1. A method for moving an avatar in a virtual environment along an elevation based on a movement of a person in a motion capture volume along a substantially level ground surface, the method comprising: mapping the person from the motion capture volume to the virtual environment, wherein the person is represented by the avatar in the virtual environment; determining an offset in the elevation and an offset in an orientation of the avatar in the virtual environment with respect to a terrain of the virtual environment in correlation to an elevation and an orientation of the person in the motion capture volume, wherein determining the offset in the elevation and the offset in the orientation of the avatar in the virtual environment comprises: generating, by a computer, one or more rays in the virtual environment that originate at a predetermined height above one or more portions of the avatar's body in the virtual environment and are directed towards the terrain of the virtual environment, wherein the one or more portions of the avatar's body from which the one or more rays are generated are determined based on an action of the person in the motion capture volume; intersecting the one or more rays with a collision mesh that defines the terrain of the virtual environment; and computing a point of intersection of each of the one or more rays with the collision mesh; adjusting, by the computer, the elevation and the orientation of the avatar in the virtual environment to compensate for the offset in the elevation and the offset in the orientation of the avatar and to align the avatar with the terrain of the virtual environment; and displaying, to the person in the capture volume, a view of the virtual environment from the adjusted elevation and orientation of the avatar in the virtual environment.