I'd like to know the process of a video game. I asked a few professionals but they said it would come natural.

Like after the GDD is completely done.

whats the order of each persons role?

Artist, 3D modeler, Level Designer and programmer.

Hope this makes sense!

It really depends on your document. Once you have finished the GDD, then, depending on your game, you decide what to do first. For example, if you are making a First Person Shooter, you may go for models first, so then the artist has something to do. One thing's for certain, 3D modeler's pretty much always have to work before artists, but not necessarily, and same for programmer's, they will almost always end up in front of a Level Designer, because otherwise, the designer's may not have much to do.

I would want the enviroments done first. Characters, props etc. and everything in full 3D. then then the programmers.

when should the sound design come into play?

These things are often done by different teams who can work concurrently and communicate with one another about challenges, needs, etc. If you are working solo, then it depends on what angle you're coming at this from.

If you're a programmer, you want to leave art and sound assets until much later in development. Put together some placeholder art and get a prototype up and running; honestly I think sound will come last (or when you get around to getting some real art assets into place).

If you're an artist, dig in and draw up your awesome characters and scenes; concept art first, then models/sprites whatever you're going to do.

I would want the enviroments done first. Characters, props etc. and everything in full 3D. then then the programmers.

when should the sound design come into play?

Having the environments and everything modeled in full 3D before you get the programmers in is usually - again, depending on the game - going to be a problem. There's not usually much point in modelling everything if you don't have a basis for the physics, the engine, collision detection, etc. If you're using, for example, the Unreal 3 engine then perhaps you could start doing modelling before you get other programmers in, but that's because a large chunk of the programming has already been done beforehand.

I would want the enviroments done first. Characters, props etc. and everything in full 3D. then then the programmers.

when should the sound design come into play?

Having the environments and everything modeled in full 3D before you get the programmers in is usually - again, depending on the game - going to be a problem. There's not usually much point in modelling everything if you don't have a basis for the physics, the engine, collision detection, etc. If you're using, for example, the Unreal 3 engine then perhaps you could start doing modelling before you get other programmers in, but that's because a large chunk of the programming has already been done beforehand.

thank you!