Rhino 3D Modeling Process

Rhino 3D is different from parametric 3D CAD programs in the respect that there is no design feature tree. Since Rhino 3D is not feature-based, the line(s) or curve(s) for a surface are independent from the surface by default.

With that being said, however, there are different methods to preserve the building history of a 3D model. And certain parent/child relationships can be established and maintained when the design is updated. I can either 1) turn on Record History or  2) manage to separate curves/lines and the surfaces created from them into different layers.

 For method 1) turn on Record History:
Based on Rhino's help menu: the History command "Stores the connection between a command's input geometry and the result so that when the input geometry changes, the result updates accordingly. For example, with History recording and Update turned on, a lofted surface can be changed by editing the input curves."

When using method 2) with layers to manage the parent/child relationships, I will assign lines/curves to one layer and create a new layer. Then the new layer will be set as the current layer from which the new surfaces will be created. Next time when I need to update the sketch profiles in lines/curves, new surfaces will be generated from the updated lines/curves without interfering with existing surfaces.

As direct editing function is a natural way to create, edit and generate 3D models in Rhino 3D, it will require more efforts from me to get familiar with the 2 above-mentioned methods in maintaining parent/child relationship.