A teacher stumping animation problem. Probably a simple answer.
In a recent class I had at school I had to animate a falling scaffolding. I'm not planning on being an animator so I haven't done much outside of what I've had to do for classes and I ran into an issue where if I rotated a scaffolding sections "skeleton" from the first bone on only one axis, that it would not rotate on just that axis but on more then one, swinging out between keyframes. I "solved" the issue by animating from the second bone. This worked well enough and the project didn't turn out half bad.
Here I have recreated this example of the problem. I created the bones and set a keyframe at frame 5. I then move to frame 15 and with auto key on, rotate along just the Y axis, shown with the yellow arrows. I expect it to rotate along just that axis, but in the middle image of frame 10 you can see it swings out before coming back to the proper position on frame 15.
I now have a character animation class and I am again experiencing this issue. The teacher supplied us with a .max file with a biped character in it and asked us to do a basic FK walk cycle. I immediately noticed that when I tried to rotate the arm from the shoulder it would swing out just like the scaffolding had. When I brought the issue to the teachers attention he messed with it for about 10 minutes, talking about how bizarre the issue was. As he messed with it I looked around and started noticing the issue on others characters and when I pointed it out he replied that the one he had done as an example also had the issue, but he had assumed he had just incorrectly placed a key somewhere. He then just got up and walked off, leaving me with still no idea what is going on.
I will greatly appreciate any light you guys can shine on this since the $1200 I pay for a class apparently doesn't cover it.
Thanks in advance,
Mike
Here I have recreated this example of the problem. I created the bones and set a keyframe at frame 5. I then move to frame 15 and with auto key on, rotate along just the Y axis, shown with the yellow arrows. I expect it to rotate along just that axis, but in the middle image of frame 10 you can see it swings out before coming back to the proper position on frame 15.
I now have a character animation class and I am again experiencing this issue. The teacher supplied us with a .max file with a biped character in it and asked us to do a basic FK walk cycle. I immediately noticed that when I tried to rotate the arm from the shoulder it would swing out just like the scaffolding had. When I brought the issue to the teachers attention he messed with it for about 10 minutes, talking about how bizarre the issue was. As he messed with it I looked around and started noticing the issue on others characters and when I pointed it out he replied that the one he had done as an example also had the issue, but he had assumed he had just incorrectly placed a key somewhere. He then just got up and walked off, leaving me with still no idea what is going on.
I will greatly appreciate any light you guys can shine on this since the $1200 I pay for a class apparently doesn't cover it.
Thanks in advance,
Mike
Replies
This will most likely screw up existing animation, so it's always best to set it before keying things. Keep in mind that different rotation orders work best for different situations.
To expand on that a bit, it'll depend on what axis you have point down a joint, which axis is up, etc. It also depends on what axes are the most important for a given joint... for example, you might want a different rotation order for the shoulders than the feet as they have different motions.
Whoops, you have to click the rotation button under PRS parameters to bring up the axis order. Sorry!
Another thing is, you can select the bone and alt+right click and freeze transform. This will add a list controller and zero things out.
In your original example, if you go into gimbal mode for rotation you can see that you're already gimbal locked before doing anything. That's bad. Zeroing it out will fix that.
Was thinking the same thing, but kinda depends on if its strictly a animation course, rigging course or a blend of both.
I mean soon or later an animator ought to break even a fool proof rig and screw it up. I just don't necessarily see the same person both rigging and animating.
I disagree, you dont even need to technicaly know how a rig was made to understand something isnt quite right after animating with it.
And also i wouldnt trust a rigger who never animated there rigs, they dont have to be amazing animators just keen enough to properly test there rigs.
And to the origional question, that seems like a euler filter (in Maya) fix, perhaps theres something similar in Max?
The other suggestions are good too, check/change rotate order, fi that doesn't help, try switching the curve interp type in either the preferences, or the graph editor or both.
Now while I have you guys, hopefully you can answer another question for me. As I'm skinning I"m doing small test animations to see the deformation of the mesh. I'm finding that Auto Key and Set Key aren't working as expected 90% of the time. Auto Key most often creates a key on the current frame but (when placing the objects first keyframe) it doesn't auto create a key of the original position at frame one. And Set Key most often does nothing. The school just upgraded to 3ds Max 2010 and that's when it started so I'm thinking it's that and a google search on the issue brings up mostly Max 2010 release notes and such.
And yea, I'm very unhappy with the instruction I've received at my school. I have the same teacher for an Action Script 3.0 class and our homework is to learn how to do something ourselves, and then come in and teach the class. So why is he even there? At any rate I'm only 12 classes from being done so I'm just trying to get through it at this point. You guys will probably be seeing me more often over the next year lol.
Thanks again,
Mike
Also the auto key and set key may only key the channels for the selected manipulator IE pressing set key with something selected and the rotation manipulator active may set ONLY a rotation key for that object.
In maya this is a preferences setting, but again, not 100% sure in max.
Before you start animating and while your still on frame 0 you can click the big Key button which will set a key for everything. Or you can right click the time slider <(0/100)> and choose to set keys for specific things.
Auto Key creates a key frame, but only one, at the current frame and nothing at the start. Something else I noticed is that the key frame Autokey creates isn't one of the regular colors for the type of transformation. The key frame is gray, which I've never seen before.
As it is now, with Auto Key on, I'm having to "manually" create keys by moving and rotating with snap on and then returning it to it's original positioin. It's very frustrating and making the project take a good deal longer then it should. Any help would be appreciated.