i’m beginner .please ,how can i start to design 3D interface. which language is more flexible java 3D or c++.
What do you mean by “3D interface” ?
Java 3D is an API not a language, Java is a language, java3D is a high level 3D api for Java, it has nothing to do with OpenGL and works at a much higher level with a scene graph.
Java3D is “dead”, as it look’s now it will not eveolve, SUN will fix bugs but that’s about it.
What language to use is a question of taste, I prefer C/C++, Java is another choice, there are a few nice OpenGL implementations for Java (JNI interface that call the opengl API), JOGL, gl4Java and so on (can be tricky to use togheter with swing because the OpenGL window must be a native window, this can cause overlapping problems with other swing widgets).
If you already now a language then I suggest you stick to it, then you just have to learn the OpenGL api, and not a new language at the same time.
There are also a number of high level C/C++ api’s available with scene graph support and so on, if you are into games then Crystal Space might be interesting (there are other 3D engines out there to).