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Dumb Question #437455018-coupling motions

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```....and a delurk post while I'm at it, too...

Basically, how would I go about making the motion in one direction a
function of motion in another?

Simplest eg. : say I have an object which moves erratically up and down an
inclined plane. Its x and y-positions are related through the most
lobotomised of trigonometry, and it'd be great if there was somewhere in
layout for me to punch in,

y=x*tan(angle of incline)

so I could then just worry about sliding the object back and forth along the
x-axis, and layout would know to make the object's y-position whatever the
equation says.

This sort of thing would also come in handy when animating mechanisms for
which IK won't suffice, say for something like a reciprocating piston
engine; the height of the piston and the pitch angle of the conrod are all
functions of the phase of the crank. Is there a features which lets me
couple things this way? The value of this degree-of-freedom of that object
is equal to such and such a function of this other degree-of-freedom of that
other object?

```
 0

```Expressions.

You can do a lot of this with the simpler "expression in a can" plugins,
like Follower (which I think is what you want) and Cyclist, and so on.

I have encountered a small bug with follower where scenes do not load back
to the same settings they had when you saved them, but otherwise, it is
pretty cool...

"Intact Kneeslider" <intact.kneeslider@start.com.au> wrote in message
news:bp1nh9\$1j3gol\$1@ID-190912.news.uni-berlin.de...
> ...and a delurk post while I'm at it, too...
>
> Basically, how would I go about making the motion in one direction a
> function of motion in another?
>
> Simplest eg. : say I have an object which moves erratically up and down an
> inclined plane. Its x and y-positions are related through the most
> lobotomised of trigonometry, and it'd be great if there was somewhere in
> layout for me to punch in,
>
> y=x*tan(angle of incline)
>
> so I could then just worry about sliding the object back and forth along
the
> x-axis, and layout would know to make the object's y-position whatever the
> equation says.
>
> This sort of thing would also come in handy when animating mechanisms for
> which IK won't suffice, say for something like a reciprocating piston
> engine; the height of the piston and the pitch angle of the conrod are all
> functions of the phase of the crank. Is there a features which lets me
> couple things this way? The value of this degree-of-freedom of that object
> is equal to such and such a function of this other degree-of-freedom of
that
> other object?
>
>
>

```
 0

```"Tony Gilchrist" <tony.gilchristNOSPAM@gnb.ca> wrote:
>
> Expressions.

You won't have to be the world's only psychic 3d artist to predict what my
next question is going to be... :)
(no need to answer just yet... let me sweat for a day or two trying to work
it out for myself; serves me right to have plodded on with a half-baked
understanding of LW for as long as I have)

> "Intact Kneeslider" <intact.kneeslider@start.com.au> wrote:
>
> > ...and a delurk post while I'm at it, too...
> >
> > Basically, how would I go about making the motion in one direction a
> > function of motion in another?

```
 0

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