iSDGE (an Open Source iPhone Game Engine)

Hey,
About two weeks ago, I checked out the only two free 3D game engines for the iPhone: Oolong and Sio2. While they have quite a few nice features I actually gave up on Sio2 when trying to have a camera moving around a point and loading and destroying single objects into an already loaded level and on Oolong even before rendering anything except the nice examples.
So, as both was too complicated for me I decided to make it easier and write an engine myself.
It is still at a very early stage, but till now very well progressing.
It is far not optimized yet and just a graphics engine for now and I have some doubts about my design (which works well so far and will most probably stay similar, it just isn´t perfect yet ;)).
However, what it supports so far is rendering with OpenGL ES 1.1 and OpenGL ES 2.0. It is possible to load .3ds files, set all kind of material parameters and has an in my opinion good shader system.
For textures .png and .jpg is supported and it is possible to display textures as 2D objects as well as rendering text from bitmap fonts.
So far only 8 lights are supported and there isn´t any scene management yet.
The next features I will implement are animations and object specific functions, so that it is hopefully usable for a first simple game this weekend, I am going to create .



The second image is rendered with my iphones emulated fixed function pipeline, while the third is rendered with my own default shader. As you see, there is still something wrong with the ambient term (Edit: I found some global multiplicator in the fixed function pipeline which I just disabled as it doesn´t fit into my system and it looks exactly the same with both OpenGl Version now :)). The third on the other hand also shows a custom shader, as one can easily see on the green color, which changes over time. The one frame fps difference btw doesn´t mean anything as it of course runs stable at 59-60fps.

I am trying to keep Source Forge up to date with the projects state here: http://isdge.sf.net

Brillo. I hope this goes far, mate. If I find myself itching to do some iPhone stuff (which I'm sure I will in the near future) I'll be very keen to try it out.

Jibb

Wow! Great! Surprise, surprise! I'm very curious to see the further results!

Seconed. Open source sounds great!
Looking forward to seeing your first game.

sounds interesting. i am looking forward to your further progress too. will the api be similar to gamestudio?

edit: what physics engine will you use or how will you do collision detection?

Maybe, even simpler? But, you are right, this way our knowledge of Lite-C gets a purpose beyond the mere Windows platform.

Great !
And Iphone 3D game must be optimized, so you won't do spectacular 3D like Next Gen !
If the engine can manage collisions, animations ,particles and
HUD it would be great , caus free.

It is easy to develop on it ?

Will it only work on Mac OS X ?

I like your engine. 'nuff said.

PS: Yep rei, it only works on OS X.

I guess you already tested it, right?

Thanks for your interest
The api will really get a bit similar to gamestudios, with smaller and bigger differences. Which means that I will create something like those events in unity or also shiva and probably many other engines, as that is easy to create and works well to set and update entity behaviour.
You currently there is only an object class, which is just for the rendering and will be part of an entity class later on, but to create a new one, you just have to call any objects createObject(filename) function and it will return you a new object, which is freed auomatically if you don´t destroy it calling destroy before game exit. The position can be changed by changing the position elements x, y and z values and so on. An object consists of one or more meshs and a material for each mesh. A mesh is just a collection of vertices and is usually loaded from a model file. A material has all kind of parameters, can handle one or more textures and can have a shader. Shaders are provided with the material data if you use the predefined variable names in a shader. Materials also allow to register custom variables for a shader, which you have to allocate yourself, but will be freed automatically.
Textures and shaders are shared between materials and materials and meshs are shared between objects, but especially materials can of course be cloned.
For 2D, there is a panel class, which is basicly just a container with addImage and addText functions, so that the images and text objects are rendered in the order they were created (I will also add some functionality to change the order of course).
As the .3ds file format doesn´t really seem to support bones animations, I am currently writing some collada importer. Very minimalistic for now, but it is most probably going to be the file format for everything.

The whole stuff is written in Objective-C++, I am trying to keep the Objective part out, but did some mistakes, which shouldn´t be very hard to correct and which I most probably will correct in the future, even though I doubt that the engine will be used for another platform than the iphone, I want to keep the possibility open and basicly have some wrappers around the iphone specific stuff. That means that many parts are platform independant, or at least as far as OpenGl ES is platform independant, but for iPhone dev you need a mac in any case, and at the current state of the engine anyways.

Is android too different?


Is bones animation really important, it requires quite a lot of performance(doesn't it?), and a few years ago vertex animation was sufficiant for pc, too.

I am not sure about the different mobile platforms and as long as they use opengl for rendering and offer a possibility to compile c++ code for them, big parts of my "engine" should work with them, after some small adjustements, as I wrote before. The only bigger (also not really) problem would be my xml parsing.

My internet is slow, so that already is a reason to use bone animation instead of vertex animations. But as the polygon count is very restricted, that most probably wouldn´t be a problem, but also means that bone animations aren´t much behind in terms of performence.
For now I want bones, but I may add a possibility for vertex animations as well, if bones turn out to not be very suited.

Yesterday I worked the whole day on trying to import a collada file and gave up on loading the texcoords correctly somewhen today...
I now wrote a converter using assimp to an own xml based format. That means, that I will provide a simple command line tool to convert all kind of file formats to the one of my engine.
It also doesn´t have animations yet, but converting files and loading them already works well. I will now go on with the animation part finally .

Didn´t really got a game yet, but at least there is an entity system with some kind of actions now as well as a raytrace function. Touches are also handeled correctly now, which wasn´t the case before. Animation can be converted to my own model format and can also be loaded. They just can´t be played yet due to some mistake in my math functions, I think (I am messing around with right and left handed coordinate systems, z and y up, row and column major matrices due to the differences between assimp, examples from the internet and my engine/opengl and that is just driving me crazy :P).
What you can see on the screenshot above are about 30 entities with each about 100 triangles. And as I wrote before, rendering is very unoptimized and I am optimistic that it is possible to get this running at 60fps again.

is this all in objective-c? any chance for an android port?

Most parts are written in C++, the only xcode specific stuff I stupidly used everywhere is the #import semantic instead of include. The only Objective-C code is my view class, which is anyways very os specific (on windows, that is the part of creating the window and initializing the draw surface and handling events like touches on the iphone). There are also a few lines of objective-c to get the path of a file on the device and the whole file parsing uses an objective-c specific xml parser, but that should may be changed to tinyxml (only thing keeping me away from doing so is its licence, as it is a bit more restricted than MIT, even though I should may anyways change to that license as well...) or something.
So it should be doable without many problems, but I don´t own an android phone and I also have no experience with developing for it .

Edit 1: I just had a quick look at the android website and found out that it only supports OpenGL ES 1.0 and only partly 1.1, which could mean that one also has to write another renderer, as so far I have only something for OpenGL ES 1.1 and 2.0. But that also shouldn´t be hard.

Edit 2: Not completely right There is also the NDK, which other than the SDK doesn´t have to be written in java, which would have been another problem, but which only supports OpenGL ES 1.1 and 2.0, so that it would fit again. But as you see, I am not into android at all.

can opengl es also be used for windows applications? or is it only available for mobile devices? it kind of seems to be a smaller, cleaned up opengl so i could imagine that it is nicer to work with. just curious...

I asked that myself before as well, but it seems as if the only way to use it on windows are wrappers around OpenGL.

Can't wait to see further results on this!
I hope you are still in a flow of never ending motivation!

I finally got everything working again with rewritten vector, matrix and quaternion classes, even though there is still something strange with the coordinatesystem...
The rest of the evening will go into comments for Doxygen.

Wohoow!

A first documentation is online. Nothing great yet, but at least a lot better than nothing in my opinion: http://isdge.sourceforge.net/doc/
I also adjusted the projects website a bit, but it is still very ugly: http://isdge.sourceforge.net/
I basicly just wanted to put a link to the documentation somewhere .

There is no software, just a couple of sourcecode files... The documentation documents the code. And the code can be downloaded via svn. So please stop posting about things you´ve got no idea from.

-dead-
Sure, I have to get flamed in every post. Thank you Quadraxas.

Cowabanga: just stop making comments about stuff you have no idea about... please. (<- so this sentence is flaming.)

There is no software, you have to dowload to sourcecode to your MAC, check the examples and then study them and then build your game from source.

edit: i do not want to side-track the topic, this argument is over.

I added support for multiple cameras and "converted" the xml parser to c++, as well as already a couple of the other files. As soon as everything compiles with C++, I will add Support for Android and depending on how well that worked out also for Symbian and that other system Nokia seems to use, which are both included within one SDK.

As I like such stuff, I added a simple possibility to switch on cross view stereo for the example project. But I have to admit that the monitor is a bit too small

*cheering*
Can't wait for support for Android!

I now implemented VBOs which speeds up rendering a lot and am now working on implementing multisampling. Well, I already got it to work, but it is currently just some kind of ugly hack



Edit: I think it is actually just 1x MSAA, thanks to a typo in my code . However, MSAA is implemented now and meant to work perfectly fine .

The engine is now able to render cameras and panels into textures (without MSAA, which might be possible, but for now I decided to not implement it). This also allows for postprocessing.
So here is some bad red-cyan anaglyph:

What about some interaction!

Come on, they are... ROTATING
I plan to add bullet for the physics, but before the graphics part has to be kinda comlete.
And well, this is meant to be a simple example level on how to get things running without anything more complex than needed.
You can already code whatever interaction you want, but this hasn´t much to do with the engine.
This is just about the engine and not about game mechanics

The next feature will probably be stencil shadows.

stencil shadows?

nobody seems to like and use them anymore. for example i think i recently have read a tweet by steve streeting where he whined a bit about them and that they make ogre unnecessarily complicated and inflexible but he still has to keep them in for a while because of backwards compatibility.

but maybe they are still useful for very low poly iphone games?

can this be done on A7?

Yeah, check this thread: http://www.opserver.de/ubb7/ubbthreads.p...amp;Search=true

To me, they seem to be the best approach for realtime shadows on the current hardware. I am still doing some research on them, but it looks as if the iPhone SDK provides some extensions to simplify their usage and make them more lightweight.
But I am still trying to understand, how to implement them in the best way possible and didn´t write any code yet . So I might change my opinion about them being lightweight and drop the idea to implement them.


Yes, you can find some code for it on my blog.

thanks

Anyway, it would be nice to see a small tutorial about making a small game with your engine. Things like such a tutorial are giving a boost of feedback!
Maybe, JustSid is interested to help you with this!

Did you already mention how to import a model into your engine?
Most appreciated: a way from blender to iSDGE.

I finally wrote an exporter for blender to directly export a selected object to my engines custom file format. "Only" thing missing for the exporter are animations, which aren´t exported yet.

I btw put the engine on Indie DB: http://www.indiedb.com/engines/isdge


I have no idea what I did there, but so far all models exported with it worked fine . It also supports several textures per object.

That's a great progress!
What's your recommended size of model and skin?

I can only guess, but the maximum size is 2048x2048 (iPhone 3GS, iPhone 4, iPod touch 3rd gen) and 1024x1024 (iPhone Classic, iPhone 3G, iPod Touch 1st gen, iPod Touch 2nd gen).

Well, the iPod Touch 1st gen and the iPhone classic aren't supported anymore, but it's better to use 1024x1024 as maximum (or increase the size of the binary and use 2048x2048 for the 3GS and iPhone 4).
Best should be to use as less textures as possible, texture switching is a expensive process and kill your framerate really fast. So you better go with a 1024x1024 skin instead of two 512x1512 skins.

However, those are my experiences with my engine (which is just 2D), so maybe Slin has made other experiences.

What do you mean? Number of tris and resolution?
Both as small as possible without destroying the look .
For medium important stuff I´d say around 500 tris and a resolution of 256*256. If you are talking about the scale, 1 unit = 1m does probably do a good job. Float should give enough precision than for small and for big objects, as long as you don´t have distances of lightyears or something .

If you´ve got any ideas for features, feel free to request them here: http://sourceforge.net/tracker/?group_id=318519&atid=1339401 (needs a sourceforge account, to add stuff)

I meant the number of tris and resolution. Thanks.

I have to think about what I would like to see next.
Will need some time to get familiar with sourceforge, too.

I finally got some first stencil shadows to work. They don´t yet work with more complex objects due to the kind of normals the shadows need, but that is going to be easy to fix. A bigger problem is, that my silouette detection is quite slow at the moment. There is space to optimize it, but I am not sure if that is going to be enough.
However, here is a first screenshot:


Fixed the normal "problem":


and some house I´ve thrown together in blender (shows pretty well, that things are slow at the moment^):

I guess that 1GHz will be too less anyway to make reasonable framerates in games for smartphones.
More appropriate is probably a safe decal shadow sprite which sticks to the surfaces.
But, nonetheless, any progress in this project is welcomed!

Well, Doom 3 worked well with my 800MHz CPU and relied heavily on stencil shadows. I am pretty sure that it can still be optimized a lot. It is just well posible that my current approach while being very easy, is most probably also the slowest one .

Okay, then go on with implementing fast animation routines!
(But, you already know my even deeper feature wishes. )

I came up with an idea to precalculate the slower parts of the silouette detection, which basicly works the same way as before but A LOT faster. It is quite memory consuming, but I doubt that this will ever be a problem. That precalculation is kinda slow, but only has to be done once and is independant of light and model positions and orientations.
The spacecraft on the following screenshot was running with about 0.1fps with shadows before, so I´d say that this is a big improvement (the scene should have about 2.5k triangles, maybe a bit more):


And another one (silouette detection is really fast, but rendering of the volume needs some speed up):


And one more

Looks quite nice, but still, you can only develop on a mac, can't you?

Inspired by the epic citadel demo, I just created a small sample project for iSDGE presenting a basic reflection.

The render to texture is quite slow for some strange reason I don´t understand, but I hope to find a solution...

do you currently working only on the iOS version? or do you develop the Android version parallely? or will you port it afterwards?
(Asking, just got new Android phone )

I'm going to buy an Android phone too, and there doesn't seem to be a good free 3d engine around yet, so it might be a great possible market.
Are you working on it?

I actually just started looking into android a bit more today. The initial setup is a bit tricky, but it seems as if I got it to work now, but that is unhappily something everyone has to figure out themselves. I am also not sure about compiling on windows as you will need cygwin for it which could be a bit tricky to set up as well. So it is probably more fun to develop on linux or mac for android when using my engine. The reason for this is the way through c++ using, which should give many advantages in terms of speed and functionality, but doesn´t simplify the pipeline. It would be easier to just go with Java, instead of this combination of c++ compiled to a lib which is then used through the android java sdk. However, this is something you have to figure out once and which shouldn´t make any more problems afterwards.
I am now trying to get the android ndk examples to work in the emulator and will then go on with implementing animations into iSDGE. After that I hopefully manage to port the whole thing to android and then I have to figure out a way to get an android phone for free .

Still no android and no animation support, but animations are on a kinda good way and I implemented some kind of basic terrain.


I actually also uploaded some video of the shadows on youtube: http://www.youtube.com/watch?v=Chl_s70AAgU
Both is quite a bit faster on the real device...

Keep it on! Animations, please!

I implemented some basic culling and added water to my terrain testscene as well as hardcoded fog (within the terrain shader). The terrain shown uses chunking and in total has 512*512 vertices.

Very nice!

I added some kind of LOD for the terrain and reflections for the water.
You can see it in action on youtube: http://www.youtube.com/watch?v=BlZGAGVJGAo
But please read the description .

More complex scenes will hopefully follow soon, but to at least show some progress:
I rewrote the blender exporter which now also supports a second uv set and vertex colors.

Very pretty

With the help of Superku (who provided a very helpfull matrix and motivation), I finally got some kind of solid view frustum culling to work:

Not pretty and at the time of the screenshot (with 500 entities) I even had doubts that the culling would cause any peroformance gain at all. But when starting at the center looking to the outside, I have stable 60fps with culling and only 23fps without culling, so it actually seems to bring some performance gain, even quite a lot

@Slin : great , you are reaaly skilled !
Conitec should hire you as programmer, i'm sure we would see lot of things in Forecast and Betas with you on the engine

Yesterday I implemented a basic particle system which happily works very well so far.
Not very good looking, but at least a screenshot:

I implemented tangents and wrote a basic tangent space spec bump normalmapping shader:


and I put together a basic solar system app, just for fun (the scaling is correct, the distances are not on this screenshot, as one would hardly see any planet then (it is already very hard to find the earth, the way it is on the screenshot)):

Oh, you're making good progress

Looks very interesting! How many hours are you already working on it?

I´ve got no idea.
I would guess something between 100 and 1000, probably closer to 1000 than to 100
There have been many days without me doing anything on it, but there are also some days at which I am working on it for 15h or something, so it is really hard to say

We just started a first big game project with it, which so far seems to be progressing very well and especially helps to fix bugs and adds new needed features and hopefully animations somewhen... (they would probably be already there if I hadn´t first to export them from within blender :P)

A year back or so I looked a bit deeper into DirectX 9. I bought a good tutorial and worked through it just for fun (not for a project or so). It was great fun, but when it came to bones animation the fun turned into a nightmare ^^ A lot of recursive functions and difficult matrix transformations...

I wish you a lot of fun with those

when i wrote the mdl7 blender exporter i couldn't get bone animations to work either. the matrix stuff almost drove me insane.

but then after a pause of some weeks i tried it from the other side. i wrote a simple opengl mdl7 viewer (in python) and after some trial and error i got the bone animations to work. then i knew how the matrices had to be contructed.

Oh boy, I wish you would write a binary model loader and exporter right now. I don't want to wait for forever just to check if everything works now.

Edit: Well, I want to show a screenshot too:

Okay, Nils almost punched me to death for last screenshot, so I promised him to post a better one.
Before you say "oh, the particle effect looks horrible", thats Nils fault!


Oh and btw, the screenshot is not staged but actual footage from a game.

Still very WIP, but so far the engine needed nearly no changes and additions (the biggest part was fixing some methods of my quaternion class to get the turning and camera to work correctly)

Looks very cool, including the planet shader, and the sun looks way better now!

Very nice indeed... I left this forum for a couple of days and... Doh, look what I've missed(this). An open source Iphone 3d engine, too good to be true, but it's true
Nice work ,Slin, as always

Well really good progress
I plan to buy a Mac to be able to build Iphone games.
I'll have to try yuour engine, what it misses is all tools
like level editor.
For now, in the NOT FREE domain i just see Shiva 3D or Unity that have the tools around the engine.
Torque is for 2D games on iphone for now only !


Keep it up !

You are free to write your own tools like Slin and I did, it gives you much more power than using something existing and its a good way to increase your Cocoa skills.
And I wouldn't recommend starting with a game, start with a simple UIKit project and learn the whole UIKit lifecycle, then head over to games and engines. Why? Simple, the engine might be very powerful (I'm running out of memory before the engine runs out of FPS), but the iOS binding is really horrible, although Slin already improved it alot.

So, learn the basics on how to write a great app with UIKit/Cocoa-Touch and then learn how to write great apps with eg. isdge.

Today I made a basic implementation for bullet rigid body physics, which so far seems to work great. Nothing too great looking, but because I can, I at least turned on stencil shadows and multisampling for this screenshot:

I plan to upload a video in the next days showing it in action, just to add another iphone physics video to the 1 mio others or whatever the number is

Well, ugly and everything, but at least something at all:
http://www.youtube.com/watch?v=O0a2udK6Uas

Graphics same as on GS Looks good..

AND some more physics

prrrty.

After a long time a little update:
I ported iSDGE to Linux and Windows and it now also runs on Android including Ouya.
I also implemented skeletal animation and support for 32bit indices.
What is still missing is some clever scene management, also the general design is quite suboptimal in many cases, but other than that everything works pretty good and quite fast .

http://www.youtube.com/watch?v=aPCk1WEUN8k

Any chance we can have look on the source?
For studying purposes

it´s on github: https://github.com/Slin/iSDGE