Fold a sheet of paper horizontally and then diagonally

Hi

I have a problem to animate a sheet of paper. I want first bend it horizontally - unfold it and then bend it diagonally. Is this possible? I tried with VertexWeightMix and Mask Vertex Group without success. I tried also different bone structures.
How does I set the vertex weight of a group to zero for some frames?
Or maybe there is another easy way to animate this.

How I can upload the blend file as a newbie?

best regards
Julian

Hi, you can do this with shape keys. make sure you have at list one edge flow at each side of the foldes.

Thank you. How i can use shape keys without stretching or shrinking edges?
What does you mean by edge flow?

That didn’t work.
This is bones setup works fine for me, i used follow rotation constraint for the extra bones.
Here is the file:
Folding with bones…blend (818.8 KB)

And here is the animated file:
Folding with bones.Anim’.blend (828.1 KB)

Thank you Digitvisions
That bring me a little bit closer to the diagonal folding. How I can tell the diagonal bone to follow the rotation of the straight bone? Copy rotation doesn’t work in this case.

Folding diagonally.blend (841.5 KB)

Thanks again.

It works now without the bone constraint.

Folding diagonally.blend (844.5 KB)

Best regards
Julian

I have got the rig to work but you will need to adjust the weights.
file:
Folding with bones.1.blend (850.0 KB)