I have a situation I need help with. I have done a dog cartoon character. I’m trying to get his jaw to open. I have weight painted his jaw to his jaw-bone.
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when I move his jaw-bone, his jaw seems to move only proportionally, unlike his lower teeth and tongue.
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can someone tell me what I’m not seeing.
Thanks
The usual cause of this is that the vertices that you have shown the “Jaw” weights for have weights also assigned to another bone. Try selecting each other bone on the rig, in weight paint mode and see if the jaw vertices are also weight painted for that bone. What happens is:
Vertices are painted 100% for “jaw”.
Vertices are painted 100% for “head”, for example.
You rotate the jaw bone, vertices are moving 100% for jaw but are kept still for head, hence the jaw vertices only move half the angle of the jaw bone.
The solution, clear all influence of other bones from the jaw vertices. Or, clear ALL of influences on the jaw vertices and then weight paint them for the jaw bone only.
Otherwise, if this is not the case, post the blend file and we can look at it.
Cheers, Clock.
Adding to Clock’s excellent advice.
You can turn on Auto Normalize to prevent problems like this. (Tool panel) Auto Normalize will take all of the weights from all groups on that vertex and make the value equal 1.00. Without this option on, red really has no meaning because a vertex can have 1.0 weights for more then one bone and blender will just interpolate the difference.
Be careful with this option. It works well for areas that have influence from only two bones, but it will sometimes take weights from the “wrong” group if there are three or more bones. (Shoulder/chest/arm is a common problem area) If you have more then two bones influencing an area, it’s better to manually change the weights in edit mode> n-panel >vertex weights.
Thanks for the help guys. I never did find another bone in the armature that had weight effecting the jaw. So I deleted the armature modifier (and all the vertex groups) and started over. works fine now.
it may have been because I had added the jaw-bone after the armature modifier had already been applied.
That’s exactly why you got the result you did. Your vertices for the jaw where already assigned to the head bone, then you assigned them to the jaw, hence what I said earlier applied.
Glad you got it sorted.
Cheers, Clock.