Computer graphics processing and selective visual display system – Computer graphics processing – Animation
Reexamination Certificate
1996-12-04
2001-09-04
Vo, Cliff N. (Department: 2671)
Computer graphics processing and selective visual display system
Computer graphics processing
Animation
Reexamination Certificate
active
06285379
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for controlling the movement of a virtual body, where the virtual body is a computer-based model that represents the human, or other, form in a computer-generated virtual environment.
The form taken by the virtual environment will depend on the intended use of the system and may, for example, comprise the interior of a building for an architectural modelling application, or urban or surreal landscapes for games or other applications, around which environment the virtual body controlled by the user is moved. In the following, the term “virtual environment” will be used for such virtual landscapes or situations: the term “physical environment” will be used to denote the ‘real-world’ surroundings of the user, for example a room in which the user contacts the various hardware devices, such as a head-mounted display (HMD), which provide the interface to the virtual environment.
The terms “virtual body” and “physical body” should be construed accordingly.
2. Description of the Related Art
One example of a control device in the form of a haptic glove is described in International Patent Application WO92/18925 (W. Industries). Within the virtual environment (viewed for example via HMD) the users hand appears as a cursor which undergoes changes corresponding with movement and flexure of the users hand. Contact between the cursor and objects within the virtual environment is simulated by inflating cushion portions of the glove to give a sensation of touch. Whilst the haptic glove is useful for techniques such as hands-on molecular modelling, within a virtual world where the object is to provide a sense of visual realism for the user, the changeable cursor (and the lack of the rest of a body) can detract from the users feeling of immersion.
A far more complex system, for generating and processing synthetic real-time environments is described in International Patent Application WO95/11479 (Redmond Productions). In the system described, the user is placed in a closed physical environment within which all the interaction occurs. On first use, a detailed virtual body for the user is built up, the process making use of detailed position sensing means within the physical environment to form a ‘wire-frame’ model of the users body. Onto the wire frame, the virtual body is built up to a high density image with shading and hidden surface removal using a library of stored male and female body parts of all shapes and ages. In order to provide stimuli to the user (in addition to stereo imaging and audio through an HMD), the closed chamber includes a number of interaction apparatuses including a variable resistance treadmill, tactile output devices (pixel-addressed banks of rods which can be pushed out to form shapes or surface textures) and a “cybercycle” vehicle simulator.
While this latter system may provide the user with a high degree of immersive realism, the processing power required to generate and animate the virtual body in addition to generating the virtual environment is extremely high.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a system for modeling a virtual body within a virtual environment, and controlling the movements of the virtual body in response to user body movement, which system is relatively simple to implement while providing acceptable (or better) levels of realism.
It is a further object of the present invention to provide, in such a system, easily implementable mechanisms for supplying feedback from the virtual environment to a user.
In accordance with the present invention there is provided a virtual body modeling apparatus operable to generate and animate under user direction a representation of a body in a virtual environment. A first data store, holds data defining the virtual environment. A second data store, holds data related to features of the virtual body representation. A motion detector and a processor is arranged to generate a representation of the virtual environment based on data from the first data store, to generate the body representation within the virtual environment based on data from the second data store, and to periodically modify the generated body representation in response to signals received from the user motion detector. The second data store holds data defining at least one sequence of body motions, and the processor is arranged to call the sequence data and modify the generated body representation to follow the sequence of motions on detection of one or more predetermined signals from the user motion detector.
By the use of pre-stored sequences of body motions (for example a walking sequence for the legs or a waving sequence for an arm) the need to monitor user movements and update the generated image of the virtual body to exactly follow the users execution of these movements is greatly reduced. Different speed sequences may be provided for a given body motion, or means may be provided to control the speed at which a sequence is reproduced.
The apparatus may suitably include means operable to generate feedback to the user to enhance the realism, with the feedback being generated in relation to the following of the sequence of motions, and at one or more predetermined points in the sequence. Such feedback may take a number of forms, including force feedback where means may be arranged to provide controllably variable resistance to movement of the users physical body, such as to simulate difficult conditions in the virtual environment. Another possible form of feedback is audio feedback (for example the user hearing the sound of his/her footsteps in the virtual world) with the apparatus including audio signal generation means and the feedback comprising an audio sequence generated at a predetermined point or points during the sequence of motions. A still further form of feedback is visual feedback which may be provided where the user is presented with the image of the virtual environment from a first viewpoint, and the generated representation of the virtual environment is modified to change the viewpoint in synchronism with the following of the sequence of motions.
As will be described hereinafter in terms of an exemplary embodiment, the motion detector may comprise a restraint coupled to a rotatable shaft and attachable to a users limb, with movement of the restraint by the user producing rotation of the shaft and the user motion being derived from the angular deflection of the shaft. With such an arrangement, force feedback may be provided in the form of an electromagnetic coil or the like to generate a torque opposing rotation of the shaft.
Also in accordance with the present invention there is provided a method for user-directed animation of a computer-generated representation of a body in a virtual environment. An initial position for the virtual body is determined within the environment. An image of the virtual body within the environment and presenting it to a user. Movement of the user in a physical environment is monitored and translated into movement of the virtual body relative to the virtual environment. The rendered and presented image is periodically updated. At least one pre-stored sequence of body motions is provided, and the generated body representation is modified to follow the sequence of motions on detection of one or a predetermined sequence of physical motions by the user. The rate of modification of the generated body representation may suitably be determined by a filtered (for example time averaged) value for speed of user movement, to result in a smooth movement of the virtual body, unaffected by short hesitations or the like on the part of the user.
REFERENCES:
patent: 4937444 (1990-06-01), Zimmerman
patent: 4988981 (1991-01-01), Zimmerman et al.
patent: 5214758 (1993-05-01), Ohba et al.
patent: 5347306 (1994-09-01), Nitta
patent: 5436638 (1995-07-01), Bolas et al.
patent: 5459382 (1995-10-01), Jacobus et al.
patent: 5483630 (1996-01-01), Unuma et al.
patent: 5490
Thorne Gregory L.
U.S. Philips Corporation
Vo Cliff N.
LandOfFree
Virtual body control device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Virtual body control device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Virtual body control device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2519321