Hello in a game I'm making using lua in Marmalade Quick,I have run into a problem with the physics.
I have a normal downward y gravity and have some notes that is affected by that.
Now I want to add some objects that "fly" horizontally on the X axis but I can not get it to work.
so one of the notes looks like this:
sky2 = director:createSprite(dw, 40, "textures/tractor.png")
physics:addNode(sky2, {type="dynamic"})
sky2.physics:setGravityScale(0)
my first thought was to
just add the following to an update listener
if(gameplaying == true) then
sky2.x = sky2.x-2.5
unfortunately this does not work after the node has got added physics
then I was looking into using
sky2.physics:applyapplyLinearImpulse or sky2.physics:applyForce
I used it like this
sky2.physics:applyapplyLinearImpulse(-10, 0, -20, 40)
The problem here is that the node then correctly moves along the axis but it is spinnig around (torque effects)..
Is there away to stop this or what am I doing wrong,,
thanks..
Found out that the Marmalade Quick Documentation was wrong, and to not input both a px and a px value but just 0 so sky2.physics:applyapplyLinearImpulse(-10, 0) this will apply the impulse at the centre of mass and make it move straight.
Related
The devforum was no help so I'm asking it here.
Im trying to make a Five Nights At Freddys game and I’m making the custom camera script, but its not facing the correct direction. Why is this happening?
Video:
https://doy2mn9upadnk.cloudfront.net/uploads/default/original/4X/0/2/4/024cca4de534dcfc084a944d3c2a13abf5382e0c.mp4
Code
RunService.RenderStepped:Connect(function()
if PlayerCharacter:WaitForChild("Player"):WaitForChild("isNightGuard").Value and not game.ReplicatedStorage:FindFirstChild("GameData"):FindFirstChild("inCams").Value then
Mouse.TargetFilter = game.Workspace.NightguardPosition
CurrentCamera.CFrame = CFrame.new(game.Workspace.NightguardPosition.CFrame.Position)
CurrentCamera.CFrame = CFrame.new(CurrentCamera.CFrame.Position, Mouse.UnitRay.Direction * 10)
end
end)
The NightguardPosition part is in the correct position and orientation.
I’ve tried many variations of the camera script but they all have the same result, please help?
The issue here is that for the CFrame.new(Vector3: position, Vector3: lookAt) constructor, the second Vector3 is what the CFrame will point at in world-space and is not a direction vector, unless position is (0, 0, 0), the origin. To fix the issue, you must add NightguardPosition.Position to the where the mouse is pointing in the world since that unit ray of the mouse like an offset when having to set lookAt.
Modified code with some comments (changes made to RenderStepped are suggestions and do not need to be built around!):
CurrentCamera.CameraSubject = workspace.NightguardPosition --// The CameraSubject is the LocalPlayer's Humanoid by default, causing some funky movements. Make sure to revert this
--// when cameras are exited.
--// Small performance improvement, unless this is changed elsewhere. Either way, it is best to only set when necessary and not in a looping behavior.
Mouse.TargetFilter = game.Workspace.NightguardPosition
local nightGuardPos = workspace.NightguardPosition.Position
RunService.RenderStepped:Connect(function()
--// CurrentCamera.CFrame = CFrame.new(game.Workspace.NightguardPosition.CFrame.Position)
--// Can be removed as this is the same as getting the Position of NightguardPosition
CurrentCamera.CFrame = CFrame.new(nightGuardPos, nightGuardPos + Mouse.UnitRay.Direction * 10)
end)
Say we have scene with spring field node at the (0;0) and some node affected by this field.
Weird thing: if we put node at (0;0), it flies away immediately with huge speed; if put at some offset, like (0;10), it moves toward field node, oscillates for some time before stay at (0;0) and then flies away. Is there any way to prevent this?
Turned out this only appears in iOS 8.
Problem lurks in calculation of force multiplier. If we set falloff = 0 or min radius = 0, such behaviour doesn't appear. So setting minRadius to 0 solved the problem. Thanks #0x141E for support.
Upd:
I was wrong - setting minRadius doesn't solve the problem. I didn't noticed that field coordinates displayed as (0;0) in Scene Editor in a fact were non-zero, delta was about 1*10^-4, while node was placed exactly at (0;0). Such quite small initial distance seems to help, but can't say what will happen if node eventually stay at the centre of the field.
For this time solution is to add initial distance and wait for end of iOS 8 support for app.
I have found a few other questions and answers similar to this, but none of them quite work perfect for me.
My vision is to have a horizontal scrollable view at the bottom of the screen where I can scroll through what will look like cards in a hand. Ideally, I could eventually make the card in the middle scaled up a bit and give it a highlighted look to show the user which card is selected. Even better would be if I could figure out how to keep the scroll view resizing to fir the number of sprites (cards) in the view.
Anyways, I am still very new to XCode and Swift, so it is hard for me to take what I find and change it. But, I am hoping to learn fast.
What I understand so far is that a UIScrollView could overlay the scene and with a moveable spritenode I could scroll through the view. The view would then translate the coordinates somehow to the SpriteKit Scene to move the sprites that will look like they are in the view. I think that's how it works. Any help would be great. I am pretty stuck. <3
You have to make your own logic that takes place in touchesMoved() using a global/member variable.
Unfortunately, a lot of gamedev and SK is math and logic.. You have to come up with your own problems and solutions.. There is no manual because the possibilities in programming and Swift are endless :)
Moving the cards:
Basically, you compare each touch location to the last one, and this becomes a "delta value" that you can use to perform actions.
Example, if I touch in the center of the screen, my touch location is 0,0 (or whatever your anchorpoint is set to). If I move my finger right, then I'm now at say 25, 0... This creates a "delta value" of +25x.
With that delta value, you can perform various actions such as moveBy for all the cards... so if I have a deltaX of +25, then I need to move all of the card nodes to the right (by a certain amount that you will determine according to your preferences). If I have a deltaX of -25, I move the cards to the left by a certain amount.
Where you do the actual moving is up to you--you could put a function in update() or touchesMoved() that constantly moves the cards a certain direction at a certain rate of that deltaX value..
Ok that was a mouthful... Maybe this will help:
for touch in touches {
myGlobalDeltaX = myDeltaXFunc(currentTouch: touch)
myMoveFunc(cards: allTheCards, byDeltaX: myGlobalDeltaX)
- You can search on how to make a Delta function, but it really is just the same thing from Algebra.
- myMoveFunc can be something as simple as iterating through all of your card nodes then running .moveBy on them at the same time.
Middle detection:
To detect which card is in the center, you would put in touchesEnded() or update() a call to check the name / identity of the node in the center of the screen... so something like
// `self` here refers to your GameScene class' instance, which is just an `SKScene` object
let centerX = self.frame.midX
let centerY = self.frame.midY
let center = CGPoint(x: centerX, y: centerY)
let centerNode = self.nodes(at: center)
You would obviously want to change centerX and centerY to wherever it is you want the middle card to be :) Right now, this is just in the dead-center of the screen.
Once you have a centerNode, you would then just need to do whatever function you have created to "select" it.
let selectedCard = centerNode
mySelectionFunc(middleCard: selectedCard)
This may look like a lot, but I drew out the steps to make understanding it a bit easier.. You can do all of this in one line if desired.
mySelectionFunc(middleCard: self.nodes(at: CGPoint(x: self.frame.x, y: self.frame.y)))
Hope this helps some!
I've been looking at Figure 7-3 in this sprite kit documentation: https://developer.apple.com/library/ios/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Actions/Actions.html but it has left me pretty confused. They seem to give the same name to multiple things e.g., camera/character.
I am in the default SKScene, MyScene class. In initWithSize, I create a SKNode *myWorld, just like the documentation suggests. I then have a series of methods that add my background images to myWorld. Scrolling that works just fine, but what I want to do is stop the vertical scrolling when the bottom of the images in myWorld reach the bottom of the scene. For the life of me, I cannot figure out how to refer to the bottom of myWorld. For the bottom of the scene, I simply do
CGPoint sceneFarBottomSide = CGPointMake(0, -self.size.height/2);
where self.anhorPoint is set to [0.5, 0.5].
How do I refer to the bottom of myWorld?
The edge of myWorld is whatever you set it to be. In other words, myWorld is a node which isn't itself a view or a sprite. It's simply an object that contains sprite or shape children (for example, SKSpriteNodes or SKShapeNodes). When you are adding your sprites to myWorld, keep track of their position. Then use their position to define the "size" of myWorld. You can use this size information along with myWorld.position to know when the (bottom) edge of myWorld is coming up.
It ended up being extraordinarily easy to resolve. Thanks Andrey for pointing me to that Apple documentation on the Adventure game, that's what really tipped me off and cleared up some of my understanding. Here's the few lines of code to get the behavior I desired:
// Move world
if (monkeyPosition.y > 0 && monkeyPosition.x > 0) {
[myWorld setPosition:CGPointMake(-monkeyPosition.x, -monkeyPosition.y)];
} else if (monkeyPosition.y > 0 && monkeyPosition.x < 0) {
[myWorld setPosition:CGPointMake(0, -monkeyPosition.y)];
}
I referred to following article. What I actually need to draw is concentric/ Concrete circles with an effect as shown in image below.
I am finding it difficult to a) Draw the white streaks radially b) Find some key terms to search for related articles to proceed further on this.
Any hint or link to read about this will be of great help.
Try these
Metallic Knob
Metallic Knob 2
http://maniacdev.com/2012/06/ios-source-code-example-making-reflective-metallic-buttons-like-the-music-app
This is a tutorial on making reflective metal buttons. You can apply the techniques from the source code to whatever object you're trying to make. The source code is found here on github. I just googled "ios objective c metal effect" because that's what you're trying to do, right? The metal effect appears in concentric circles and changes as you tilt your phone, just as the iOS6 music slider does.
I don't have any code for you but the idea is actually quite simple. You're drawing a number of lines radiating from a single, central point (say 50,50) to four different sets of points. First set is for x = 0 to 100, y = 0. Second set is for y = 0 to 100, x = 0. Third set is for x = 0 to 100, y = 100. Fourth set is for y = 0 to 100, x = 100. And for each step you need to either change the colour from white to black or white to grey in increments or use a look up table with your colour values in it.