That gives the same result as not using a skin wrap at all and just diving straight in with a skin modifier, which is a complete no-go because the sheath mesh moves far enough in the morph that the bones it'd be skinned to are way further along the tube and it'd get completely the wrong posing, like so:
You wouldn't need to counter animate anything if it was rigged right. I'm slightly surprised Eric's fix works - it probably won't if you make explicit vert to bone assignments (now I think about it, that's why the skin wrap doesn't) but I can see how it would if you use envelopes.
Hello polycounters. Here's a situation I'm not sure how to deal with, I have a tube that I'd like rigged to a lot of bones so that it's nice and flexible, and I want it to have a sheath around it that uses a blendshape to scrunch down along the tube's length, but I'm unsure of how to get the sheath blending along with the…