On 7/30/2015 2:39 AM, Bald Eagle wrote:
>
> So, I would normally just puzzle this out myself, but it's 98 degrees here
> (Fahrenheit, not rotationally  ;)  ) and my gray matter is cooked.
>
> Anyway, concerning the "Western Wheel" problem:
> http://www.f-lohmueller.de/pov_tut/animate/anim13e.htm
>
> I have a gear that turns 7 times in 37 frames.
> (it drives a gear that turns once per 7 revolutions, I'm doing a quick "36"
> frames, and cyclic animation is on - so it's 37)
> It has 5 spokes, and 55 gear teeth.
>
> I'm assuming I take 360 degrees, then divide by 55 teeth, and multiply by 7
> revolutions to get the total apparent movement of a tooth.  Then divide by 37
> frames to find the "apparent movement" of a tooth between frames in degrees.
>
> The "Western Wheel limit" is half of the span between teeth per frame, so that
> would be (360/55)/2.
>
> If the first calculation is correct, then if it's less than the limit, I
> shouldn't get the undesired visual effect.  Correct?
>
> Could someone check my logic / math?
>
> Thanks  :)
>
>
>
>
Your grey matter is cooked? So is mine and it is cool here.
I will have a look at your calculations a bit later.
I did something similar a few years ago and uploaded it to youtube a 
couple of years ago.
https://www.youtube.com/watch?v=BOjKESXP814
and
https://www.youtube.com/watch?v=XTBurdd1Ad4


I think that I did not want to see the gears going backward so I did not 
do your type of calculations.
What I did do was to split the animation into cyclic parts.
For instance if in your animation the gear turns 5 times in the time 
frame. Then you only need to code a fifth of the revolutions and repeat 
that continuously. That way you can have a faster frame rate. This will 
mean that the angle moved each frame is smaller.
With your figures each frame will rotate the gear 68.108 degrees. I see 
a problem with that. Of course this technique relies on the symmetry of 
the object.

The other thing is, using Pov's cyclic animation. You don't render one 
frame less as PovRay does the donkey work in calculating the clock 
delta. I think that is how it works but it is a long time since I have 
used it.






-- 

Regards
     Stephen

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