Snecma

Snecma Moteurs

Edouard Ramstein

Bruno Maille

Patrick Chedmail

Yann Lebret

A method of moving a virtual articulated object in a succession of individual movements in a virtual environment, the articulated object being specified in the environment by a global position, a global orientation, and a plurality of joint angles defining the positions of a set of articulated elements making up the articulated object with a plurality of degrees of freedom. The method includes the steps of calculating an interaction distance between the articulated object and its environment; extracting from the interaction distance a first point belonging to one of the elements of the articulated object, and a second point belonging to the environment; and defining a single extraction vector from the first and second points. The method further includes the step of moving the articulated object away from its environment by a movement defined as a function of the single extraction vector and acting on the global position, and/or the global orientation, and/or the degrees of freedom of the articulated object so as to avoid a collision between the articulated object and the environment.

Moving a virtual articulated object in a virtual environment while avoiding collisions between the articulated object and the environment

To make it easier to manipulate in direct action and to manage the degrees of freedom of a virtual dummy, the invention provides a graphical interface system enabling two windows to be displayed on a screen. The first window contains an overall representation of the dummy making it possible, using pointer means such as a mouse, for example, to select a member of the dummy directly on the screen. In response to such selection, the selected member appears in the second window on a larger scale together with symbols indicating all of the degrees of freedom available on the member in question. The operator can then act directly on the symbols of the degrees of freedom to block or unblock them or indeed to manipulate the dummy in direct action.

Graphical interface system for manipulating a virtual dummy

A method of moving a virtual articulated object in a virtual environment in a succession of unit movements, the articulated object including a set of articulated elements connected together by a set of joints, the relative positions of the articulated elements being defined by a plurality of joint angles about a plurality of degrees of freedom. The method includes the steps of calculating an interaction distance between a given articulated element and the other articulated elements of the articulated object; extracting from the interaction distance, a first point belonging to the given articulated element, and a second point belonging to one of the other articulated elements of the articulated object; and defining a single extraction vector from the first and second points. The method further includes a step of moving the given articulated element away from the other articulated elements of the articulated object in a movement defined as a function of the single extraction vector by acting on the degrees of freedom of the articulated object in order to avoid a collision between the given articulated element and the other elements of the articulated object.

Moving a virtual articulated object in a virtual environment while avoiding internal collisions between the articulated elements of the articulated object

A multi-agent method and system for moving a virtual dummy in a virtual environment, the dummy being defined by an overall position and by a plurality of degrees of freedom for joints. The method includes a contribution from an attraction agent acting on the plurality of degrees of freedom of the joints of the dummy to move the dummy towards the target; and a contribution from an avoider agent acting on the overall position of the dummy as a function of parameters defining the environment in order to avoid collisions between the dummy and said environment. The method further includes a contribution from an ergonomy agent acting on the plurality of degrees of freedom of the joints of the dummy in order to correct the posture of the dummy automatically while it is moving towards the target.

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Melun, France

Edouard Ramstein