Stephen <mca### [at] aolcom> wrote:

> Lucky you :)
> Mine is addled by medications :(

In some instances, you could be the luck one :D

> > 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?
I suppose it's a figure of speech or just lazy language - since arcs of the
circumference are subtended by angles.

> Oh national bird of America. ;)
It's a sort of many-layered inside joke.
Our National Bird will likely soon be the turkey, or the vulture, or the dodo.

> Do you realise that this is taking me back 50 years to high school?
Right, where we should have paid better attention.  ;)




> Are you trying to eliminate the effect or show it?
Eliminate it on all moving parts.
I figured if I could pre-calculate / predict the appearance of the effect, I
could just vary the number of frames rendered between clock 0 ---> 1 and get
something that would mesh well (ha!) with all the gear sizes.

> Also what frame rate are you encoding the animation? I think you have to
> take that into account too (also).
It's in there, since that's how I calculate the degree of rotation between
frames.

> Have you tried a test with a single wheel?
No - it doesn't take that much time to render the whole scene, so I just let 'er
rip.


> > 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.

It's easier to keep track of things that rotate by assigning a full 360-degree
rotation to a full clock cycle.

> > and
> > // ROTATION FOR ANIMATION
> > // Clockwise = Negative
>
> Widdershins! Dangerous!  ;)

I know, right?   I'm not the one who chose a Left-Handed coordinate system for
POV-Ray  :O

> 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 suppose I'm trying to correct 5 illusions at the same time, since I have 5
different size gears (assuming the spokes and teeth of the drive gear are
visually separate)

>I would
> either just concentrate on the spokes and let the gears look after
> themselves or greatly increase your frame rate.

I don't think letting the teeth look after themselves fixes the problem - I have
a narrow window to sync the rotation with the proper positioning.

> 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.
A fifth of a revolution would give me a full overlap of symmetry - it would look
like only the handle was moving.  I'd have to stick with a tenth of a revolution
or below to comply with the "1/2 distance" theory.

> 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.

Right, but that's a simple demo - the drive gear has to revolve 5 times (not 7
SMH) for the slowest gear to make one full revolution - no way around that.

I jacked the frames up 90, and most of it looks good except for the 3 15-tooth
gears.  I will keep at it.

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