View Full Version : global and local rotate keyframes

01 January 2007, 08:29 PM

cause im really new to Motion builder so i have to ask a question that may seem ugly but i have to .. belive me... :sad:

i have a character in the MB and i want to keyframe some of the joints rotations... but when i keyframe one of the rotations ( for example Y axis) in global rotation mode, the key frames are generated for all 3 axis ( x, y, z) in other word, it's keyframe were made in local rotation axis that makes it hard to tweak ... i need keyframes for rotations be in global rotation mode not in local mode what can i do???


01 January 2007, 09:52 AM
You are mis-understanding the nature of global vs local.

They are simply two ways of looking at the same rotations, if you rotate on global, it follows the local rotation is affected because you are rotating the object.

Some packages, such as LW, have 3 ways of looking at a rotation, local, parent and global, all you are doing is changing your co-ordinate handling.

The easiest way to see this is if you create a cube, rotate it globally on one axis, switch to local and you will see the axis line up is the same.

Only once you rotate the object 'off-axis' does the difference between handling manipulations locally vs globally become apparent. It's just sometimes easier to rotate a joint say, by switching to local mode rather than trying to rotate it in global mode.

As I say though, the end result is the same.

01 January 2007, 07:12 AM

but you see, tha ankle for example has a non stright angle..
if you watch it in global mode the y axis is as always, perfectly perpendicular to the gird ... but in local mode ( in my case)
the x axis point towards the toe joint and relevantly the y axis makes angle to global y axis ...
meanwhile rotating Y axis in local mode isn't what i want .. i just want to rotate leg at the ankle point ... ( y in global )
and here the proplem arises...

01 January 2007, 09:40 AM
Yes, that is exactly right, read my previous post carefully.

It is two ways of seeing the same thing, one (local) is a rotation as "viewed" from the angle of the bone/item concerned, the other (global) is always in relation the the grid (global co-ords)

Think of it this way, no matter how you orient your character, the grid X.Y.Z remains the same, however, the X.Y.Z. of the bone is shifted based on what way it happens to be pointing.

This is absolutely standard and you cannot separate the two, AS I said previously they are not two distinct ways of editing, just two ways of seeing the same thing.

You should sit down and read some info in the manual and help files, do a few tutorials, it will all become clear.

01 January 2007, 09:03 PM
i think i 'v got lot things to clear the proplem for you ....

but good to know i am a maya user and after several years i think i know enough about local , global and any other relative stuff but let me be more specific..

is there any way to change keyframing mode in MB from local to global so that it reads in Fcurves ( Rotation (Gl) , not Rotation (Lcl) ???

01 January 2007, 09:28 AM
Ahh, no, I don't think so, I see where you're coming from now, you'd like the option for FCurves to reflect the mode you're in.

That would be very cool, but I'd imagine a total nightmare to think about coding.

Funnily enough, I am experiencing a similar situation, where, if I could edit in "local mode", it would make my data corrections a lot easier.

01 January 2007, 08:23 AM
Hmm, same thing for me here :) That's an eternal problem editing in FCurves with all the axes messed up...

CGTalk Moderation
01 January 2007, 08:23 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.