The original Chrysalis/Ridgewing grill CAD model consisted of a “Bold” grillwork of major load-bearing tendrils with variable rounded triangle cross-sections, and a “fine” grillwork with a fixed 2mm x 2.5 mm vertical oval cross-section. It turned out that the fine grillwork was too narrow to die-cast, so a new grill design had to be created that not only lacked the problematic fine features, but which also captured the original grill design’s aesthetic.

The model is first planned out as a flat sketch made up of individual tendril paths, which are later projected down onto the swoopy surface created earlier that gives the grillwork its feminine shape.

In such a “tendril-ly” design, a complex web of geometric relationships must be built into the overall pattern of tendril features. When one or both ends of an existing tendril joins or splits from a tendril created earlier, “dependency” relationships are established between them, both “parent” and “child”.  In this new grill design there are about 25 such tendril features, all connected to each other in complex “parent-child” relationships. The tendrils by themselves are simple to create and edit, each consisting of just a starting outline, an ending outline, and a swoopy path connecting them.  However, editing such a pattern of dependencies that hold the design together is non-trivial.

This image here shows what a CAD model “Blow-up” looks like.  This happened while trying to edit a model, here the design of the new grill for the “First Edition” Ridgewing guitar, and something unexpected gets buggered. When first assembled together with the body frame, this new grill was found to mechanically interfere with it here and there along the mid-line.  To fix this, the inner grill edge line had to be moved out a bit from the frame’s outline, causing the entire grill pattern to be squeezed outward slightly. After doing this, when the whole grill was rebuilt, something obviously got buggered.