#Milestone3 — #IonicColumn

#VignolaBase and #AtticBase https://pixelfed.social/p/Splines/791248204071194527

Unadorned #IonicShaft https://pixelfed.social/p/Splines/791794072490907090

#Tectonic Classic #IonicCapital https://pixelfed.social/p/Splines/792124787573855518

Flat Classic #IonicVolute https://pixelfed.social/p/Splines/792724394068855690

#Milestone2 — Classic #IonicEntablature https://pixelfed.social/p/Splines/791021871062069787

#Milestone1 — #IonicPedestal https://pixelfed.social/p/Splines/790752092700055739

#IonicColumn #VignolaBase and #AtticBase #CAD Plans

Both #Vignola base and #Attic base have the same square footprint of 400 units x 400 units. The #plinth for both is 48 units (6 parts, or µ/3) tall, and the total height for both is 144 units (18 parts, or exactly µ). As such, they are easily interchangeable.

In the Vignola variant, we start at the plinth with a #fillet 2 units tall and a classic #scotia 18 units tall gouging out part of the fillet.

Then there is another fillet 2 units tall, followed by two #reeds, each 8 units tall, followed by another classic scotia as described above.

This is followed by yet another fillet 2 units tall and topped off with a #torus 40 units tall. A Torus is the same as a reed, except larger. When we reach the neck of the shaft, we will see another molding called #Astragal which has the same profile as reed and torus, but sits in the middle in size. Think of reed, astragal, and torus as small, medium, and large of the same profile.

The modern Attic variant is more elegant with fewer moldings. It also gives the impression of more heft for more stately columns. It starts at the plinth with a torus 36 units tall, followed by a fillet 4 units tall, followed by a modern scotia 24 units tall, followed by another fillet 4 units tall, and topped off with another torus 28 units tall.

As in the construction of #IonicEntablature [https://pixelfed.social/p/Splines/791013152244518907], split the construction of the #columnBase into two steps.

Just as we extruded #dentils separately, we extrude the plinth separately. First draw a square 400x400 in the top view. Then extrude the square 48 units in the front view.

For the rest of the base, we need a new 3D operation — #revolve around an axis. Instead of extruding the #primaryProfileCurve, we revolve it around the #columnAxis, and cap the #planarHoles on both ends before performing a #booleanUnion with the plinth. Finally check edges of the solid for #nakedEdges and #nonManifoldEdges.

#EvolutionOfScotia

#Scotia is a new concave #molding that we are seeing for the first time in the #IonicOrder. Its #primaryProfileCurve is a compound curve that is always segmented 1/3 and 2/3 from top to bottom. The two segments have different radii, but they also have a common tangent where they meet.

The scotia molding went through some evolutionary stages as shown in the sketch.

In the classic #Vignola version, the scotia used in the column base is smaller and gouges out a portion of the bottom fillet. Vignola did that to accentuate the effect of incident light and bring out the shadows. He must have really liked the #lightAndShade effect because he had TWO of them in the classic column base for the #IonicColumn.

An intermediary variant then emerged in which the larger arc was tangential to the bottom fillet instead of gouging it out. It still allowed for the interplay of light and shade as it had a lip that extended above the nominal fillet. Also, it was 4/3 the size of the Vignola variant and the fillets were twice as tall, ostensibly to make the lip more conspicuous, and provide some utility or justification for the lip.

If you are into #font design or you are an avid calligrapher, you will never look at font #serifs the same way after looking at the intermediate evolutionary stage of the scotia. In particular, the #Optima font is classified as #sansSerif, but the stem in its repertoire of characters has an uncanny resemblance at the tip of the lip.

Unfortunately, the lip didn't seem durable as it was prone to chipping. While Optima still thrives, designers rejected the lip of the scotia as vestigial over time, and used an ellipse for the larger arc so that it was tangential to the fillet right where the fillet ended. This design has endured, and the variant of the column base that uses this molding is called either the "modern" base or the #AtticBase. The etymology is from Latin #Atticus which means ‘relating to #Athens or #Attica region of #Greece.'