Shape keys won't work with vertex group

I’m doing a tutorial here: For the shape keys, he shows how to use a vertex groups of the left and right sides of the head. So first I made shape keys with x mirror on in edit mode ,so both eyelids would be affected by the left shapekeys. Then I put each left shape key to the maximum, and created a new shape key for the right side. Then I assigned the left vertex group l for the left eyelids and the right vertex group for the right eyelids. But the right eyelids don’t respond when I move the value slider to the right. Does anyone know why my right vertex group is not working for the right eyelids shape keys.

For the right side of the mouth, I used the shape key menu, new shape key from mix, and mirror shape key. So I can probably do the same thing for the right eyelids. But I would like to know what I am doing wrong using the vertex groups anyway.

Blend file:

Not much wrong there, perhaps bit confused with the order.

There is shape key for both sides but the left side is then set to be limited by the left vertex group. If you want to create new shape that would then be limited by the right vertex group, you can’t make a new shape from one that is limited for the left side and then limit it with the right side too. That results to a shape key that doesn’t do anything. Instead

  • select the shape you want to create a new shape from, remove the left vertex group limit and put the value to 1
  • new shape from mix
  • rename to .R
  • put left vertex group limit back to .L and assign right vertex group to .R

Or you could do it like you’ve already done with the smile

  • select the shape you want to create a new shape from and put the value to 1
  • new shape from mix
  • mirror shape key
  • rename and test the values

That doesn’t need the right vertex group for limit because it was created by mirroring the left one but it will still work if you put it there.

Thanks for responding. It makes sense. I tried it on one right eyelid shape key, and it worked with the right vertex group. I’ll have to watch that tutorial again. I don’t recall him going to the menu for the “new shape from mix”. But he went fast, so maybe I missed it.

Yea, the default for hitting the + button must have changed at some point. Operator for that gets a parameter from_mix=False while new shape from mix uses the same operator and the parameter is from_mix=True. Would be handy to have a hotkey that toggles that parameter when hitting the + button (like ctrl or shift+ lmb click) but doesn’t look like it has one. Can always assign a new hotkey for new shape from mix though.

That explains it. Because I went back to the video, and all he does is select the plus button (which in his version of Blender must be new shape from mix=True) It’s no big deal to use the menu, but if I had known this, I’d have saved myself a few frustrating hours. Anyway, it’s a great learning opportunity…I don’t know anything about hotkey assignments, though.