Leaves and flowers are still mostly curvy. I can't think of anything soft that has straight lines meeting at sharp angles. Rigidity is physically necessary for

Leaves and flowers are still mostly curvy. I can't think of anything soft that has straight lines meeting at sharp angles. Rigidity is physically necessary for maintaining that shape long term. On the other side, you rarely see rocks with extended round parts meeting at sharp, concave angles. A lot if not most things that look like that are soft. It's not a perfect correlation, but it does seem like a real one to me.