Hi Pilou,

> Does normaly same numbers of segments in each object to blend?

Yes, that's currently a limitation of Blend, that you can only do it between 2 edges at a time.

I'd like to remove this limitation in the future, but for now to get a result between a cylinder and a box like you show there, you would want to select the cylinder's edge curve and use the Trim command on it with "Add trim points" to break that edge into 4 sub edges, then you would have a compatible edge structure on the end of the cylinder for blending to the box.

- Michael