Suggestion for handling hinges?

As you well know :wink: … I need to correctly animate a number of machines, which have hinged or pivoting parts. The pieces are naturally constrained to only a limited range of motion, perpendicular to an axis that is not necessarily neatly-oriented along X,Y,Z.

I am using armatures throughout, generally as described in the Rigging Mechanics tutorial at http://download.blender.org/documentation/html/x5897.html (mandatory reading for those who are interested in this too).

I’m finding that it’s critically important that the armature be positioned precisely at the center of the object, but I’m still encountering situations where the armature that’s supposed to move a lever winds up twisting it as well… in other words, a lift in one dimension “rocks it up on its side” whereas in real life the hinge-pin would prevent such a torsional movement.

I’m compensating for the problem somewhat by creating Empties and moving those. But… I’m wondering if there’s some constraint feature that I am missing.

You could probably use Lock Track constraints, they do wonders for that kind of job.

Martin

I’ve seen that constraint-type, and I guessed it might be useful, but in my version of the documentation http://download.blender.org/documentation/html/x5596.html, this constraint-type is undocumented!

Whuduzitdo?

It’s like a Track constraint but one axis is held in place.

Martin

theeth, you should be more arrogant (like me) and state: “BTW, I coded this constraint!” :wink: