Creating Patterns

[Cgav34]

What software do y'all use to create 3D patterns/objects?

I'm an intermediate graphic designer, and can use Adobe Illustrator to create a lot of objects, but have trouble creating rounded, 3D ones like this:


Most of what I can create with Illustrator is "stair step" 3D, where flat layers are stacked on top of each other (if that makes sense). I don't mind purchasing objects, when I can find them, but I'm unable to find objects for many of the projects I want to do.