Bone Creation Starts off in Gimbal Lock

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  03 March 2013
Question Bone Creation Starts off in Gimbal Lock

I am studying rigging and have already ran in to a problem. When I create a bones for the legs or anything that is vertical I usually go to the Front/Right/Left viewport and create the bones. When doing so the bones are automatically created with the gimbal rotation in gimbal lock.



I tried doing some research and reading about this but surprisingly there is little info regarding this issue. I can find tutorials on Gimbal lock that tell me to do things like change the Axis Order

But when doing so this causes my bone to rotate to match up with the axis. So instead of the axis changing for the bone the whole bone rotates to match the new axis which does me no good since i have to manually rotate the bone back in place.

I also tried affecting the pivot and rotating it to the correct gimbal position but this destroys the bone by squishing it.

My main goal is to find out if there is a way to create a bone and it not automatically be in Gimbal Lock or how to fix Gimbal Lock without moving/rotating the bone.

Any help would be greatly appreciated, thanks!
 
  03 March 2013
Another thing I have tried is to reset the xform. This seems at first to fix the problem but it also creates more problems. When i reset the xform for the parent bone all the children bones shift/rotate their position to match the new gimbal rotation which destroys the rig.
 
  03 March 2013
The gimbal on these bones is typically harmless because you are going to be using other controllers to drive their motion. You really only need to worry about it on object you will be keyframing/interacting with.

But a couple of things you can do.

1. Use Freeze Rotation or Freeze Transforms (which only does rotation and position, not scale.) But don't freeze until all your bones are in their final positions. I typically don't do this because usually these bones will have an orientation constraint and ....(see first paragraph.) I do Freeze my animation controllers.

2. Create another bone before creating this bone. I saw Paul Neale doing this in an older video. I think he did it to avoid some kind of dependency loop, but I don't' do this because game rigs need to have a single hierarchy skeleton.
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Juan Martinez | Blog | Animator
 
  03 March 2013
Originally Posted by martinez: The gimbal on these bones is typically harmless because you are going to be using other controllers to drive their motion. You really only need to worry about it on object you will be keyframing/interacting with.

But a couple of things you can do.

1. Use Freeze Rotation or Freeze Transforms (which only does rotation and position, not scale.) But don't freeze until all your bones are in their final positions. I typically don't do this because usually these bones will have an orientation constraint and ....(see first paragraph.) I do Freeze my animation controllers.

2. Create another bone before creating this bone. I saw Paul Neale doing this in an older video. I think he did it to avoid some kind of dependency loop, but I don't' do this because game rigs need to have a single hierarchy skeleton.


When you say "you are going to be using other controllers to drive their motion" Are you saying that I will be using Helpers? So if I understand correctly, I should Parent from bone to Helper?
 
  03 March 2013
Originally Posted by Bryan3D: When you say "you are going to be using other controllers to drive their motion" Are you saying that I will be using Helpers? So if I understand correctly, I should Parent from bone to Helper?


Yes to the first question, and no to the second.

We artists are visual people, so I made an image...
(In case you come from another 3D package, Link and Parent mean the same thing in 3ds Max.)

https://dl.dropbox.com/u/2904948/Tu...Controllers.png
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Juan Martinez | Blog | Animator

Last edited by martinez : 03 March 2013 at 06:02 PM.
 
  03 March 2013
Do not reset the xforms on bones. The bones are only in gimble because of their orientation in world space. Once the bone is linked into the hierarchy the parent orientation changes and so will the point of gimble. Make sure that objects that are to be animated in rotation have a parent object that is in the same orientation as they are at the starting angle.

This will make that easier to do.
http://www.penproductions.ca/scripts/mGroup/mGroup.htm
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Paul Neale
http://paulneale.com
 
  03 March 2013
Thumbs up

Thank you both, this has helped immensely.
 
  03 March 2013
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