Program, information storage medium, information processing system, and information processing method for controlling a movement of an object placed in a virtual space

1. A program stored in a non-transitory computer readable information storage medium, for causing a computer to function as an information processing system for controlling a movement of an object placed in a virtual space, the program including:

object changing instructions to change at least one of a position and a direction of an object to be moved placed in the virtual space based on a value of a parameter associated with a physical quantity that is an attribute of the object to be moved;

first change determination instructions to determine a first change in the physical quantity of the object to be moved, the first change corresponding to a user's operation;

second change determination instructions to determine a second change in the physical quantity of the object to be moved, the second change corresponding to and different from the determined first change; and

value changing instructions to change a value of the parameter based on the first change and the second change,

wherein the object changing instructions include instructions to change, after the value of the parameter is changed, at least one of the position and the direction of the object to be moved based on the changed value of the parameter,

wherein the first change determination instructions include instructions to determine changing a force applied to at least one of a plurality of elements included in the object to be moved, and

wherein the second change determination instructions include instructions to determine changing a mass or a moment of inertia of at least one of the elements.

2. The program according to claim 1 ,

wherein the first change determination instructions include instructions to determine a change in at least one of a velocity and an angular velocity of the object to be moved with respect to a specific direction,

wherein the second change determination instructions include instructions to determine a change in at least one of a velocity and an angular velocity of the object to be moved with respect to a direction different from the specific direction.

3. The program according to claim 2 , wherein

under a condition that the first change determination instructions include instructions to determine increasing at least one of the velocity and the angular velocity of the object to be moved with respect to the specific direction, the second change determination instructions include instructions to determine decreasing at least one of the velocity and the angular velocity of the object to be moved with respect to the direction different from the specific direction.

4. The program according to claim 1 , wherein

the second change determination instructions include instructions to determine increasing at least one of the mass and the moment of inertia of at least one of the elements in which the change in the force is determined, and decreasing at least one of the mass and the moment of inertia of at least one of the rest of the elements.

5. The program according to claim 4 , wherein

the second change determination instructions include instructions to determine increasing at least one of the mass and the moment of inertia of at least one of the elements in which the change in the force is determined, and decrease at least one of the mass and the moment of inertia of all of the rest of the elements.

6. The program according to claim 4 ,

wherein the object changing instructions include instructions to change at least one of the position and the direction of the object to be moved based on values of a plurality of parameters, each of the parameters being associated with at least one of a mass and a moment of inertia of each element, and

wherein the value changing instructions include instructions to change a value of a parameter associated with at least one of a mass and a moment of inertia of an element in which an increase or a decrease in at least one of the mass and the moment of inertia is determined.

7. The program according to claim 1 , wherein

the program further includes instructions to generate an image representing the virtual space, in which the object is placed, viewed from a viewpoint defined in the virtual space.

8. A non-transitory computer readable information storage medium storing a program for causing a computer to function as an information processing system for controlling a movement of an object placed in a virtual space, the program including:

object changing instructions to change at least one of a position and a direction of an object to be moved placed in the virtual space based on a value of a parameter associated with a physical quantity that is an attribute of the object to be moved;

first change determination instructions to determine a first change in the physical quantity of the object to be moved, the first change corresponding to a user's operation;

second change determination instructions to determine a second change in the physical quantity of the object to be moved, the second change corresponding to and different from the determined first change; and

value changing instructions to change a value of the parameter based on the first change and the second change,

wherein the object changing instructions include instructions to change, after the value of the parameter is changed, at least one of the position and the direction of the object to be moved based on the changed value of the parameter,

wherein the first change determination instructions include instructions to determine changing a force applied to at least one of a plurality of elements included in the object to be moved, and

wherein the second change determination instructions include instructions to determine changing a mass or a moment of inertia of at least one of the elements.

9. An information processing system for controlling a movement of an object placed in a virtual space, comprising:

an object changing unit for changing at least one of a position and a direction of an object to be moved placed in the virtual space based on a value of a parameter associated with a physical quantity that is an attribute of the object to be moved;

a first change determination unit for determining a first change in the physical quantity of the object to be moved, the first change corresponding to a user's operation;

a second change determination unit for determining a second change in the physical quantity of the object to be moved, the second change corresponding to and different from the determined first change; and

a value changing unit for changing a value of the parameter based on the first change and the second change,

wherein the object changing unit changes, after the value of the parameter is changed, at least one of the position and the direction of the object to be moved based on the changed value of the parameter,

wherein the first change determination unit determines changing a force applied to at least one of a plurality of elements included in the object to be moved, and

wherein the second change determination unit determines changing a mass or a moment of inertia of at least one of the elements.

10. An information processing method for controlling a movement of an object placed in a virtual space, the method comprising:

changing at least one of a position and a direction of an object to be moved placed in the virtual space based on a value of a parameter associated with a physical quantity that is an attribute of the object to be moved;

determining a first change in the physical quantity of the object to be moved, the first change corresponding to a user's operation;

determining a second change in the physical quantity of the object to be moved, the second change corresponding to and different from the determined first change;

changing a value of the parameter based on the first change and the second change; and

changing, after the value of the parameter is changed, at least one of the position and the direction of the object to be moved based on the changed value of the parameter,

wherein the first change changes a force applied to at least one of a plurality of elements included in the object to be moved, and

wherein the second change changes a mass or a moment of inertia of at least one of the elements.