Rigger tips: Aligning Bones
Sometimes getting our bone chains aligned can be tough and cumbersome. As you probably already know there is no Local coordiante system for bones in Edit Mode, so we only have the Global coordinates to work with. This is a good reason why you always be happier aligning your legs and arms at least to one orthogonal plane, the XY, ZY or ZX plane.
Here are some tricks to help you keep your bones aligned.
Use Cursor Snapping and Cursor Reference Mode. It is very helpful and many operations couldn’t been done without these. You can always snap the cursor at a bone chain root or tail using SnapTo (SHIFT+S) tool. Once there, you can use Cursor Reference ode to align bones by scaling them in some global coordinate. Watch an example here.
How to correct homologue bone loc/rot ?. If for some reason the homologue of a bone (.L o .R), got misplaced in rest position, you can always use X-Axis Mirror button, and select the bone, press G and cancel immediately. Doing this will reset the homologue to its right location/rotation.
How to scale along main bone axis ?. To do this use the cursor at the root and scale up/down using the Cursor Reference Mode (see above). By doing this you’ll keep your bone’s orientation and root’s location intact.
Howto set a bone in the middle of another bone ?. There are a couple of ways to do this. You can duplicate the original bone, locate cursor at bone’s root and scale to 0.5 as debscribed above (using cursor as reference). This will put the tail of the bone at the middle of original bone. Now you can use Cursor and snapping to put a new bone there (and delete the scaled down bone). In earlier Blender versiones you can do this by selecting both root and tail and using “cursor to select” in the Snap menu.
How to align a bone in the direction of another bone ? By combining all of above you can align some rebel bones to the direction of precedent bones in a chain. Check this videotutorial as a summary of all these.
Hope these tips help you out a little. More to come.
January 18th, 2009 at 11:49 pm
[...] Now a short discussion about B-Bones. B-Bones will look curved only in Pose Mode and only if their children are rotated. So we are going to add children to our SDEF bones. Ideally these children should be aligned to their parents. There are many ways to create aligned bones and I have explained these methods before in this same section. [...]