you could possibly do a set driven key on the pivot point? i dont know how you would do that though, i dont see any option for objects unless you made a custom attribute then linked it via expressions to the pivot point and then used set driven keys on that custom attribute

i dunno how that would work though...

you could just set another control curve to pivot the object at a different point the same way you did it for the first.

so like... if you did a parent constraint on one control curve then do a parent constraint with another curve then you get two constraints showing up in the channel box for the object that's constrained.
then you can just key those (or use set driven keys or expressions)
probably a messy way to do it though... i dunno... no one seems to talk about good practice anywhere when it comes to rigging...

Thanks for the ideas Chirone...
If I understand you correctly, one problem is that you can't parent constrain something to two different curves (curves being the 'parent' or master).

I looked for attributes that change the pivot point, but in the list of keyable attributes, all I could find were things like 'rotate pivot translate x' or 'scale pivot y' which I have no idea what they do. I tested them and got very odd behaviour. As usual, my search in the maya help turned up no help. I'll keep playing around with different things, and maybe do some more rigging tutorials after the challenge is done.

if that were true then that would make it impossible to do what i'm doing for my transformer :D

i'll post a screen shot of what i mean when i get back home...

Oh... do you mean key the parent constraint to different parents at different times? On one, off on the other, then switch?

well you can parent constrain the same object to two different curves (unlike normal parenting) and in the channel box there becomes a new input, one of those inputs is related to the parent constraint which has under it the two constraints that oyu just made
and they have weights, so you can just key those weights

That's interesting, cause when I tried to do that, it came up with the error 'Object is already constrained' but I'll give it a shot when I get home.

Alright, I thought I was finished rigging the car, but thanks to Chirone's help, I spent some more time on it and got it to a much better point.

I don't know where the error came from before, because I was quite easily able to add two parent constraints to the same geometry. Then I used driven keys to switch the weights from one point of rotation to the other based on a custom attribute for my main control. Very nice :)

I also fixed up my idling control so it now idles away when I turn on my idling boolean attribute. (I wanted the car to move up and down very slightly) No manual animation for that, just added an expression based on the sine of the time. The extent of the motion needs tweaking, (it's going like a jackhammer) but it works.

Thanks again, Chirone!

Sounding interesting Stwert, I'm looking forward to seeing the finished short!

I've not really used expressions in mine, apart from two which was in the rigging stage, one for a knee lock so his knee doesn't go haywire when using a foot roll, and one for a forearm twist. I know that we're supposed to use them for this so hope that counts! lol

I've also gone slightly over the length limit now, mostly because I added a little title and end sequence bit to make it a little more "video" and not so much "clip", hope that's ok....

Keep it up mate, hope you get all you want done by the end of the month!

Small update. Getting going on rigging my robot guy. Added blink attribute and some other stuff. Was hoping to finish rigging it tonight, but spent more time tweaking the model, even though it's not a polished entity. Ah well, I'm not letting it bother me too much. What's the point of having a hobby that stresses you out, right? :p

I'll have some animation soon, I promise :D

And the fully rigged bot. Actually, not quite fully, got a couple attributes to reconnect, but pretty much there. Reasonably happy with how it turned out. Let's see if it holds up under animation conditions! Cause it doesn't matter how much fun I had rigging it, if it isn't easy to animate with, it's pointless! :p

If you haven't noticed yet, I work better under the shadow of a deadline. I envy you dango... haha.

Nice, I guess you didn't really have to do any weight painting as he's a robot, did you use a Rigid bind?

Hope he's good and animation friendly for you!

Mostly just used parent constraints for the bones to the parts, but I did use smooth bind on the springy base part, and had to do a bit of tweaking.

I thought I was done the rigging, but I added a couple more controls and ensured that I could scale both the car and robot rigs so that they'd fit in the scene. Finally I created character sets for them both, so I should be onto the animating finally!

Been busy with an evening composition course that I registered in. Looks interesting and promising so far.

On a somewhat related note, marking menus are awesome. I made this one to quickly get to all those little windows and editors that somehow take forever to find in the Window menu > General, or no wait... animation... Big time saver!

Here's the assembled scene... sorta. I was going to do an ambient occlusion render, but it came out black inside the enclosed space. Anyone know of a quick way to do amb occ inside a room? I don't suppose adding a light would help? Probably not, since I tried that. Anyway, just wanted to quickly post the idea.

Yeah, texturing is still kind of a grey area for me....

Hahahahhaa....:p

K, going to bed now.