How to detect if part or all of object overlaps with another object in Android OpenGL-ES application?

Assume I have 3 cubes at random location/orientation and I want to detect if any of the cube is overlapping (or collidi开发者_运维知识库ng) with another cube. This overlap or collision could also happen as the cubes location/rotation are changed in each frame. Please note that I am looking for Android based and OpenGL ES (1.0 or 1.1) based solution for this.

This isn't really an OpenGL problem - it just does rendering. I don't know of any ready-made android libraries for 3D collision detection, so you might just have to do the maths yourself. Efficient collision detection is generally the art of using quick, cheap tests to avoid doing more expensive analysis. For your problem, a good approach to detecting if cube A intersects cube b would be to do a quick rejection test, either

1. Compute the bounding spheres for A and B - if the distance between the two sphere's centers is greater than the sum of radii, then A and B do not intersect
2. Compute the axis-aligned bounding boxes for A and B - if the bounds do not intersect (very easy to test), then neither do A and B

If the bounds test indicates possible collision it's time for some maths. There are two ways to go from here: testing for vertex inclusion and testing for edge/face intersection

Vertex inclusion is testing the vertices of A to see if they lie within B: either rotate the vertex into B's frame of reference to test for inclusion, or use the planes of B's faces directly in a frustum-culling style operation.

Edge/Face intersection is testing each of the edges of A for intersection with B's face triangles.

While the vertex inclusion test is a bit cheaper than Edge/Face testing, it's possible for cubes to intersect without encompassing each other's vertices, so a negative result does not mean no intersection. Similarly, it's possible for cubes to intersect without an intersection between an edge and a face (if one lies within the other). You'll have to do a little of both tests to catch every intersection. This can be avoided if you can make some assupmtions about how the cubes can move from frame to frame, i.e.: if the A and B were not touching last frame, it's unlikely that they are A is wholly within B now.