The action of grasping an object is very important for a humanoid agent with hand, evolving autonomously in a virtual world. If an agent is given the order "Grasp the object", he has to determine the portion of the object to grasp. In order to determine a grasping position, it is necessary to recognize the form of the 3-dimensional geometry, and detect portions which are suitable for grasp. Assuming that the object is grasped by one hand, we propose two techniques for detecting appropriate portions to be grasped on the surface of an object and for generating the grasping postures.

In this paper, our main contributions are as follows: The first is the detection of appropriate portions to be grasped on the surface of an object; The second is the formation of the hand shape to grasp various shaped objects. Using the two proposing methods, grasped positions and the hand shapes for each of them are computed. Moreover, these positions are evaluated by their stabilities using the robotics technique.