thank you very much for your detailed answer.
1. i want to check visibility of objects visible in the frustum. iam developing a 3d based 2d game.
when i fire a bullet i wanna detach it from world an recycle it in my pool as soon as it lefts the outer bounds of my scene.
right now i use max y and x values for this.
but because of the spheric view the x coords dont match the screen bounds on the max y coords. i hope you get what i mean..
the camera is not straight top down..
i possibly could use interact2d3d methods to get the world coords with 0/0 and viewport width/height to get the proper world coords to check against to determine if an object left the camera sight.. didnt tryed yet.

2. well that sounds good. sounds like its already what i wanted. that also means if i have build my game around an fixed x/y world point. this point will stay the same in any ratio?
for example if in my scene on my phone the max y value is 10 then it is on any other phone the same?

3. i think each min is not that bad.
is there no way to provide a pool or a parameter like gettranslation(simplevector) for the collisions?

i have about 50 primites moving as background objects.. maybe there is another way to simulate movement of a vehicle without creating primitives that move in a direction to simulate that..?
i will try the new released version.
i have android 4 on my phone so i dont think this is the issue.
and i only used normal for loops on android.
i thank you very much.
//edit:
another question which come to my mind is..
does world.getobjects() creates an new enumeration object each time called or is it cached somehow? than i do not need to use my own arraylist to cycle through all my objects. i could use that one.. but i didnt want to create new objects without need.