Vertexes moved by two bones (two vertex groups)

I’ve read through BlenderChar’s hand animation tutorial and I was wondering something about this passage:

You can add a vertex to more than one vertex group. For example the vertices that build joints (of fingers, wrist, elbow, etc.) could be assigned to the two vertex groups that are situated close to it. You can also assign vertices to deform with different strength. The default stregth is 1.000, but you can add vertices with strength 0.500 or less. The lower the strength value, the less deformation for that vertex. You can make a vertex deform 75% by one bone and 25% by another, or 50% by one and 50% by another. It’s all a matter of testing the deformation until you achieve the result you want

how do I alter this strenght? And more specifically, how do I alter this only for the part that is used by two vertex groups? This way an arm should have strength 1.000 to the Arm bone, but the wrist only 0.500, while the other 0.500 is taken care of by the Hand bone. (the arm is only part of the Arm vertex group, the wrist is part of both Arm and Hand vertex group)


  • Bentagon

few things

a vertex is deformed by a particular group, not the amount of influence of that group on that vertes, but the amount of influcnce of that group on that vertex relative to the total amount of influence of all the groups on that vertex. (a vertex that is influcenced 1.0 by two groups will be move half by each of them)

next, with your mesh selected, try choosing weitght paint mode on the 3d window header. Choose the bone group, and the weight to paint with, in the edit buttons. Also helpful to turn off soft and change some other paint settings (now also in the edit buttons)