问题
Assume I have 3 cubes in random location/rotation that are visible in the viewport. I want to be able to detect if which of the cube has been touched if I touch ( or click on emulator) a specific cube. If I just touch empty space instead of a cube, this should also be properly detected. I know there is onTouchEvent callback that you over-ride on a View but this only gives me x,y coordinate of where the touch occurred. I am looking for OpenGL-ES based solution and more specifically for Java based Android application.
回答1:
THere could be several objects (or none) that are on that x / y coordinate. You should find them all, and then if there are any, check the z-coordinate to see which one is the closest to the viewport (and so the one that was touched).
回答2:
Often wondered about best way to do this without glSelect()... this answer looks good: iPhone OpenGL ES - How to Pick
(You can ignore the fact it's an iOS question... the OpenGL ES API is the same on both platforms AFAIK).
来源：https://stackoverflow.com/questions/5040349/how-to-detect-which-3d-object-has-been-touched