I was just wondering if there is a way to implement a linear interpolation effect on my SKCameraNode while it is following my player node through use of SKConstraints. I am currently using constraints identical to the constraints used in Apple's Demo Bots tutorial. The alternative seems to be either using actions to reposition my camera with a delay/time, or changing the position with a delay directly in the update method. The camera scrolling as it is seems kind of jerky while the distance constraint to the player is set to a constant 0.0 like it is in Demo Bots. Please let me know your thoughts and all feedback is appreciated.
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The gear joint in Box2d is great, but I don't know how to implement that in Sprite Kit. Is there any solutions to implement the gear joint in Sprite Kit?
Thanks.
Here are the available Sprite-Kit joints :https://developer.apple.com/reference/spritekit/skphysicsjoint
As far as I can understand, there does not appear to be a direct correlation to Box2D's gear joint, which seems to make one body rotate when another body is rotated.
In that case, you might want to investigate overriding the didSimulatePhysics or didFinishUpdate methods to manually set the rotation of one object based upon the rotation of another object:
https://developer.apple.com/reference/spritekit/skscene/1519965-didsimulatephysics
https://developer.apple.com/reference/spritekit/skscene/1520269-didfinishupdate
It might be as simple as:
wheel2.zRotation = wheel1.zRotation
but if the gears have different numbers of teeth (thus different ratios), you'll have to do some calculations.
I have allowsCameraControl property set to true. I need my camera to tell me what it's position and rotation is, while I move it around with pinch and pan gestures so I can later update my camera to that position. Is there some function that is called every rendering moment so I can put println: statement in it? The other option I could think was to set a didSet statement at camera's position and rotation property but I have no idea how to do that if I'm not the one defining the property in the first place.
Found a way around it using custom buttons(moveLeft,moveRight,rotateLeft etc..) to move the camera(and report current position) around 3D space. Works great. Can't tell if mnuages's suggestion works, but it looks allright.
you can use delegation methods such as SCNSceneRendererDelegate's -renderer:didRenderScene:atTime: and you can access the "free" camera by using the view's pointOfView.
I'm trying to recreate the barrel effect that can be seen on the camera mode picker below:
(source: androidnova.org)
Do I have to use OpenGL in order to achieve this effect? What is the best approach?
I found a great library on GitHub that can be used to achieve this effect (https://github.com/Ciechan/BCMeshTransformView), but unfortunately it doesn't support animation and is therefore not usable.
I bet Apple used CGMeshTransform. It's just like BCMeshTransform, except it is a private API and fully integrates with Core Graphics. BCMeshTransformView was born when a developer discovered this.
The only easy option I see is:
Use CALayer.transform, which is a CATransform3D. You can use this to simulate the barrel effect you want by adjusting the z position and y rotation of each item on the barrel. Also add a semitransparent dark gradient (CAGradientLayer) to the wheel to simulate the effect of choices getting darker towards the edges. This will be simple to do, but won't look as smooth and realistic as an actual 3D barrel. Maybe it will look good enough to create a convincing illusion though? (To enable 3D transforms, you need to enable depth by using view.layer.transform.m34 = 1/500.f or similar)
http://www.thinkandbuild.it/introduction-to-3d-drawing-in-core-animation-part-1/
The hardest option is using a custom OpenGL view that makes a barrel shape and applies your contents on top of it as a texture. I would expect that you run into most of the complexities behind creating BCMeshTransformView, and have difficulty supporting animations just like BCMeshTransformView did.
You may still be able to use BCMeshTransformView though. BCMeshTransformView is slow at processing content animations such as color changes, but is very fast at processing geometry changes. So you could use it to do a barrel effect, as long as you define the barrel effect entirely in terms of mesh geometry changes (instead of as content changes like using a scroll view or adjusting subview positions). You would need to do gesture handling + scrolling yourself instead of using UIScrollView though, which is tricky and tedious to get right.
Considering the options, I would want to fudge it by using 3D transforms, then move to other options only if I can't create a convincing illusion using 3D transforms.
I have a SpriteKit Scene in which I want to have the effect as if a camera zoom and scale. Does anyone know of any libraries or some easy methods of doing this?
It was very easy to do in other 2D engines but does not seem simple.
I was thinking of doing it from the app delegate, and using the window to zoom since my character does stay around the same position.
The desired effect I would like to accomplish is like that of the start of an Angry Bird level when the camera pans into the level and then the launch doc.
http://www.youtube.com/watch?v=_iQbZ3KNGWQ This is an example of the camera zoom and pans I am talking about.
Thanks for the help.
If you add an SKNode to the SKScene, and make your scene content children of that node instead of direct children of the scene, then you can zoom and pan all of the contained content just by adjusting the xScale, yScale and position properties of the added node. (Any content you did not want scrolled e.g. scores or whatever could then be added to a different SKNode or added directly to the scene).
The adjustment could be done by overriding one of update:, didEvaluateActions, or didSimulatePhysics in your SKScene subclass. The choice would depend on if you are just moving your character around by yourself in update:, or if it also gets moved around by running SKActions or by simulated physics.
I've been exploring iOS animations and I'm trying to find out if there is a simple way to restrict animation movement to within a certain area. For example, lets say you are using a pan gesture recognizer to drag a UIView around the screen. Is there a simple way to enforce that the frame of the UIView does not move beyond a specified location?
The way i've currently been approaching it is to take the UIView, calculate the location of the edges, and within my handlePan method, simply return (ie don't adjust the center point) if the frame is touching the boundary. Is there a more elegant way to do this? Even if only along a single axis?
Thanks!
I actually am doing that in one project and basically well, I am using the "non elegant" way. I have a set of coordinates "boundaries" from which the view I am dragging should not pass. Although there better ways to do this than others. For instance for a smoother experience:
Compare the X axis independently for the Y axis. What I was doing in the beginning was to compare the X and the Y in the same if sentence.
Extra: Check this project to get some ideas.