To me, your question is like asking, are there such things as trees, or is it just the way we perceive the world? "Tree" is a word that is used to describe physically existing objects that meet the criteria used to define what a tree is. "Pattern" is the same.
Of course, it gets a bit more complicated when non-physically existing concepts are considered. A particular tree is perceived when physically existing light waves bounce off a physically existing treelike object and strike physically existing sensory receptors. A conceptual "model", if you will, is formed by the organism that is perceiving the tree. That concept of the tree is non-physical and exists inside the mind of the organism. A tree also exists physically, outside of the organism's mind. The conceptual and the physical trees both exist, but they are fundamentally different. Even if the conceptual model is "accurate" it is not an actual tree.
Patterns undoubtedly exist, and they are undoubtedly based on physically existing cues, but they may be "inaccurate" interpretations (like a tree that is thought to be alive and organic when it is actually a man-made construct of fiberglass and silk), or they may "accurate".