Is there any way how to pause rendering in Sprite Kit runloop, but still simulate physics and run all actions?
I'm writing small simulator and I need to be able to check collisions and apply forces to objects so I think it would be great to use the new Sprite Kit physics. However I have to be able to turn off rendering and focus just on simulation, but I am not sure if this is possible with Sprite Kit.
So what do you think, is it possible or do I have to use some other physics engine (Box2D)?
The short answer is no. There is no way to just stop rendering in Sprite Kit. The SKView is responsible for rendering which takes place as the last segment of the scene processing. SKView does have a paused command which causes no actions to be executed but it also stops the physics simulation.
Source: SKView Class Reference
You should use the Box2D engine, as SpriteKit does the same.
The Wikipedia page for Box2D says:
The physics engine used in SpriteKit for iOS and OS X uses Box2D
internally.
Related
I am currently struggling with the following problem:
I am creating a Sprite Kit game in Objective-C, in which I have to use a parallax-animation in all 3 scenes. I use clouds with randomly generated X and Y positions. They appear in the greeting scene, in the game scene and in the highscore scene.
Problem: whenever I switch from one scene to another, I have to restart the parallax-animation, which leads to an messy interruption.
What might be the best strategy to keep the "cloud scene" running all the time in the background, no matter how many times you switch between the game scenes?
Thanks in advance.
For this purpose, consider using only one scene and for each game theme (i.e greeting, game, highscore) use an SKNode which will contain the required elements for its purpose (e.g. the greeting node will have its greeting elements).
This way you can easily keep a "constant" SKNode (i.e. add it once to the scene when the game is first loaded) which will contain your parallax clouds and add/remove required node for the greeting game and highscore when necessary
With Sprite Kit physics I have a simple setup with a ball bouncing inside a rectangular edge shape.
It all works fine, however the ball never comes to rest. The resting property is always NO and I can see that the ball animation keeps making a little bit of movement when it should be resting.
Sprite Kit is based on Box2D and here there is a doSleep option on the physics world, but I cannot find something similar with Sprite Kit.
What am I missing?
You should use restitution. A property for setting the bounciness of the physics body in sprite kit. Actually, it is a property describing how much energy a body retains when it bounces off of another body. Dot operator can be used with the ball's sprite name to access the restitution property.
I am pretty new to making games, but I am pretty familiar with programing iOS. I am creating a shape matching game, so there would be an array of different shapes and the user would drag the shape to the correct corresponding shape if they get it right it would stay and if they get it wrong it would shoot back. Now my question is would that be easier using cocso2d or any game engine or would it be just as easy not using one, just using a touch event?
Since the game you are describing is not graphically intense - I would recommend using UIKit. Couple of reasons why I would use UIKit over cocos2d:
Interface builder / Storyboards are awesome. You can lay out your
screens and game elements on screen. (I know tools exist to do this
using cocos like CocosBuilder, but IMO they just don't compare to
working directly in XCode)
UIKit animations couldn't be easier and you can do some pretty powerful things with minimal code.
You have direct access elements such as UITableView, UICollectionView, UIScrollView, etc. There are cocos nodes that mimic these, but they don't match up in terms of response and behavior.
For more graphically intense games I would still use cocos2d hands down. Some scenarios when you would use it:
You have a large number of sprites with a large number of animations (opengl is fast)
You want to use opengl based effects like particles, lighting, etc.
You need a physics engine
You want to work off a prebuilt game engine (there are tons such as levelsvg, kobold2d, line starter kit, etc)
Hope this helps you.
I've created many types of interfaces using the Cocoa API — some of them using documented basic animation techniques and others simply by experimenting (such as placing an animated .gif inside an NSImage class) — which had somewhat catastrophic consequences. The question I have is what is the correct or the most effective way to create an animated and dynamic GUI so that it runs optimally and properly?
The closest example I can think of that would use a similar type of animation would be something one might see done in flash on any number of interactive websites or interfaces. I'm sure flash can be used in a Cocoa app, although if there is a way to achieve a similar result without re-inventing the wheel, or having to use 3rd party SDKs, I would love to get some input. Keep in mind I'm not just thinking of animation for games, iOS, etc. — I'm most interested in an animated GUI for Mac OS X, and making it 'flow' as one might interact in it.
If u wish to add many graphics animations, then go for OpenGLES based xcode project for iOS. That helps u to reduce performance problem. You can render each of the frames in gif as 2D texture.
I would recommend that you take a look at Core Animation. It is Apples framework for hardware accelerated animations for both OS X and iOS. It's built for making animated GUIs.
You can animate the property changes for things like position, opacity, color, transforms etc and also animate gradients with CAGradientLayer and animate non-rectagunal shapes using CAShapeLayer and a lot of other things.
A good resource to get you started is the Core Animation Programming Guide.
I'm trying to build a weather application on the iPad but it seems that I need some help in animation. Say I'm animating a Radar, so the radar source files have 10 gif/jpeg pictures in 900x700 pixel size. I've tried the UIImage animation technique using the tutorial here:
http://www.icodeblog.com/2009/07/24/iphone-programming-tutorial-animating-a-game-sprite/
but it seems that loading 10 images that big is too much for the iPad to handle and its crashing due to memory warnings. I'm researching other techniques to animate but I can't seem to find something that will do this efficiently.
I've looked at others like Core Animation using sprites, and Cocos2D with sprites. Can someone point in the right direction the best way to animate these big images? (keep in mind that these images are dynamic and changes often so the sprites will have to be recreated on a server and fetched from the iPad to do the animation). Thanks
OpenGL only creates textures with dimensions at powers of 2. In the case of your images, that's 1024x1024, which is a meg of memory per image. Still, that shouldn't be a problem with the iPad.
First, investigate using Xcode's profiling tools to ensure the images aren't being repeatedly loaded into memory at each loop of the animation (likely by way of new objects that aren't sharing cached textures). That could solve your problem from the start.
Second, I recommend using Cocos2D if only for the easy handling of textures and caching. Toss the images into a CCAnimation, pop that into a CCRepeatForever, run it with a CCSequence. When you're done hit CCTextureCache to release unused textures.
Third, lower your animation framerate to 30 or less (if only for this animation). It may be the iPad, but you making a weather app. Not a video game.
Finally, downgrade the size of your image. Justify all you want, but a large radar animation will not sell your app. And just because a website might already be playing that animation beautifully, remember that a desktop has vastly more memory and power than any smart phone.
Try breaking the animation image into into smaller parts and animate those instead by treating each components as sprites. It would be best if you use primarily code (CoreGraphics) and draw your radar "by hand" instead of just using images as if they were animated GIFs.