Carillon Redux: Continuing the Lantern

Completed column
The interior and exterior columns, and top and bottom scrolls are completed, and the candlestick is moved into place.

When we last left it, our model of the library lantern consisted of a single column section. The plan is to make 11 additional copies of this section and merge them to make a single mesh. We’ll create connecting sections that will become the sills and lintels of the windows between the columns.

First we’ll do a test to make sure that the columns will fit together as intended. Very quickly, we can make 11 copies using the center of the lantern as the origin. Each copy is offset from its neighbor by an angle of 30 degrees.

Preliminary lantern shape
The column assembly is duplicated to show the final lantern shape.

When this is compared to photos of the lantern, it’s apparent that some adjustments need to be made. For example, the base of the column needs to be narrower, and the capital needs to be wider. The extra copies are deleted and the mesh is corrected, then duplicated again to make two sections. Now we can bridge the gap between the sections with polygon meshes.

Bridging the gap
The space between two columns bridged with a polygon mesh.

There’s a problem, though. The edges of the bridging sections are perfectly straight, while in reality they follow a circular arc. Maya’s bridge tool is capable of creating curved shapes, but a few tests show that in this case it’s probably more trouble than it’s worth. The sills and lintels, with their overhangs, notches and ledges, are complex shapes. Each edge must follow a different arc, depending on its distance from the center of the lantern. We need another solution.

Circular curves are positioned along each horizontal edge of the model.

Here’s what I came up with: A set of centered, circular curves, each scaled and positioned to match one of the edges. Once those are in place, the edge vertices are repositioned horizontally to match the curves.

It sounds tedious, but the work goes very quickly.

Lantern shape
Once the bridges are complete, the lantern section is duplicated to create the entire shape.

Once the bridges are complete we can duplicate the section again to create the exterior shape of the lantern. This time, we can weld all the pieces into a single mesh.

Top Dome Profile Curve
The right side of the cupola is traced with Maya’s curve tool. (The curve is emphasized here to make it more visible.)

To make the cupola we use the same technique used to make the candlestick. After switching to the front orthogonal view, we trace one side of the cupola on the library drawing with Maya’s curve tool.

Top dome
The curve is revolved to create the cupola, which is then attached to the main lantern mesh.

The curve is revolved to make a polygon mesh that can be attached to the main body of the lantern.

With the cupola in place, we can make a new rendering to give us a better idea of how the lantern exterior looks at this point.

Lantern exterior
A quick rendering shows us how the lantern model looks at this point.