View Full Version : problem with up-vectors

Dan Wade
07 July 2002, 09:15 PM
I am just going through the basic tutorials for xsi2. Ive completed my entire rig for a character....but for some reason, my up vectors mess up!

I create a null and position it behind the arm. Then i select first arm bone and select the null behind it as the chain up vector...but all it does it flip bone (with the arm atached).

Any ideas
Ive even tried this from scratch just with a simple 2 bone setup and it still goes wrong??

Cheers in advance,

07 July 2002, 03:14 AM
A pop up box should appear when you apply the up-vector. There should be 3 offset fields; one for x,y and z. Try setting each one of these to 1 or -1 while leaving the other 2 set to 0. This should fix it. Hope that helps.

07 July 2002, 09:50 AM
I never seen the pop up box that you talk about the up-vector constrain, but I see that the bone's rotation degree can modify the position of the bones when I apply an up-vector.

Try to do some test with a chain,
you can note that when you apply up-vector to the blue chain, their bones rotate of -180:eek:

07 July 2002, 02:13 PM
sorry, my fault....I've been dealing with other constraints for the last few hours :surprised Ok, see image below, this will fix your problem. Simply change the roll perameter to 180 or -180, that should fix it.

07 July 2002, 03:20 PM
:thumbsup: You're right! I search it in Kine of bone, not in the joint! Thanks

Dan Wade
07 July 2002, 05:15 PM
That sorta works. But in the examples ive seen, once applied, a line appears from the first bone to the last, passing though the null (up-vector). This doesn't happen in mine?

07 July 2002, 08:11 AM
:shame: Sorry, in the image that i've attached, the orange line was an input for you to try you to do some experiments with upvector on the bones.

However, to see the line that represent the upvector contrain,
you must click on the eye icon on your views>Visibility options... (or Shift+S)>Attributes (in the pop up window) and check the Chain critical zone for selected or/and unselected objects:thumbsup:

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