I took a look at Anton's demo on a G1 device, and I was glad to see the integration of accelerometer as it really added value. I assume the calculations for collision detection and response are fairly basic, which allows for that performance.
Simpull will also provide good performance for a scene of that nature (all verlet, no joints). At least I believe it will. The point where simpull becomes slow is when a more complex scene is in play with 10s of objects with many joints connecting some of them. Since the engine is all verlet and no rigid body dynamics, joints are one way to acheive a similar result, but with a very bad performance hit due to all the new temporary objects and new calculations. I would be super impressed to see a demo like Anton's with rigid body dynamics involved with at least some rectangles, if not other polygons and perhaps a joint or two. That is where the performance degrades quickly in my experience. On Apr 1, 2:45 pm, mscwd01 <mscw...@gmail.com> wrote: > Thanks Lajos for pointing APE out, I hadn't heard of it until now. > > Unfortunately your link to your Android port is broken, can you mend > it as I dont fancy spending another hour porting another library to > Android :D > > Thanks > > On Mar 31, 9:50 pm, lkelemen <tridc...@gmail.com> wrote: > > > > > Hello everyone, > > > I was also disappointed with jbox2d's performance so I checked APE > > (Actionscript Physics Engine) fromhttp://www.cove.org/ape/. > > It was converted to java (http://www.cove.org/ape/java_ape.zip) so I > > started to convert the java version to Android. > > > The performance is quite OK for 10-20 objects at the first start of > > the app but if you exit with the back key and restart it form the > > installed copy > > (either in the emulator or on the dev phone) then it gets slower and > > slower with each start. If you restart it from the emulator (by > > reinstalling it) then it is faster again. > > Neither the pressed keys are not working (probably it is because of my > > poor Android programming knowledge). > > > Here is a zipped Android project of it. Please experiment with it and > > send results to here i.e. is it slow for you also after re-re-re-.. > > staring?www.kotiposti.net/lkelemen/android/testape2d.zip > > > thanks > > Lajos Kelemen > > > On Mar 31, 9:26 pm, shaun <shashepp...@gmail.com> wrote: > > > > I started going down the path of Object pooling. It seemed the only > > > solution when taking an existing engine and making work on a resource > > > constrained system like Android on a phone. Determining the strategy > > > for returning objects to the pool proved quite tough for me. I have > > > no doubt there are some experts on embedded systems programming with > > > tons of experience with object pooling. We just would be too lucky if > > > that person(s) was also experienced with Java, physics engines and had > > > a passion for open source and games! Is that too much to ask? LOL!! > > > > On Mar 31, 12:17 pm, mscwd01 <mscw...@gmail.com> wrote: > > > > > Thanks for your feedback Shaun, I too unfortunately think a bespoke > > > > engine will need to be written for Android, which is a real pity as > > > > the iPhone has several physics engines which can easily handle > > > > hundreds of objects. > > > > > Having said that Anton (2nd reply) has said he has an engine running, > > > > it would be nice to see a demo of this if that'd be possible? > > > > > Clark, i'd definately host any .apk's on my own site, I wouldn't put > > > > it on the marketplace if it wasn't a "finished" app - do people > > > > actually do that?! > > > > > I think i'll stay away from developing games with physics for the time > > > > being and concentrate on something else, I cant see it being feasible > > > > to include it any time soon which is a real pity. > > > > > On Mar 31, 3:28 pm, shaun <shashepp...@gmail.com> wrote: > > > > > > I am the author ofsimpull. > > > > > > Sorry guys for the demo being out of whack forSimpullto the Core. > > > > > The version of PulpCore that I integratedsimpullwith did not support > > > > > Chrome, but you should be able to see it in IE, FF Safari. It is nice > > > > > to take a look at that demo to get a feel for what the engine is > > > > > capable of, but the performance does not translate over to the fixed > > > > > point branch/version ofsimpullwhen running on Android. > > > > > > I ran tests on both the emulator and the actual device and there was a > > > > > significant increase in performance because of the fixed point > > > > > implementation, but I got very frustrated that it still did not > > > > > support the amount of objects in a scene that I considered good for a > > > > > physics-based game. It seemed to handle ~10 objects moving and > > > > > colliding OK. It has been a while since I was playing with it, so I > > > > > do not really remember the exact number of objects or the frame rate. > > > > > I mostly remember being upset with it. > > > > > > I am leaving the physics ideas for games out of the picture when > > > > > thinking Android for now. Someone would have to write a ground up > > > > > engine with all the performance and memory concerns of Android in > > > > > mind, which was not the case withSimpull.....I created it for > > > > > applets, then thought to port over to fixed-point for Android. It > > > > > works well with small scenes, but certainly not the staple engine to > > > > > use in my opinion. > > > > > > Also, Phys2D will not run worth a damn on Android. I tried it and I > > > > > even went through some heavy performance tuning. Garbage collection > > > > > is the major issue even after all I did. I seriously doubt JBox2D > > > > > will run well either. I'll stick to what I said earlier, a ground-up > > > > > solution by someone smarter than me is probably required. > > > > > > On Mar 31, 9:49 am, "admin.androidsl...@googlemail.com" > > > > > > <admin.androidsl...@googlemail.com> wrote: > > > > > > Not tried but if you can provide us with some example source code or > > > > > > put something on the market, I'm sure we could take a look. > > > > > > > G1 performance is significantly faster than emulator, but there are > > > > > > limitations. > > > > > > > Particularly with garbage collection and memory allocation on code > > > > > > that gets run continuously in loops, so I don't know how optimised > > > > > > these physics engines are for this purpose. > > > > > > > Would be interesting to find out though. > > > > > > > On Mar 31, 12:52 pm, mscwd01 <mscw...@gmail.com> wrote: > > > > > > > > Oh I forgot to re-ask... > > > > > > > > "Has anyone tested Phys2D or JBox2D on an actual device to see if > > > > > > > they > > > > > > > run better than on the emulator? > > > > > > > > I have a feeling the performance will better on a G1 than the > > > > > > > emulator > > > > > > > for some reason! > > > > > > > > On Mar 31, 12:51 pm, mscwd01 <mscw...@gmail.com> wrote: > > > > > > > > > I did take a look atSimpull, however the demo application > > > > > > > > failed to > > > > > > > > run as it relied on some library which wasn't supplied or > > > > > > > > referenced > > > > > > > > to - I just got annoyed after spending two days failing to get > > > > > > > > Phys2D > > > > > > > > and JBox2D to work in Android and didn't bother trying to work > > > > > > > > out the > > > > > > > > problems! > > > > > > > > > I might give it another look though... > > > > > > > > > On Mar 30, 10:41 pm, Streets Of Boston <flyingdutc...@gmail.com> > > > > > > > > wrote: > > > > > > > > > > I wonder how well this one works on Android: > > > > > > > > > > http://code.google.com/p/simpull/ > > > > > > > > > > -- Anton Spaans > > > > > > > > > > On Mar 30, 4:58 pm, Anton <socialhac...@gmail.com> wrote: > > > > > > > > > > > I have a simple 2D physics engine written and running. > > > > > > > > > > It uses > > > > > > > > > > the now famous Jacobson physics tricks (Verlet integration > > > > > > > > > > and hard > > > > > > > > > > constraints). I can manage 40 balls on the screen, with > > > > > > > > > > fill n^2 > > > > > > > > > > interaction between balls. I am working on spatial data > > > > > > > > > > structure > > > > > > > > > > optimizations now to improve the computational complexity > > > > > > > > > > of the > > > > > > > > > > collision detection code. I run the constraint update loop > > > > > > > > > > five times > > > > > > > > > > per frame and get 30 frames per second. Once the engine is > > > > > > > > > > up and > > > > > > > > > > running there are no memory allocations done in my program. > > > > > > > > > > And once > > > > > > > > > > the system settles down from the app launch there are very > > > > > > > > > > few GC > > > > > > > > > > events from other programs. Though they do still happen. > > > > > > > > > > Viewing > > > > > > > > > > LogCat I see a GC every 10 or 20 seconds because of some > > > > > > > > > > background > > > > > > > > > > application. But between those events I get a consistent > > > > > > > > > > frame rate. > > > > > > > > > > I am using OpenGL for my rendering. > > > > > > > > > > > -Anton > > > > > > > > > > > On Mar 30, 1:14 pm, mscwd01 <mscw...@gmail.com> wrote: > > > > > > > > > > > > Does anyone know of, or have implemented, a physics > > > > > > > > > > > engine which runs > > > > > > > > > > > smoothly in Android? > > > > > > > > > > > > I have spent the last couple of days trying Phys2D and > > > > > > > > > > > JBox2D, however > > > > > > > > > > > both perform very poorly - I am struggling to get even a > > > > > > > > > > > few objects > > > > > > > > > > > to simulate smoothly as frequent garbage collection > > > > > > > > > > > spoils it. > > > > > > > > > > > > One question I do have is will these run smoother on an > > > > > > > > > > > actual G1 > > > > > > > > > > > device or is the performance of the emulator accurate? > > > > > > > > > > > > Thanks- Hide quoted text - > > > > > > > > > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Android Developers" group. 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