I created mobile a 3D game using Apple's SceneKit framework. The game heavily depends on physics simulations. Because of that, the physics simulations must be identical across devices. The SceneKit fails to do that as I am experiencing completely different physics simulations across different devices. Because of that, I am looking for a new frameworks or engines to use. Before I dive deeply into libGDX.. How does libGXD handle physics? Will my 3d simulations look identical across devices? If not, what tools do you recommend to use to create identical 3D physics?
First off, due to floating point hardware differences, you will probably never achieve 100% identical physics simulations across different platforms.
Now, Libgdx doesn't have a built in physics engine, but instead has wrappers around the Box2D and the Bullet Physics libraries. Since SceneKit was designed with casual games in mind and cross-platform, deterministic physics probably wasn't considered a top priority, you probably will have better results using the Bullet Physics library.
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For the past year I have been working on an isometric city builder. So far I have not used any framework apart from a loose PureMVC clone.
I have heard of Starling but only recently have I played with it.
From my research, the performance boost is fenomenal, but this forces me to manage my resource a lot tighter.
At the moment, I am exporting building animations one building at a time, in ~16 frames/pngs. These are cropped, resized and exported in Photoshop by a script and then imported in Flash, then exported as a swf, to be loaded / preloaded / postloaded on demand.
The frames are way too big to make a spritesheet with them, per building. I believe its called an atlas.
These pngs are then blited between lock() and unlock(). After the buildings + actors walking around are sorted, that is.
I am unsure if just using starling.Movieclip for the buildings, where instead of loading the pngs, I would build a MovieClip symbol with its frames. So bliting wouldn't even be necessary. Unless adding bliting on top of Starling would improve performance even more. That would allow fatter features such as particles effects, maybe some lighting.
Google isn't offering me a strait answer, thus I am asking here.
Google isn't offering a straight answer because there isn't such. It depends very very much on what you've done, how much knowledge you've got and what are your goals.
Using Starling gives benefits as well as drawbacks. Your idea of resources will change totally. If you really have enormous amount of assets, then putting them into GPU will be really slow process. You must start from there - learn what Starling does, how resources are managed with it and what you need to change in order to make the transition between the two.
If this is not that hard and time consuming task, you will have some performance optimization. BUT again it depends on your current code. Your current code is really important in this situation as if it's perfectly optimized your gain won't be that much (but commonly would still be).
If you need to switch between graphics regularly or you need to have dynamic assets (as images for example) you must keep in mind that uploading to GPU is the slowest part when talking about Starling and Stage3D.
So again, there is not a straight answer. You must think of GPU memory and limit, GPU upload time, as well as assets management. You also need to think of the way your code is built and if you are going to have any impact if you make the switch (if your code heavily depends on the MovieClip like structure, with all that frames and things) - it will be hard for you. One of the toughest things I fought with Stage3D was the UI implementation - there is almost only Feathers UI which will take you a few weeks to get along with.
On the other hand, Starling performs pretty well, especially on mobile devices. I was able to maintain a stable 45fps on a heavy UI app with a lot of dynamic loading content and multiple screens on an old iPhone 4S, which I find great. Latest mobile devices top at 60fps.
It's up to you to decide, but I'll advise you to have some experimental long-lasting project to test with, and then start applying this approach to your regular projects. I've done the dive to use it in a regular very tightened deadline project, and it was a nightmare. Everything worked out great, but I thought I would have a heart attack - the switch is not that easy :)
I would suggest using DMT for rasterizing your vector assets into Straling sprites at runtime, and it'll also keep your DisplayTree! meaning that you'll still have the parent/child relations that you had in your Flash Assets.
DMT will not duplicate assets, and will rasterize the vectors into texture atlases only one time (Cache is saved)
you can find it here: https://github.com/XTDStudios/DMT
I'm making a flash app for AIR. The app is mostly made, but I'm not happy with rendering speed on mobile (render mode - gpu).
I know there is a framework that allows user-friendly way to work with Stage3d called Starling, but I've never used it.
After looking into it and following through some tutorials I've noticed that I need to rename all package flash default classes, e.g flash.display.DisplayObject -> starling.display.DisplayObject.
But such action might be destructive to my code base, plus, I have other frameworks attached that work with some flash package classes.
Is there a way to attach Starling to a complete project without re-naming all the package names, changing assets and re-factoring all frameworks that work with default AIR API?
If you're thinking of switching to Starling, you'll have to redesign your whole rendering code. Starling is no drop-in solution. Just renaming classes in your existing code will not do because it completely replaces flash display list for Direct3D, which does all it's rendering with GPU, with all the differences it brings: bitmapped graphics, texture atlases, careful draw ordering. Learning curve can be a bit steep in the beginning but once you get familiar with basic concepts it's a breeze to work with.
IMHO, it's well worth the effort, especially on mobile. Code that ran in low 10s of FPS in classic display list can easily be made to run at solid 60fps with Starling. Basically, for flash on mobile, Stage3D is the only game in town. And Starling is the best supported and widely accepted framework for 2D stuff on Stage3D, with lots of supporting libraries and a very helpful community of developers.
Go on, take the plunge, you won't regret it.
You can run Starling and a native flash application layer at the same time but it wouldn't give you an optimum experience.
If you want to take full advantage of the gpu acceleration of Stage3d and Starling though it would be preferable to refactor your existing code to use Starling display objects rather than Flash display objects.
You might want to post this question on the Starling forum, they are very helpful guys and it's a thriving developer community! - http://forum.starling-framework.org
What would you say, using canvas or webGL?
I have read somewhere that canvas isn't very performant, because currently it's based on the DOM, or something like that. On the other side webGL isn't well supported yet. And it's also more difficult to learn I guess.
The game is "2.5"D - it doesn't need 3D. But wegGL could make sense for good effects and because it's processed in the graphics card. The fact that it is not well supported across browsers is something I could live with, if I see it really offers advantages (performance, effects, etc.) which I couldn't get using canvas.
I don't mind about steeper learning curve. What is important is that the game is well scalable, performs well at the end, and that most features are potentially possible.
Hope to get some good opinions, thanks in advance!
2D Canvas will do you well here.
The math will be far easier than using WebGL and 2D Canvas is now hardware accelerated on every major desktop browser and enjoys wider support on mobile devices than WebGL.
Canvas is not slow because its a DOM element, ideally the only time you touch the DOM is when you get the context. Touching the DOM, for the record, is always slow but you only have to do it that one time.
There are a few tutorials about isometric canvas games as well as some good questions here on StackOverflow asked by Neurofluxation, but he deleted most of the relevant code from his questions for some reason, which is a bit of a shame.
I can see how this might not be a good enough question but I have just embarked on a journey to build the first decent Game Engine for HTML5 canvas that is cross browser and most of all fast. The only problem is I am very new to game design and don't know many tricks of the trade that will help me.
The game I am currently implementing for which the engine will be taken out of is a tile based 2D platformer with MANY tiles (around 3500). I'll start with some tips that I've thus far learnt.
Redraw Regions - only redraw areas that change
Avoid unnecessary function calls (Firefox does not like too many of them)
Use the DOM if you can
Chunk tiles together for quicker access
Other things I am looking for are things like Terrain Generation, Lighting in 2D, Maps, quick server communication. If this is too vague, I will try and close it. Just want to know game design better.
Links/resources would be good. Especially for physics or important maths.
Only draw stuff that's visible, that means only draw the tiles etc. that are currently on the screen. For tiles that's fairly easy, if you got lots of entities you may either want to use a sliding window to keep a list of screen local objects or use such a thing like a quadtree.
Since there's no easy/fast way to copy one canvas to another, redrawing regions is really complicated, since you can't keep a buffered state of (for example) the background if it hasn't changed. So keeping a list of "dirty rectangles" will be a computational overhead for sure.
The whole topic is very broad, even handling the FPS rate can be quite difficult, this question contains some good links and answers on that topic:
https://gamedev.stackexchange.com/questions/1589/fixed-time-step-vs-variable-time-step
You've also mentioned server communication, if you want to do some multiplayer you'll have to care about even more stuff, you can't trust the client, need to worry about bandwidth, synchronization issues, interpolation on the client etc.
I've done some rather simple 2D games in the past, most of them are not in JavaScript but they should give you some hints:
http://github.com/BonsaiDen/Norum
(Platformer engine demo in C, camera zones, moving platforms)
http://github.com/BonsaiDen/Tuff
(2D Platformer in Java, got never finished, powerups and some cool stuff)
http://github.com/BonsaiDen/NodeGame-Shooter
(2D multiplayer space shooter written in JS, using Node.js for the server and WebSockets for communication)
For some final words I'd say that you should start small, like for example just do a scrolling tile map first, then add a player, then rewrite the whole thing. You want write the perfect engine just from scratch it will take many iterations until you find out all the quirks and tricks.
If you want more precise answers you should open questions on the single components you run into troubles with.
I'm planning to write a diagram editor-style application, where you organize objects on a canvas. This application will need to support setting viewport, zooming, cropping and a lot of other standard features of such a graph style application. I'm looking for toolkits or frameworks which could supports drawing in a standard mathematical coordinate space (0,0 as center point, extendable in all directions), and will scale, crop and zoom this according to (user) commands. Language doesn't really matter, but the more geared it is towards standard GUI applications the better. I would namely like to be able to reuse standard controls and buttons on the canvas if possible.
I think Qt is your friend here. Offers what you need, is multiplatform, quite well-designed and there are bindings for several languages.
From my experience, anything mid-level like C++ with toolboxes - QT, GTK, Windows API etc is horrible for such a work. Not that they can't do it, just that there's 15 lines of obscure code per each simple operation - they are simply not very efficient and more geared towards creating fixed GUI than arbitrary graphics.
This sounds like a good work for Flash, optionally something on top of SVG, maybe even a web app in Javascript.