On 9/6/2012 3:10 AM, scott wrote:
>>> In that case why not just model it as a point mass at B connected by a
>>> suitably stiff spring to point A? Keep track of the position and
>>> velocity of B and you can use normal numerical integration to update B
>>> (there will be a gravity force and a spring force towards A). In your
>>> graphics you can use the angle between the vertical and the line A-->B
>>> to draw your train.
>>>
>>> It may not be 100% physically accurate but much simpler than trying to
>>> work through all the maths related to dynamics in a rotating reference
>>> frame...
>> Uh, yeah, so how do you do that? lol Seriously, the closest I have come
>> to differentials is a book promising to take you from basic math up to
>> basic calculus, and I got lost like 3/4 of the way through it. :p But,
>> yeah, it sounds good...
>
> This is a good guide, there's some other good articles on his site too.
>
> http://gafferongames.com/game-physics/integration-basics/
>
> I don't know how much you've done already on this kind of stuff, but
> even after 4-5 years of learning calculus the rotating reference stuff
> was scary hard. From what I remember, mainly because your unit vectors
> are no longer constant, so no longer disappear when you differentiate
> them...
>
I have done.. almost nothing. Like I said, never took calculus at all, 
and the book I read through derailed about where the equations got into 
integration and differentials. I did pick up a few interesting trick 
about raising to powers and negative powers that I had no idea was 
possible, but otherwise.. confusing as hell. I need to sit down one of 
these days and actually try to work out what they are doing.

> This is the demo we had in one of our lectures:
>
> http://www.youtube.com/watch?v=kc88SrMG5fA
>
> Fun to watch, but try to prove the physics :-)

O.o

Ok, yeah, that is.. not something I would have predicted. lol

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