M3G how to create collisions?

[Maxtremus]

I created my .m3g file, set a camera (I use as a character, like a FPS game), the World object and everything else to make the application appear, but I have the following problem, I don'tknow how to implement collisions, I'd like to make my camera collide with the scenary? I heard it has something to do with RayIntersection class and pick() method, I just want to check if the entity is collided, the collision response I can implement by myself, how do I make it?

[Maxtremus]

I did this

Class extends GameCanvas {
   Object3D[] o3d;
   Camera cam;
   World w;
   
   public Class(){
       //load object 3D .m3g
       //create camera
       //put the object 3D and the camera in the same world
   }
   
   run(){
      while(){
          g3d.bindTarget(g);
            cam.translate(0.0f, 0.0f, 1.0f);
            g3d.render(w);
          g3d.releaseTarget();
          
          flushGraphics();
      }
   }
}

Does anybody know how to "check" the collision from the camera to the meshes in .m3g file?