Method and apparatus for providing simulated physical interactions within computer generated environments

A computer system for simulating the spatial interaction of a displayed first simulated object with a displayed second simulated object in a computer-simulated spatial environment such that the user is provided with a force feedback that realistically represents said interaction, comprising:

• a processor for executing a simulation including a first simulated object, said simulation being configured to implement the motion of said first simulated object in response to motion of a physical object of an interface device controlled by a user, wherein said physical object has a physical position in a physical environment, and wherein a position control mapping between said simulated location of said first simulated object and said physical position of said physical object is created, said simulation being further configured to generate a second simulated object having boundaries such that said second simulated object impedes the simulated motion of said first simulated object when the trajectory of said first simulated object intersects said boundaries of said second simulated object;
• a display device for viewing the location and motion of said first simulated object and said second simulated object;
• and
• a force feedback mechanism configured to impart to a user of said computer system a physical sensation that corresponds to the simulated physical interaction of said first simulated object with said second simulated object when the trajectory of said first simulated object intersects the boundaries of said second simulated object, wherein said interaction is determined by examining a current location and a previous location of said first simulated object to determine said trajectory, and wherein said position control mapping between said physical object and said first simulated object is broken during said interaction when providing said physical sensation.

A method for providing force feedback for interacting simulated objects in a simulation implemented on a computer system, the method comprising:

• displaying a user-controlled first simulated object and a second simulated object on a display device of a computer system, said first simulated object moving on said display device during a simulation in response to manipulations of a physical object of an interface device by a user according to a position control paradigm, said interface device being coupled to said computer system;
• determining when said first simulated object engages said second simulated object within said simulation;
• displaying said determined engagement of said first simulated object with said second simulated object, wherein said first simulated object has a simulated compliance of a predetermined amount and said second object has a simulated mass of a predetermined amount wherein an elongation of said first graphical object is displayed in accordance with said predetermined simulated compliance and said predetermined simulated mass at a point of impact with said second simulated object;
• and
• outputting a force command to said interface device to apply a force to said physical object manipulated by said user in at least one degree of freedom provided by said interface device, said force being applied in the direction of said engagement of said second simulated object with said first simulated object and having a magnitude in accordance with said simulated mass of said second simulated object.

A method for providing an interaction between displayed objects in a graphical environment implemented by a host computer, wherein a user interfaces with said graphical environment using a force feedback device coupled to said host computer, the method comprising:

• moving a first graphical object in response to movement of a user manipulatable object of said force feedback device by said user, said movement of said first graphical object provided according to a position control mapping to said movement of said user manipulatable object;
• determining whether said first graphical object has engaged a second graphical object by examining a path of said first graphical object in said graphical environment, said path determined by examining a current location of said first graphical object and a previous location of said first graphical object;
• breaking said position control mapping and providing an illusion of rigidity of said second graphical object by displaying said first graphical object as remaining engaged with said second graphical object when said path of said first graphical object has been determined to move through said second graphical object if said position control mapping were maintained;
• outputting an opposing force on said user manipulatable object by at least one actuator in said force feedback device in a direction approximately opposite to said path of said first graphical object while said first graphical object is engaged with said second graphical object.

A method for providing an interaction between displayed objects in a graphical environment implemented by a host computer, wherein a user interfaces with said graphical environment by manipulating a force feedback device coupled to said host computer, the method comprising:

• moving a displayed first graphical object in response to movement of a first physical object of said force feedback device, said movement of said first graphical object provided according to a position control mapping to said movement of said first physical object;
• moving a displayed second graphical object in response to movement of a second physical object, said movement of said second graphical object provided according to a position control mapping to said movement of said second physical object;
• determining whether said first graphical object has engaged said second graphical object;
• breaking said position control mapping for said first physical object and providing an illusion of rigidity of said engagement by displaying said first graphical object as remaining engaged with said second graphical object when said first graphical object and second graphical objects have been determined to move through each other to continue their motion if said position control mapping with said physical objects were maintained;
• and
• outputting an opposing force on said first physical object by at least one actuator in said force feedback device in a direction opposite to a direction of said motion of said first graphical object while said first graphical object is engaged with said second graphical object.