super basic rotation help - (yeah, having a "stupid" moment)

[andrewjohn81]

I don't animate often enough and am feeling pretty stupid.

I have an object and need to rotate it from the camera down to the ground. No problem, but then my coworker (my client) wants the object to rotate around axis a few times before it gets to the ground.

I prefer doing any rotation animations on their own local axis. So why isn't that working?
I animate backward in most cases, so I have the object on the ground first, set a key down a timeline a ways, then align it to the camera and set a key.
At this point I would think that in order to rotate the object I could just rotate around the Z axis and it should spin. But no, it spins all Over the place. It's like at any given point in time it's using world coordinates instead of local. If I spin it in place it looks great, but the animation doesn't work out that way.

Yeah, a way to solve it would just be to add yet another dummy in between and rotate that. In fact, in order to move on, that's what I'll do.

But can someone help me out and give me the more simple answer of how to do this in max? I thought maybe I had to change controller types or something, but didn't see anything regarding that in the help.

I know this is going to be one of those moments as soon as I see the answer I'll just feel like an idiot. But oh well...That's how you learn right?

[glyph]

you need to change the position /rotation controller from euler to xyz - but as you say, linking to a dummy is more controllable

[andrewjohn81]

I'm still not seeing that option. the only controller I see to change is "Euler XYZ" which is the default that didn't work, linear rotation, smooth rotation and TCB rotation, as well as a bunch of others that are more conroller based.

I guess i just don't understand how things work in Max. It always seem that they try and make things easy for people who don't know what they are doing, thus making it quite difficult for those who do.
Granted, I'm on the list of those who don't know what they are doing i suppose. I learned how to solve all these types of issues in Maya, but none seem to translate to Max.

[glyph]

oh hell got my nomenclatures muddled - its TCB that does the weird rotations

Euler xyz is the one to use - but you probably need to reset the pivot of the object being rotated first
I'm guessing the pivot is not aligned as you'd expect

[andrewjohn81]

The default is Euler xyz and it already was using that controller. I'm not sure why it acts that way.

Here's another funny one, maybe there's a bug? I added another object to control the rotation I want. I rotated Only Z. It screwed up in the same way. It wobbled to hell and even twirled around after a couple rotations.
I wanted express my unhappiness to a coworker and showed him what I did after undoing it. Then it worked fine!?! It seems it sometimes works, and sometimes doesn't.
Seriously, I have no idea how I could have done it differently once, and differently the second time, so it Really seems like a bug.

I set a key at 0, then set another key at 60. I open the curve editor, select rotate Z and changed the number to 1280 (just picked a randomly large number). It wobbled all over the place.
I hit undo a few times, then did again for my coworker and then it looks fine. That object only rotates in Z direction, and the other animation is otherwise unharmed, which is what I wanted in the first place.

Very frustrating. I'm sure it's something I'm doing "wrong" but it's still frustrating since I can't figure out what it is.

[Da_elf]

im not entirely sure what you need done or i would have given it a shot

[andrewjohn81]

well, that's the thing. I did it once, it didn't work. Then I did it again and it worked fine. I feel like Max's rotation only works under Very specific order. I wish I just knew what was going on behind the scenes a bit. I've always been very confused by Max's coordinate space system. I much prefer that of Maya's (but that's probably just because that's what I learned originally).

[SnipeyX]

The explanation is a bit hard to follow, maybe upload a scene?

There are a couple things factoring in here.

When you are looking at the curve editor, even if your coordinate system is set to local/view/etc, animation is always done in parent space, so the values you see there, and the axis, etc. are all relative to whatever the object is a child of.

Another factor could be your axis order. In the command panel, go to the motion tab, expand the PRS parameters rollout and choose the rotation button. Under that there should be a euler parameters rollout, and there is a dropdown menu for axis order. Depending on the type of rotations you are doing, you may need to change this. What happens is each axis is rotated in order, so if your order is XYZ, then as you rotate around X the Y and Z axis move. This type of thign leads to gimbal lock.

I would recommend a hierachy of point helpers to do this anyway, it's the most straightforward and flexible.

[mike_kennedy]

I second the point helpers. Car rigs are made much easier using helpers....

[simmsimaging]

It is the euler axis order probably. I had this exact problem a little while ago and some of the guys here helped me solve it (SnipeyX being one of them )

http://www.chaosgroup.com/forums/vbu...tation+problem

b

[andrewjohn81]

perfect, so it's just axis order.
Another thing I found out. you have to set that up prior to doing any animation

I'd solve that in Maya by grouping the object to itself, creating another set of nodes, then locking and hiding position and rotation x and z (maya's Y up).

I'm actually looking to solve the same type of issue in max and wonder how you guys do this. It seems pretty clunky in Max so far and I can't figure out if there's a better way.

I've got a camera move. I'm happy with it. Well, now i need to rotate around the object's center. In Maya I'd just group the camera to itself and move the pivot of that group to the object center. The I just rotate in up-direction to move around the object. I honestly hate the way Max groups because you have to open the group node otherwise it will set a key for every single object within the group. That and you seemingly can't walk up and down parent child relationships within groups.

I tried creating a dummy, moving it to the location i want, then linking the camera, but it moves. I honestly can't figure that out, but it moves. IMO it shouldn't. But it does. Anyone know why if you have animation on one object, create another object, move it, then parent the first object to the new one the first object moves?

I hate to sound like I'm complaining a lot. i'm just trying to get a grasp of how this stuff works in Max.

[SnipeyX]

Don't use groups. Yuck. Yuck in general, but double yuck with animations.

Is your first object parented to something (or grouped?)? I just created a helper and linked my camera that had existing animation to it, and my camera animation didn't change. This is the right workflow, we just need to determine what is causing your movement. Have a reduced scene you can send?

I know there are situations where things will move based on hierarchy changes, but not sure what that would be out of context.

Like I said before, animation is always parent space, so by changing the parent object (from world to a node) or node a to node b, your values in the curve editor will be changing (because 0,0,0 is now in a different location), but your object should remain in the same world position in most cases.

You're not complaining, just asking questions, no prob.

[andrewjohn81]

hey no problem. Here's the process I used that I expected to work:

I've got a teapot I wanted to zoom into so I quick made a camera and zoomed on in to the object to the left side. Then someone comes and says, "hey, lets keep that camera rotating around." So I create a dummy centered to the object to kind of act as a "look at" point. Now I link the camera, with current animation to the dummy and add some rotation.

What's that? The linked camera doesn't match anymore? Hmmm. I'm stumped.

In my file I actually ended up using a group. I know, I hate them too, especially for animating (although they are awesome in Maya for this purpose). But it's all I can get to work.

I threw together this scene so you can see what happens. I've got original camera, then a copy of that that I linked to the dummy. The starting positions are the same, but that's it. They go their own happy way in different directions as you scrub the timeline.