Schlagwort-Archiv: OpenGL


Just found yet another AR library for Android called ARmsk. The description sounds promising. But the demo video is kind of shocking. They have like half a frame per second. The code looks like they used a lot of examples, like the OpenGL Cube renderer from the Android API demos and some stuff from the OpenCV-Android examples.

Last updates were in January this year, so quite up-to-date actually.

Oh, btw, guys why can't I find you when I search for "AR Android". I mean seriously, take care of your website keywords ;-)


AndEngine is a 2D OpenGL Engine. Actually a game engine. But it has also some small AR extension. I've stumbled upon this project a little while ago but then somehow forgot about it and now rediscovered it. So far it looks promising (even though I already found some kind of "lazy bug" which prevents the AR example to run :? ). Especially the the animation stuff and sensor helpers look great.

Hopefully this can boost my project a little.Will see.

[Note] floating-point/fixed-point operations versus OpenGL

From the Android NDK example "bitmap-plasma":

We're going to perform computations for every pixel of the target bitmap. floating-point operations are very slow on ARMv5, and not too bad on ARMv7 with the exception of trigonometric functions. For better performance on all platforms, we're going to use fixed-point arithmetic and all kinds of tricks

I stumbled upon this one or two times before. So it really seems like this is an issue needed to be addressed, since I want to do lots of heavy pixel-by-pixel computation stuff (a.k.a. image processing). Maybe there is a better way to do this: instead of translating everything from floating-point to fixed-point operations or even finding and implementing "all kind of tricks", I could do everything with OpenGL. Android 1.6 supports OpenGL ES 1.1 and from Android 2.0 and up OpenGL ES 2.0 is supported. Such OpenGL-operation are probably performed on the same CPU, but I assume if OpenGL is doing some floating-to-fixed-point translation this is more effective than I could do.