hey everyone.. i have project to do virtual reality game by using Maya. i want t ask how i can connect head mounted display (HMD) to Maya. is it possible to make user can smell the environment in the game, what is the device which may use to do that and is that work with Maya ? I hope u to help me and explain that to me in details Thank u so much

Maya is not a runtime tool; it is a tool where you can create art that you can then use in a runtime. Runtimes used for virtual reality, games, and virtual worlds range from simple open source solutions (Irrlicht, Nebula, Quake 3, etc) through commercial game engines of various quality (Torque, Id, Source, etc) through online persistent world solutions (Second Life, OLIVE, etc).

You would want to connect the HMD to the runtime, not to Maya itself. If you just want a single-player experience, I'd use one of the simpler game engines. Many HMDs can be read as a multi-function joystick using DirectInput on Windows (the solution is different on other OS-es).

For scents, there used to be an "iSmell" device a few years ago which could do scents in games, but that failed in the market and you can't get it anymore. I suggest doing some googling on terms such as "digital scent".