In a shell feature creation, what does the direction of the arrow indicate?

In the context of creating a shell feature in Siemens NX, the direction of the arrow indicates the positive wall thickness. When you define a shell, it is important to communicate which side of the model you want to keep the material and which side will be hollowed out. The arrow visually represents this choice, specifically pointing toward the side where the wall will remain after the operation is complete.

By indicating positive wall thickness, you are effectively specifying that the material will be retained on the side the arrow points to, emphasizing the thickness that will be maintained. This aspect of shell creation is crucial, as it directly influences how the geometry of the model is developed after the shell operation is applied. Understanding the arrow's direction helps in controlling the resultant geometry and achieving the desired design features in the model.