This note outlines how the coupling between the motion of rigid bodies immersed in a fluid and the motion of this fluid is handled in XNS. For a rigid body one has a group of nodes which define the surface of the rigid body called “reference node group” (RNG). For each RNG we save the properties of motion in arrays which in the following we will call “RNG arrays”. They contain the bottom and to...

Rigid Body Simulation deals with trying to model real world physical situations computationally by applying Newton’s laws of motion to perfectly rigid bodies. Work done in this area is used in the animation industry, haptic displays in robotics, and 3D games, so there is a real need for algorithms that work in realtime. The two main areas of research in rigid body simulation are collision detec...

a 25 year-old construction worker underwent neck laceration following penetrating neck trauma in a falling incident. the 3rd tracheal ring was injured which was initially repaired and the patient was discharged in good general condition. (figure 1 shows the patient’s neck view after discharge from hospital).two months later the patient was again admitted due to provocative coughing and a metal ...

The difficulty of describing the positions of the body-fixed axis of a rotating body is approached through the use of Euler angles: spin ψ̇, nutation θ and precession φ shown below in Figure 1. In this case we surmount the difficulty of keeping track of the principal axes fixed to the body by making their orientation the unknowns in our equations of motion; then the angular velocities and angula...

Rigid body registration is one of the simplest forms of image registration, so this chapter provides an ideal framework for introducing some of the concepts that will be used by the more complex registration methods described later. The shape of a human brain changes very little with head movement, so rigid body transformations can be used to model different head positions of the same subject. ...

A 25 year-old Construction worker underwent neck laceration following penetrating neck trauma in a falling incident. The 3rd tracheal ring was injured which was initially repaired and the patient was discharged in good general condition. (Figure 1 shows the patient’s neck view after discharge from hospital).Two months later the patient was again admitted due to provocative coughing and a metal ...

In many virtual reality applications it is necessary to simulate the interaction among solid objects. One of the basic requirements is to ensure a non-penetration of rigid bodies. We show algorithms for detecting a collision of moving bodies along with the exact time of collision determination. Next we present a method for computation the postcollision velocities and positions of colliding obje...

During the last few years motion analysis has developed into a major field of interest in image analysis and understanding . Considerable progress has been made as evidenced by the number of publications . However , most of these have been confined to the study of rigid body mot ion . Very few have addressed the issue of non-rigid body motion which poses many interesting and difficult problems ...

These course notes will explain in details the physics behind rigid-body motion. Previously, we treated bodies as dimensionless “particles”. At time t, they existed in pointwise position x(t) with velocity v(t). Net force F(t) induced acceleration a(t), where F(t) = ma(t), with m as the mass of the particle. For readability, note that we mark vector quantities with bold notation: v ∈ R3 = (v1, ...