On 7/30/2015 7:07 PM, Bald Eagle wrote:
> OK, so the problem and its solution is clearer in my heat-addled brain.
>

Lucky you :)
Mine is addled by medications :(

> I figured at some point I had to take into account the movement of an element
> (spoke or tooth) by a multiple of the distance between adjacent elements.

Distance not angle, or is that a figure of speech?
Oh national bird of America. ;)
Do you realise that this is taking me back 50 years to high school?

> So I used mod() to give me the remainder, and compared this number of degrees to
> half the distance between adjacent elements.
>

Are you trying to eliminate the effect or show it?

Also what frame rate are you encoding the animation? I think you have to 
take that into account too (also).

Have you tried a test with a single wheel?


> I send that all out to a debug stream and get the data below - but it's wrong.
> I get the Western Wheel effect with the gear teeth even though my calcs and the
> "1/2 distance" theory agree.
>
> Also, is "clock_delta" busticated in 3.7?  It never registers any value other
> than zero over all 37 frames.
>

I've never had the need to use clock_delta so I can't help there.

> :(
>
> I use:
> #declare Degrees = clock * 360;

Hmm! I use frame_number and keep the clock range between 0 & 1. I find 
that it is easier to modify things that way. When I want something to 
happen at a particular time. Although it probably doesn't mater here.

> and
> // ROTATION FOR ANIMATION
> // Clockwise = Negative

Widdershins! Dangerous!  ;)

I had a quick look at Friedrich's site (not the code) and I think that 
you might be trying to correct two illusions at the same time. I would 
either just concentrate on the spokes and let the gears look after 
themselves or greatly increase your frame rate. So that both the gear 
teeth and spokes only incrementally move between frames. Not more than a 
sixth of a revolution as the spokes do.
Notice Friedrich used a solid gear so did not have your problem. Also 
Friedrich did not use a cotter pin, or similar on the axle. That way he 
did not have to run the animation for a full revolution of the large gear.

>   rotate <0, 0, -(Degrees*7)>
>
> ==============================================
> Animation Information:
> Number of frames: 37.0
> Clock  Delta: 0.0
>
> Wheel2652: 55.0
> Degrees between teeth: 6.55
> Gear tooth movement between frames: 68.1 degrees
> Multiple: 10.405
> Western Wheel limit between frames: 3.27 degrees
> 0.405 x 6.55 = 2.65
>   10 x 6.545 = 65.455 + Remainder: (2.65) = 68.1 degrees
> 2.65 is less than 3.27
> OK - Normal Movement
>
> Wheel2652A: 5.0 (spokes)
> Degrees between teeth: 72.00
> Gear tooth movement between frames: 68.1 degrees
> Multiple: 0.946
> Western Wheel limit between frames: 36.00 degrees
> 0.946 x 72.00 = 68.11
>    0 x 72.000 = 0.000 + Remainder: (68.11) = 68.1 degrees
> greater than 36.00
> *** Western Wheel problem ***
>
>


-- 

Regards
     Stephen

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