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I have been reading about physics engines, I have a reasonably OK understanding force based models and 6 dof integration.

I'm still confused on how impulse based models work.

What define the equations of motion for impulse based engines? Ex, what is a time step in them?

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  • $\begingroup$ Obligatory link to the canonical SIGGRAPH paper about momentum-based physics modeling cs.cmu.edu/~baraff/sigcourse/notesd1.pdf and the for collisions cs.cmu.edu/~baraff/sigcourse/notesd2.pdf $\endgroup$
    – John Alexiou
    Commented Jun 9 at 18:09
  • $\begingroup$ Does this answer your question? Is this the correct way to integrate orientation given torque and inertia tensor? $\endgroup$
    – John Alexiou
    Commented Jun 9 at 18:11
  • $\begingroup$ I'm basically trying to understand the key differences between the two and the equivalent equations of each. $\endgroup$
    – FourierFlux
    Commented Jun 9 at 18:36
  • $\begingroup$ One integrates $$ \begin{pmatrix}\Delta\boldsymbol{v}\\ \Delta\boldsymbol{\omega} \end{pmatrix}=\int\begin{pmatrix}\boldsymbol{F}/m\\ {\rm I}^{-1}\left(\boldsymbol{\tau}-\boldsymbol{\omega}\times{\rm I}\boldsymbol{\omega}\right) \end{pmatrix}{\rm d}t$$ and the other $$\begin{pmatrix}\Delta\boldsymbol{p}\\ \Delta\boldsymbol{L} \end{pmatrix}=\int\begin{pmatrix}\boldsymbol{F}\\ \boldsymbol{\tau} \end{pmatrix}{\rm d}t$$ where $\begin{pmatrix}\boldsymbol{p}\\ \boldsymbol{L} \end{pmatrix}=\begin{pmatrix}m\boldsymbol{v}\\ {\rm I}\boldsymbol{\omega} \end{pmatrix}$ is the momentum vectors. $\endgroup$
    – John Alexiou
    Commented Jun 10 at 14:24
  • $\begingroup$ But how is this fundamentally different? I'm still not seeing it since it appears to basically be a rewriting of the above. I'm guessing it is only relevant to contact interactions? But then the same basic interactions still apply. $\endgroup$
    – FourierFlux
    Commented Jun 11 at 6:37

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