Rotation with reference to translation question
 

how do you set up a cylinder to rotate when you move it like a wheel would rotate in real life? I'm assuming you would use the motion tab to add a rotation constraint, but i can't figure out which constraint to use or how to use it. any help would be much appreciated.

quite simple actually.

first rotate the wheel so that it is in contact with the surface that you wish to roll on. Then with the (autokey or animate) button turned on drag the wheel in the direction it will move. let's say it goes 0-100 and travels 50 feet.

Now go back and select the key mode and every say 5 frames rotate the wheel 90 degrees in the Z (depending on which axis it should rotate around)

quite simple to figure out, talk to me if you need some more help.

look in the tutorials...

there should be one about keyframing. that's what you need to learn about.

to make it short, keyframing is basically making a frame, then going to another frame and making a change, then letting 3ds max fill the frames in between.

*jeremy

Oi, that's not what i mean. hhhmmm, let's see how to describe this. i wanna be able set up a constraint that says whenever you translate in say the X-axis, rotate so-and-so degrees for each unit moved. All this without actually creating an animation timeline or keyframes. well, i saw it done in Maya so maybe it's not possible in MAX.

to my knowledge it's not possible...but maybe someone else could help you out. My only guess is that something like this would be under the motion panel.

Alas, without plugins you can't get MAX to do this automatically. Going to have to keyframe each bit individually, I'm afraid, so break out your calculator and start crunching the numbers.

Rotate along path
 

The only way I know of to do this in Max is to use a Maxscript plugin (freeware) that will automatically roll a ball or wheel along a spline path.

The plugin I have used is Roller from HABware (http://www.habware.at/duck4.htm). This is freeware, and is supported by Max 4.x. I have not tried it yet with Max 5, but it should work.

Good luck!

ok i'll check that out.

Arigatoo Gozaimasu

MAX 5 is more powerful than you guys think...

reactor* now has a "toy car" system, that will take care of animating the wheel rotation, plus many other motions. It might be confusing if you've never used reactor before, but if you want details about the system, see Chapter 8 of the reactor reference (Pg 49)

reactor is awesome, I think. Animators should use it. Sadly, I won't work on an animation this season...

*by discreet

hey suneet thanks for the reactor tip, that actually worked.

but you're not making an animation this year....can you elaborate.

Oh, my team is sort of short on real engineers, and I managed to get handy with Inventor over the summer. So I'm doing CAD work for robot systems instead of an animation. In fact, we don't plan to submit one this year. ::shrugs::

OK, so basically Reactor can do wheels. What about timing belts/ treads/ chains in loops? Is there an easy way to maybe IK them to the wheels so that they'll rotate as well?
Just curious, in ne1 knows ^.^;; thx!