNamed: ... )
obstacleNode.position = CGPoint(x: ..., y: ...)
obstacleNode.name = "obstacle"
obstacleNode.physicsBody = SKPhysicsBody(texture: obstacleNode.texture!, alphaThreshold: 0.1, size: CGSize(width: obstacleNode.texture!.size().width, height: obstacleNode.texture!.size().height))
obstacleNode.physicsBody?.affectedByGravity = false
obstacleNode.physicsBody?.isDynamic = false
obstacleNode.physicsBody!.categoryBitMask = CC.wall.rawValue
obstacleNode.physicsBody!.collisionBitMask = CC.player.rawValue
obstacleNode.physicsBody!.contactTestBitMask = CC.player.rawValue
worldNode.addChild(obstacleNode)
The player node is treated the same way, here is how the player moves.
playerNode.physicsBody?.velocity = CGVector(dx: dx, dy: dy)
I'm assuming you aren't showing the exact images that you used to create your SKSpriteNode and SKPhysicsBody instances. Since you are using a texture to define the shape of your SKPhysicsBody you are likely running up against this:
SKPhysicsBody documentation
If you do not want to create your own shapes, you can use SpriteKit to create a shape for you based on the sprite’s texture.
This is easy and convenient but it can sometimes give unexpected results depending on the textures you are using for your sprite. Perhaps try making an explicit mask or using a simple shape to represent your physics body. There are very good examples and guidelines in that documentation.
I would also follow this pattern when you set the properties on your objects:
// safely unwrap and handle failure if it fails
guard let texture = obstacleNode.texture else { return }
// create the physics body
let physicsBody = SKPhysicsBody(texture: texture,
alphaThreshold: 0.1,
size: CGSize(width: texture.size().width,
height: texture.size().height))
// safely set its properties without the need to unwrap an Optional
physicsBody.affectedByGravity = false
// set the rest of the properties
// set the physics body property on the node
obstacleNode.physicsBody = physicsBody
By setting the properties on a concrete instance of SKPhysicsBody and fully unwrapping and testing Optionals you minimize the chances for a run-time crash that may be difficult to debug.
I have a SceneKit game in swift and in it I have a car with a dynamic physics body that is set up like this:
let carScene = SCNScene(named: "art.scnassets/truck.scn")!
let carNode = carScene.rootNode.childNode(withName: "Cube", recursively: true)!
let carPhysicsBody = SCNPhysicsBody(type: .dynamic,shape: SCNPhysicsShape(geometry: SCNBox(width: 5.343, height: 12.125, length: 4.373, chamferRadius: 0)))
carPhysicsBody.mass = 3
carPhysicsBody.friction = 2
carPhysicsBody.contactTestBitMask = 1
carNode.physicsBody = carPhysicsBody
carNode.position = SCNVector3(x: 0, y: 0, z: 5)
carNode.physicsBody?.applyForce(SCNVector3(x: 0, y: 50, z: 0), asImpulse: true)
car = carNode
floorScene.rootNode.addChildNode(car)
The floor's physics looks like this:
As you can see the car gets launched into the air. Then the gravity in the scene makes it fall, and instead of colliding with the floor, it goes right through it.
The gravity looks like this:
What should I change so it will collide with the floor?
I've made a sample macOS playground, available at github.com/heckj/scenekit-physics-playground that shows a physics body interacting. I suspect the core of the problem in your local example is that the floor object doesn't actually have an SCNPhysicsBody associated with it. Until I explicitly set it on SCNFloor (as static), the text blob "fell through" as you originally described.
I recommend adding sceneView.debugOptions = [.showPhysicsShapes] to see the relevant debugging shapes. I've made (and pushed) a few updates to the above repo. Using stock SCNFloor to establish geometry for the physics collection made a tiny target (which is why the slight horizontal impulse made it appear to "pass through"). This last update sets the floor geometry to a long, wide, thin box.
You want to set the floor to be of the type kinematic, not static. With the car being dynamic and the floor being static, the floor isn't interacting with other objects in any fashion, and you explicitly want a collision.
UPDATE: static vs. kinematic doesn't make a difference for the collision interaction, either work effectively the same way, but having a physics body, and verifying it's size or viewing the interaction with .showPhysicsShapes may answer the underlying question of why they're not interacting.
One of posible solutions for u is to set collisionMargin property for your car from 0.0 to probably 0.01, I had the same problem for ball and plane.
I currently have two SKSpriteNodes on top of each other like so (The white part is one and the brown round circle part is the other one):
The white part is positioned 1/3 the way down on top of the round brown sprite node. In the picture, the brown round part has a SKPhysicsBody applied to it already as seen by the light blue outline around it. When I add a SKPhysicsBody around the top ovalish white part it pushes it up and not in the position I wanted it.
How can I have a SKPhysics body coving both bodies of sprites but not have the physics bodies push on one another which makes the white part move upwards? I would like the white part to stay in the position it was in the first image.
Thanks for anyone help!
Here's the code I used for the SKPhysicsBody's:
// create, position, scale & add the round body
roundBody = SKSpriteNode( imageNamed: "roundBody" )
roundBody.position = CGPoint( x: 207, y: 70 )
roundBody.zPosition = 1
roundBody.xScale = 0.3
roundBody.yScale = 0.3
// add sprite node to view
self.addChild( roundBody )
// create, position, scale & add the head
theHead!.position = CGPoint( x: 207, y: roundBody.frame.maxY / 1.15 )
theHead!.zPosition = 2
theHead!.xScale = 0.3
theHead!.yScale = 0.3
// setting up a SKPhysicsBody for the round body
roundBody.physicsBody = SKPhysicsBody( circleOfRadius: roundBody.size.width / 4 )
roundBody.physicsBody!.dynamic = true
roundBody.physicsBody!.affectedByGravity = true
roundBody.physicsBody!.allowsRotation = false
roundBody.physicsBody!.pinned = false
// setting up a SKPhysicsBody for the head
theHead!.physicsBody = SKPhysicsBody(circleOfRadius: theHead!.size.width / 2 )
theHead!.physicsBody!.dynamic = true
theHead!.physicsBody!.affectedByGravity = false
theHead!.physicsBody!.allowsRotation = false
theHead!.physicsBody!.pinned = false
I was able to figure out that if you use SKPhysicsJointPin it does the exact thing I needed! (Which was to basically pin a sprite head on it's body and share a physics body)
let joinTogether = SKPhysicsJointPin.jointWithBodyA(
roundBody.physicsBody!,
bodyB:theHead!.physicsBody!,
anchor: GPointMake(CGRectGetMidX(roundBody.frame),
CGRectGetMinY(theHead!.frame)))
scene!.physicsWorld.addJoint(joint)
Hope this helps someone in the future!
If you never want it to move, set it's .dynamic property to false. Then other objects may or may not bounce/collide with it (depending upon their collisionBitMask) but it won't move in response to those collisions.
Your own answer is correct and a better solution but just to explain further.
The reason of the bodies colliding is that by default a physics body's collision bit mask is set to all categories which means it will collide with everything. In your code you are not calling
roundBody.physicsBody?.collisionBitMask = ...
which is why its using the default values.
To change that you could give your body and head a different collisionBitMask.
Im sure you will deal with this sooner or later when you handle collisions
Also as a tip it's a better idea to not force unwrap the physics bodies unless you have too, even though you know they exist. So you should replace your ! with ? whenever possible.