Gordon Surface for Curve Networks

With CAESES 4.4.2, we’ll intro­duce a new surface type, the Gordon surface. This surface can be seen as a com­ple­men­tary tool for sit­u­a­tions where you would create Coons patches in CAESES. So, what it does is, allowing you to create a surface patch based on a given network of curves. This set of U- and V‑curves needs to be ordered for gen­er­at­ing the para­met­ric surface.

We’ve had several feature requests in the last couple of months where users wanted to create a smooth surface patch­work based on a skeleton-like setup of curves. In these sit­u­a­tions, CAESES users would create a patch­work of dif­fer­ent surfaces, such as fillet surfaces, Coons patches, ruled surfaces, etc. However, the Coons patches, as an example, do support tan­gen­tial infor­ma­tion for smooth tran­si­tions only if the adjacent surfaces are given — which is not the case during many modeling tasks. Fur­ther­more, it is often not really handy and rather tedious to create loads of single patches, even if things are auto­mated using feature def­i­n­i­tions.

Gordon Surface in CAESES

That’s where the Gordon surface come into play. In CAESES, the Gordon surface has two input attrib­utes: Curves U and Curves V. These curves need to be sorted, and they need to inter­sect at the loca­tions where the curves are crossing each other. 

Once you have created such a Gordon surface, you are still able to control the network and the surface follows your changes (well, not a big surprise for CAESES users). 

The para­me­ter­i­za­tion of the input curves is an impor­tant aspect to suc­cess­fully create a nice Gordon Surface. In some sit­u­a­tions, the para­me­ter­i­za­tion needs to be changed by using the para­me­ter­i­za­tion attribute of curves. If inter­po­la­tion curves are used as input, there is also the new option to change the inter­po­la­tion method, which implic­itly changes the para­me­ter­i­za­tion and helps to further fine-tune the surface results.

Curve Network Creation

There is an addi­tional feature in the surface more menu, to create Gordon surfaces based on four input boundary curves. This creates a patch and a network of U- and V‑curves between the bound­aries. The inner vertices, i.e. the inter­sec­tion points, can be moved to modify the shape. The feature option­ally creates design vari­ables, to slightly move the inter­sec­tion points in normal direc­tion. Such small changes can help you to fine-tune complex shapes during auto­mated studies and shape opti­miza­tion runs.

Exper­i­men­tal Phase

This new surface type can be found in the surface menu of CAESES, and is still a first version that is sort of exper­i­men­tal. We are col­lect­ing your feedback, to find out whether it sat­is­fies most of our users’ needs. In par­tic­u­lar, we are curious to know where it is helpful in your specific appli­ca­tion, and what is still missing. Try it out and send us your feedback!

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