Recent content by Kludgy

  1. K

    Numeric precision with iterative matrix rotations

    Velocity verlet does look interesting! Looking at that now..
  2. K

    Numeric precision with iterative matrix rotations

    Yeah I read that paper on particle based simulation. I do like the advantage of the particle part of that, not having any explicit angular state at all. I wonder how it would behave with my angular control laws? Verlet integration in general would let me drop the first order state...
  3. K

    Numeric precision with iterative matrix rotations

    Well I am using a quaternion to describe the orientation. Quaternions or not, I get the same drift problem. Now that you mention that I think I'm wrong and it's not matrix conditioning but just the poor naive integration involved. I noticed yesterday that using smaller simulation steps...
  4. K

    Numeric precision with iterative matrix rotations

    I couldn't find a forum section on numerical analysis, so I'm writing this here. I'm on the lookout for simple matrix rotation/multiplication methods that can overcome the precision problems associated with poorly conditioned matrices. In my case I'm trying to simulate the rotational...
  5. K

    Small numbercial analysis question

    Wow, well in the case of integers it is a simpler problem. Extending floating point datatypes is more complicated. It is not so hard to create a larger integer class as long as you follow the same bitwise rules than intrinsic integer types follow. And the basic arithmetic operators can be...
  6. K

    Cartwheeling/spinning rod problem

    Ok correction again I'm wrapping this up. :) It's not the orthonormalize, but if I subdivide the simulation step 500 times everything is much more stable. Thanks for the help! I'm off to look for better integration approaches...
  7. K

    Cartwheeling/spinning rod problem

    Yea it's a numerical bug coming from orthonormalize since the spin always converges on the same world space axis.
  8. K

    Cartwheeling/spinning rod problem

    Ok I think I got it, using an instantaneous world space inertia tensor to calculate the angular velocity at the beginning of each step. Now I can get a spin and tumble. My new problem is that there is a strange energy transfer in the simulation. Maybe it's normal, but physics is not my...
  9. K

    Cartwheeling/spinning rod problem

    Do you mean like supplying a non-diagonal inertia tensor matrix to the calculation?
  10. K

    Cartwheeling/spinning rod problem

    Hi, I'm stuck with the simulation of something that is very intuitive in reality. It's easy to produce a combined cartwheeling and spinning motion with a screwdriver by flicking the wrist at the right time. But what combination of angular parameters describes the evolution of this...
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