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I'm using version 2.68a

I've created a face mesh and now I'm trying to setup some bones to create expressions. So far I have added one bone and parented it to the mesh as "envelope weight".

However the envelope falloff is not working, as all the vertices within the bone envelope move/rotate at the same rate.

I remember working with an older version of Blender a couple years back and bone envelope falloff would work fine. I don't remember the version # though.

Is anyone aware of this, is there a solution or a version where this is confirmed to work? Thanks!!!

irrlicht_ist_toll
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1 Answers1

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I too am curious about the proper use of bone envelope in Blender too. The falloff appears to not be functioning correctly. This may be a bug. As you say it used to work, so something may have changed that stopped the falloff from working as desired. I just double checked and what we are calling falloff is called 'distance'. I don't know if this name changed. I submit a bug report and see what happens.

Update: I have submitted a bug report and referenced this post, provided Blender files I used to test this too. It is definitely a bug, as the blender manual states the following: "The outside area, materialized by the lighter part around the bone, and controlled by the Distance setting. Inside this zone, the geometry is less and less affected by the bone as it goes away by following a quadratic decay." The quadratic decay appears to be what has failed. https://www.blender.org/manual/rigging/armatures/skinning/obdata.html#bone-deform-options

Bug report: https://developer.blender.org/T50392

Chris Lee
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    The bug was closed as it is not a bug. If you follow the link to the bug report you will see Ronan's replies.

    TLDR: Use multiple bones as a single bone will treat any influence as 100%. Check the multiply option in the Deform tab of each bone and add a corrective smooth modifier.

     – Chris Lee Feb 10 '17 at 13:48
  • Posting the relevant quotes here from Ronan, for easy reference:

    "The decay exist. But bones are not acting like hook modifiers.

    Weight groups are used by armature to set the priority of one bone upon another one. If vertex belongs to only one bone, there is no question : it follows the bone. If vertex is influenced by two bones, it follows one more than another according to weight.

    It works as is for painted weights or weights interpolated from envelopes distances."

     – Chris Lee Feb 10 '17 at 13:49
  • "If you try to use envelope to obtain vertex groups useable by armature modifier, you have to do it with a skeleton in rest pose. Then, you have to check Multiply option in Deform of each bone to use envelope to compensate bulges from these weight groups.

    Result should not be bad. But it can be smoother by using a corrective smooth modifier. In fact, corrective smooth modifier is so good that you can avoïd to create vertex groups and use only envelopes."

     – Chris Lee Feb 10 '17 at 13:50