I'm trying to make an odometer that behaves like a real mechanical odometer. Each dial needs to advance one number when the previous dial makes a full roatation. Setting each dial with an incrementally smaller spin modifier means the dials are constantly moving, which I don't want.

The attached file shows what I'm trying to do and what I've been able to do so far, but getting there is a pain in the butt. The dial on the right is constrained to "shaft" in the Motion tab with at -180° to start, then rotated to 0° at 15 keyframes, then rotated to +180° at 30 keyframes to achieve a full 360-degree rotation. The next dial is keyframed to move 36 degrees  when the previous dial makes a full rotation.

Does anyone have a better way of doing this, or know an easy way to loop each dial once I've keyframed a full rotation? I'm sure there's a good reason Carrara only works in 180 degrees, but right now I can't think of it. I'm about to lose my mud here!

Thanks in advance!

What version of Carrara are you using?
If it is V6 you can change the rotation controler from quartermon to angles and then key in the exact rotation without any intermidiate keys.

wayne k
guam usa

Almost forgot  - you could automate this with the "Cognito" plug-in from Digital Carvers Guild.
(digitalcarversguild.com)
You would make the first ring the "motor" and drive the rest of the rings rotations off from it using the "gears" linkage - with only 1 keyframe.

That is about as easy as it is going to get.

wayne k
guam usa

You'd think some things would be included, but there's always a catch - isn't there? I'm curious about this puzzle too. (Might be useful in the future.) I wonder if there's a way to solve it with whatever comes included (5.1 pro?).

Now if there's a way to make the timeline sequencer do looping...  Hmmm...

Thanks, wayne, for the suggestions. I downloaded the trial of Cognito, and I can't figure out how to make it do the "triggered" movement on the subsequent dials. Is there a way to have that kind of timed -- rather than constant -- motion with Cognito?

I also downloaded the trial version of Carrara 6, and could upgrade from 5.1, but don't understand how to change angles to achieve a loop-able 360-degree rotation. How would I accomplish?

Thanks again.

http://3dsplash.com/WayneK/test/Draw-tmp/spin.mov

 

Before I posted the first time I did a quick test to see how cognito would work and

it is easy to set up a pretty accurate simulation.

It rolls up smooth like a car odometer would.

I'm thinking it should be possible to get it to pop the next digit instead, there are options for offset and phasing of the driven object. I'll take a look later today when I have some time.

 

 

To get 360 degree rotations in v6 you select your object and under Motion tab in the properties tray expand the motion section and the Rotation controller will show up.

Change the mode from quartermion to angles.

From there you can type in the total amount of rotation. Even values higher than 360.

 

wayne k

guam usa

 Nice Wayne. :D

not bad, wayne!  do the wheels all move continuously in an old-style odometer, or do they
suddenly click over at each decadal change?  I dunno, on account of  I've never watched one
change.

Looks like I am not smart enough to get Cognito to snap rotations.
The phase and offset options are for linear changes and not rotation.

Doing it by hand is not so bad, you only have to set 10 keyframes.

Use the spin modifier on the first wheel, set it to 1 revolution per second.

Keyframe the second wheel on each second time mark to rotate 36 degrees (using "angles" as the rotation controller will make them cumulative) out to the 10 second mark.

Set the tweeners between each key to "discreet" to have the rotation snap & not roll in.

Once you do the second ring you can duplicate it however many times you need to fill your odometer and then just offset the copied keys to have the digits snap at the right times.

 

http://3dsplash.com/WayneK/test/Draw-tmp/spin-2.mov

wayne k
guam usa

Thanks again, Wayne, for the tips. I upgraded to Pro 6, and (now that I know where to find them) the angles rotation mode is doing just what I need. I can now duplicate and retime keyframes to accomplish the task.

http://www.sparrowhawke3d.com/

Might some of the free plugins of Jeremys be of assistance for this sort of exercise?