I Bilateral and unilateral constraints

  • I
  • Thread starter Thread starter hmparticle9
  • Start date Start date
  • Tags Tags
    Mechanics
hmparticle9
Messages
152
Reaction score
26
I am going through this course on collision detection: https://siggraphcontact.github.io/

In this link is a PDF called course notes. Scrolling down to section 1.3, called constraints.

In this section it is said that we can write bilateral constraints as ##\phi(\mathbf{x}) = 0## and unilateral constraints as ##\phi(\mathbf{x}) \ge 0##.

I understand that, but then it says that these constraints call also be written as:
$$\mathbf{J} \mathbf{u} = 0, \mathbf{J} \mathbf{u} \ge 0,$$
where
$$\mathbf{J} = \frac{\partial \phi}{\partial \mathbf{q}} \in \mathbb{R}^{m \times n},$$
and ##\mathbf{u}## is the velocity vector.

I am struggling with most of section 1.3, I will add bits as we progress.
 
Assume that this is a case where by sheer coincidence, two sources of coherent single-frequency EM wave pulses with equal duration are both fired in opposing directions, with both carrying the same frequency and amplitude and orientation. These two waves meet head-on while moving in opposing directions, and their phases are precisely offset by 180 degrees so that each trough of one wave meets with the crest of the other. This should be true for both the electric and magnetic components of...
Back
Top