CATIA V5 – Geometrical Set vs. Ordered Geometrical Set

There is two methods of modeling in the Generative Shape Design (GSD) module, one uses a Geometrical Set and another Ordered Geometrical Set  . The methods differ considerably in approaching modeling.

The Geometrical Set allows different geometric elements to group into one set or more subsets, and to organize the tree structure when it becomes too complex or the tree becomes too long. You can put any element you want in a geometric set, where the structure does not have to be logical and does not have to follow the steps of making the model itself. The order of these elements does not have to be meaningful while managing them independently is not subject to any rules. This structure is very flexible and does not have to follow the design of the model.

The Ordered Geometrical Set is characterized by the following steps that determine the design and absorption of the elements. Here, creating an element creates a new object, and the previous elements are absorbed. The absorbed elements are not visible or available, as if they were "masked" by the absorbing element. In this set, the order of elements in the tree structure is consistent with the steps of creating the model. Unlike elements within the Geometrical Set, the Ordered Geometrical Set can be set as a Current (similar to the Part Design environment) to set the desired step in creating the model. All the elements that are in the tree structure behind the current element are not seen.

The following example shows the difference between modeling with one or another set.

In the new Part, we add the Geometrical Set, using the Insert / Geometrical Set command. We will create a simple Extrude from a previously created line. Next, we'll get the surface of Extrude with a flat YZ.

If we now want to re-utilize Extrude.1 and make it e.g. Offset, the system will allow us whatever Extrude.1 has already passed. With Insight into Parents and Children, we can see that two elements, Split.1 and Offset.1, were created from Extrude.1.

Now we will create a new part with the difference that we will do with the Ordered Geometrical Set. We also add it with the Insert / Ordered Geometrical Set command. We make the same Extrude from the line and bring it to the flat YZ.

If we now want to reuse Extrude.1 and make it Offset, the system does not allow us, so it warns us that Extrude.1 cannot select it since it is already absorbed by the Split.1 element.

Only Offset from the Last Element (Split.1) can be done here. In short, when we use the Ordered Geometrical Set, we have no way to reuse the already absorbed element.