Enriching the Orders

Moldings can be left plain or carved with sculptural ornament of various kinds. In the same fashion, various areas of the Order can be provided with ornament, including the Necking of a Capital, and the Frieze and Soffit of the Entablature.

The subject of Classical sculptural decoration, both in terms of what types of ornaments are preferred over others, and how to reproduce it in SketchUp, could be a book of it’s own, so I am not going to go into any great detail here. As regards to what ornaments and enrichments to use, that is something that would differ based on what style you are working in and what Authority you are following, so will not be covered here, except for some brief statements by Chambers on the subject, that I believe are worth repeating.

As to how to construct sculptural forms in SketchUp, that is not something that has a simple answer. There are probably dozens of Extensions, in addition to the native tools, that could be used to replicate the different forms, and a lot of it would depend on exactly how much detail was wanted and how realistic or abstract an outcome was desired. In addition, the exact forms could vary, which would affect how they were constructed (for example, should an Acanthus Leaf be flat, or have some depth?, and should it be different if applied to a Corinthian Capital or a Frieze?).

As a result, in the following section I will show some brief, simplistic, methods to construct some of the most common sculptural enrichments used in regards to the Classical Orders, but for detailed construction, further study by the reader will be required.

Comments by Sir William Chambers on Ornament

In regards to moldings (such as an Ovolo or Cyma Reversa), Chambers advises any sculptural ornament be carved into the profile, and not added to the surface, so the actual shape and proportion is not changed. Further, he indicates that corners should be kept as close to the original profile as possible, which is why ‘water leaves, or other plain leaves’ are often used at corners, with the central ‘vein’ of the leaf forming the actual angle.

With regard to the Frieze, he indicates that any sculptural decoration should never project more than the uppermost molding of the Architrave under it. When talking explicitly about the Doric Frieze, he mentions the Metope ornamentation should not project more than the flanking Triglyphs.

In terms of the actual appearance, he favors a realistic representation, with the Eggs of the Ovolo or the Beads of the Astragal cut almost entirely detached, for example, while leaves or shells be kept flat, like the original objects they represent.

In the few examples shown below I will attempt to follow the above guidelines, so when evaluating and experimenting with the methods, keep in mind that the end result could vary greatly, based on the preferences of the style or Authority, as well as your personal taste.

The Bead Enrichment of the Astragal

The astragal molding can be enriched with carvings in the form of balls, discs, or ovals, frequently alternating with each other.

Chambers remarks The methods of the ancient sculptors, in the execution of their architectonic ornaments, was, to aim at a perfect representation of the object they chose to imitate, so that the … are in the antiques, cut round, and almost entirely detached, as are likewise the berries, or beads on the Astragal, which are generally as much hollowed out in the solid of the body, as the molding projects beyond it.

In his depiction of the Ionic order, Chambers shows the astragal adorned with two narrow discs centered under each egg of the ovolo over it, separated by a single elongated oval bead, with no string visible between the elements that I can see. Vignola, on the other hand, for his Doric Mutular order, shows the opposite, with a single elongated oval bead centered under the egg, and separated by a pair of discs, with the string connecting them clearly seen.

My example below will be created for Chambers’ Ionic order, and will be based on the design shown in his treatise.

As stated above, this design is enriched with a pair of discs below the center of each egg (or ‘ove’) in the ovolo of the capital, with an elongated curved bead stretching between them, so that means 24 pairs of discs located on the centerlines of each Wedge and 24 elongated beads in between them. As a result, I will work along the Red Axis, creating a Component that can be combined with the column shaft. If you are wanting to add this to an astragal in a capital (as Vignola depicts in his Mutular Doric order) you just need to adjust the following steps for the Capital Ovolo Wedge instead of the Shaft Wedge.

  1. Unhide the Column Shaft Profile
  2. Draw a Circle (of 72 sides) at the top of the Shaft Profile, centered on the Column Centerline, whose radius is the Midpoint of the Astragal (which is visible as a ‘break’ where the line of the top of the Shaft meets the half-circle curve of the Astragal), then Select the Edge, Right-Click, Explode Curve, then Double-click, and Make Group
  3. Open the Shaft Profile Component, and Select the half-circle Arc of the Astragal, Copy it, Close the Profile, Paste-in-Place, and Move it up on the Blue Axis from it’s bottom Endpoint to the Astragal’s top Endpoint, then Draw a Line connecting it’s Endpoints to make a Face, Double-click, Make Component (Astragal.Bead.Cap.profile)
  4. The component is aligned on the Red Axis, so Select it, and Rotate it so that it is aligned along the segment of the Circle to it’s left (or frontwards)

    Tip: You can do this by setting the start of the rotation to the right of the Column (away from the Circle) on the Red Axis, then using the actual Circle Side as the end of rotation.

  5. Draw a Line, coming up on the Blue Axis from the frontmost Endpoint of the Circle Side located directly under the rotated Arc, until it reaches the Midpoint of the Astragal (which should make it 1 2/3 min)
  6. Select both the Line and the Bead Cap, and Rotate them (using the Centerline as the point of rotation) from the Circle Division the Line is on counter-clockwise to the Circle Division directly on the Red Axis
  7. Draw a Line, starting at the horizontal Midpoint or Greatest Projection of the Astragal of the Column Shaft profile, coming up on the Blue Axis, for 3 1/3 min (which should be the same height as the top of the Line drawn above), then Select both Lines and Make Group
  8. Draw a Line, from the top of the vertical Line created on the Circle, going 2/3 min backwards on the Green Axis (towards the Bead Cap, but staying on the Green Axis), then Move that Line backwards on the Green Axis for 1/32 min (this creates the width of the disc, and a space between the pair of discs)
  9. Draw a Line, 1 2/3 min long, coming out on the Red Axis, from the Midpoint of the 2/3 min Line drawn above, then draw a pair of short lines going inwards on the Red Axis from the Endpoints of the 2/3 min Line, and Erase the (two halves of the) 2/3 min Line
  10. Draw an Arc, starting from the outer Endpoint of one of the short Lines drawn above, and ending at the outer Endpoint of the 1 2/3 min, making it tangent to the short Line, then do the same on the other side, then Erase the two short Lines, and draw a Line connecting the two Endpoints of the Arcs, Erase the Line running through the center of the Face that was created, Double-click, Make Component (Astragal.Disc.profile)
  11. Draw a short Line from the vertical Line on the Circle out to the closest corner of the Disc profile, then Select that and the Disc and Bead Cap profiles, and Move/Copy them backwards a distance until they are clear of existing Geometry, Right-Click, Flip Along Green Direction, then Move them back, using the Endpoint of the short Line to position them on the vertical Line on the Circle, then Erase the short horizontal Lines

    Note: Looking at this from Right View, this will give you an idea of the final Astragal. If you are not satisfied with the sizes or distances separating them, now is the time to make adjustments.

    You can get a clearer picture if you rotate the two Disc profiles (at the same time, using the top of the Line between them as the rotation point) for 90 degrees, then those for 180 degrees. Just be sure to Erase the rotated copies before continuing.

  12. Copy the Astragal Component profiles into memory, Hide the originals, Paste-in-Place, Right-Click, and Make Unique
  13. Rotate/Copy the Bead Cap copy (closest to the front) 85 degrees clockwise from it’s bottom Endpoint (so it ends on the circle division in the front located along the Green Axis of the Centerline), then Rotate that Cap again, using it’s bottom Endpoint as the rotation center, 2.5 degrees clockwise (this should make it now align along the Red Axis)
  14. Draw a short Line, going rightwards on the Red Axis from the Midpoint of the curve, then using the Endpoint of that Line as the Center, draw a Circle, with a 1 2/3 min radius, so the Circle’s Face is aligned along the Green Axis and the Blue Axis (i.e. at a right-angle to the Bead Cap), then Select the Edge of the Circle, and Cut/Copy it into memory
  15. Open the Bead Cap, Paste-in-Place, and use Follow-Me on the Face of the Component (to create a hemisphere), then Erase the Pasted Circle (Reverse Faces if necessary), Close the Component, Erase it and the short Line, then switch back to Right View to see the two Bead Caps in place
  16. Open the front Bead Cap, Double-click the flat Face, use Weld to join the Circle segments, Select the circle Edge, Copy it into memory, Close the Component, Paste-in-Place, and Rotate/Copy (using Centerline as point of rotation) for 5 degrees, then Select both Circles and Make Group
  17. Draw a Line, overwriting the circle segment between the two Circles in the Group, then Move it up on the Blue Axis for 1 2/3 min, then Cut/Copy it into memory, Open the Group just created, Paste-in-Place
  18. Select All, and run the Curviloft Extension ‘Create Loft Junction Following a Given Path’, then Erase the horizontal Line, Explode the Group Curviloft created, Close the Group, Cut/Copy it into memory, Open the front Bead Cap, Paste-in-Place, and Explode the Group

    Note: The Curviloft Extension has 3 functions, and this is not the one I have mentioned in the book before, so be careful to choose the correct function.

  19. Close the Component, Rename (Astragal.Bead.Cap.half), then Hide the Component
  20. Make one, and copy
  21. Draw a 1 2/3 min Circle, centered on the Endpoint of the vertical Line between the two Disc profile copies, aligned along the Blue & Green Axes, then Select it’s Edge, Cut/Copy it into memory, Open one of the Disc profile copies, Paste-in-Place, and Close the Component
  22. Move/Copy a Disc profile copy out a ways, then Scale it up 100 %, Open it, Select the Circle Edge, and run Follow-Me on the Component Face, then Erase the Pasted Circle, Close and Erase the Scaled Component

    Note: On my example, the arc edges were exploded, and the Faces were oriented the wrong way, so I fixed that Double-clicking one Face and running the Weld Extension, then Triple-Clicking and Reverse Faces.

  23. Rename the Disc profile copy (I just removed the ‘.profile’ from the end), then Hide the two Discs
  24. Erase the two Groups that still remain from the construction geometry, and Hide the Column Shaft Profile
  25. Unhide the Fluted Column Shaft Component, look at it in Top View, Open the Component, Select the Shaft Wedge Component to the right of the Centerline on the Red Axis, Copy it into memory, Close & Hide the Shaft Component, then Paste-in-Place, Right-Click, Make Unique, Rename (Column.Shaft.Fluted.Astragal.wedge)
  26. Open the Astragal Wedge, Select All, turn on Hidden Geometry (click ‘View’, then ‘Hidden Geometry’ on the Menubar), and then click ‘Edit’ on the Menubar, followed by ‘Unhide’, and ‘All’, then turn off Hidden Geometry, and Close the Component
  27. Unhide the four Astragal Components, and Move them down 3 1/3 min on the Blue Axis
  28. Open the Shaft Wedge, Copy the frontward side Face into memory, Close & Hide the wedge, Paste-in-Place, draw a Line from the bottom of the Congé on the Pasted Face inwards to the Centerline, then Erase everything below that, then use the Offset tool on the remaining Face, and extend it out so it completely clears the Astragal Components, then Erase the lines in the middle of the Face
  29. Double-click the new Face, Cut/Copy it into memory, Open the front Bead Cap, Paste-in-Place, Select All, Right-Click, Intersect Faces with Selection, then Erase the curved Face of the Bead Cap in front of the diagonal Face, then the diagonal Face, and the Edges remaining from the curved and diagonal Faces, then Double-click the flat Face and Hide it, then Close & Hide the Component, along with the other Astragal Components
  30. Unhide the Astragal Shaft Wedge, Open it, draw a Line from the upper inner corner where the Upper Cincture and Astragal meet, up to the top of the Wedge on the Blue Axis, on each side Face, then a Line across the top Face connecting the two previous lines, after which Erase the curved Face of the Astragal itself, and the two sides now projecting beyond the vertical Lines you drew
  31. The curved Cincture should have four joints where the individual segments meet, so draw a Line up on the Blue Axis from the top of each of these joints up to the top of the Wedge, then draw Lines from one outer corner of the Wedge to the Endpoints of the vertical Lines you drew and over to the other outer corner (forming Faces on the top and forming the outer curve)
  32. Copy the two new vertical Faces of the curve on the frontward side of the Wedge, Close & Hide the Wedge, Unhide the two Bead Caps, Open the front one, Paste-in-Place, Close the Component, Move/Copy it out a ways, and Scale it up 100% (Uniform Scale About Opposite Point)

    Note: I got a message from SketchUp saying “Your recent operation has caused visible geometry to merge with existing geometry that is hidden” when I Pasted-in-Place, but I clicked Ok. This will be cleaned up next.

  33. Open the Scaled Component, Select All, Right-Click, Intersect Faces with Selection, and Erase the back half of the Bead that is behind the Pasted Faces, then Erase the flat Faces behind the Bead, leaving the curve of the Bead and the flat Faces surrounding it, and Close & Hide the Component
  34. Unhide the two Astragal Discs, Open the front one, Paste-in-Place, Close the Component, Move/Copy it out a ways, and Scale it up 100% (Uniform Scale About Opposite Point)
  35. Open the Scaled Component, Select All, Right-Click, Intersect Faces with Selection, and Erase everything except the front portion of the Disc, then Close & Erase the Scaled Component, and Hide the two Discs
  36. Unhide the Astragal Wedge, and Erase the flat Faces forming the curve where the Astragal goes, and go ahead and cleanup any unhidden lines and edges that shouldn’t be there, including Hiding the top Edges forming the curve of the top of the Wedge, and the top Edges forming the top of the Cincture, then Close the Component
  37. Unhide the Bead Cap Components, Open the front one, and Hide any lines and edges that need it, especially any broken arc segments on the curve, and the lines separating the flat Faces of the back and forming it’s bottom, then Close the Component, and Unhide the two Disc Components
  38. Select the two Bead Cap & two Disc Components, Cut/Copy them into memory, Open the Astragal Wedge Component, Paste-in-Place, and Close the Component
  39. You can now Rotate/Copy the Wedge to create a full Shaft with Fluting & Bead decoration on the Astragal.

The Egg-and-Dart Enrichment of the Ovolo

The Enriched Ovolo of Vignola’s Mutular Capital

Vignola showed two different forms of Entablature for his Doric Order, one Mutular (upon which Chambers based the design explained above), and one Denticular (of which more information is found below). However, in addition to the differences in the Entablatures, they also featured differences in the Capitals.

The Capital he illustrated with his Denticular Order is the one Chambers (and most other Authorities) used, with an unadorned Ovolo above a set of three Annulets. The Capital illustrated with his Mutular Order, however, features an Ovolo enriched with Egg-and-Dart Molding, over an Astragal enriched with Bead-and-Reel Molding.

The decoration of the Ovolo with Egg-and-Dart or Fluted decoration was not common, but James Gibbs shows an Egg-and-Dart example in his Treatise (on Plate VIII), while Serlio shows a Fluted example among the alternative forms of the Doric Order in his Treatise (which he ascribes to a location in the Forum Boarium in Rome), and Hector d’Espouy shows a decorated Ovolo in his Plate on the Basilica Emilia in Rome.

Therefore if you want to add this ornamentation, you can follow the instructions under ‘An Egg-and-Dart Ovolo for a Cylindrical Capital’ in the Appendix. Just note that the instructions there are written for the Ionic Order, so the number of ‘Eggs’ would need to be adjusted to match the number of Flutes used in the Doric Column of your choice.

The Egg-and-Dart Enrichment

Almost all Ionic Capitals feature an Ovolo with some form of Egg-and-Dart enrichment (though not all, the Colosseum being perhaps the most famous example), and Chambers’ Ionic Order is decorated in this manner in his Treatise, so it will be followed here.

Note: This assumes the creation of the plain Ovolo Wedge Component, which will be used along with an Egg-and-Dart Template, to actually form the finished Component.

Chambers does not give any details for this, only saying “The ornaments of the capital are to correspond with the flutes of the shaft, and there must be an ove or a dart above the middle of each flute”. In his Plate devoted to Moldings & their Ornaments, he provides a total of 5 different designs for this enrichment, but does not give any further instructions.

In trying to come up with a way to model this in SketchUp I found quite a bit of information, but no exact set of instructions that I could translate easily to SketchUp.

The most complete textual and visual set of information I could find came from the works of James Gibbs (in Plate 28 of his ‘Rules for drawing the several parts of architecture’) and Batty Langley (in Plate VIII of his ‘The city and country builder's and workman's treasury of designs’), both of which use the same method, just treated in a slightly different way. The problem is that they only explain setting out the Elevation view of the Molding, not how it should be formed in 3d, around a Capital.

A second set of sources came from the 1999 Dover Edition of ‘Greek and Roman Architecture in Classic Drawings’, edited by Hector d’Espouy, where 5 different plates (4 - ‘The Propylaea on the Acropolis’; 7 - ‘The Temple of Athena Nike’; 67 - the ‘Forum of Trajan; 71 - the ‘Column of Trajan’; and 100 - the ‘Tomb of Alexander from Sidon’) showed the molding not only in frontal elevation view, but also in sectional and plan views. The plan views in particular are helpful in understanding how these moldings are constructed, as they are shown at multiple points along the height of the molding.

A final source I looked at were specific SketchUp tutorials found on the Internet. One Tutorial was in the form of a SketchUp Model by David Heim, found in the SketchUCation Forums (http://sketchucation.com/forums/viewtopic.php?f=183&t=56054). The other was a Tutorial called ‘Williamsburg Egg & Dart Carving in SketchUp’ by Timothy S. Killen, found on the Fine Woodworking site (http://www.finewoodworking.com/item/111242/williamsburg-egg-dart-carving). However, there were several issues I had with them, ranging from being modeled for a straight length of molding as opposed to a Capital, to the fact they both have a very wide top for the Egg, rather than the more curved head that Chambers shows, both of which made it hard to try and translate them into being used for a cylindrical Capital.

A more important problem (with all of the above) is that the proportions do not match those that I get from dividing the Ovolo into it’s 24 individual Wedges. The proportions of all the Egg-and-Dart examples are too wide to fit in the required space. Therefore the method I present below is adapted from the above sources, but modified to the proportions necessary to fit Chambers’ Ovolo.

The Egg-and-Dart Elevation of Gibbs & Langley

    The design shown by Gibbs and Langley is a frontal elevation only, and has proportions of 9 parts high to 14 parts wide. The following instructions will follow these proportions, which could be used as is, or as a template for forming the Egg-and-Dart enrichment for the Ovolo of Chambers’ Ionic Capital.

    Note: I present this to give an authoritative source that could be relied on, as well as a logical traditional method of construction, as this always makes it easier for me to then modify or translate into something more specific to SketchUp and 3D Modeling.

    This presumes either an empty Model, or one with all existing Components and Geometry Hidden, and that you are in Front View

    Set the Scales

  1. a. Draw a Line, starting at the Origin Point and going up on the Blue Axis, of the required height, and Divide the Line into 9 parts (this creates the Vertical Scale)

    Note: For the purpose of forming the Ovolo easier later on, the height is going to be set at 7 2/3 min, which is the height of the Ovolo of Chambers’ Ionic Capital, but you could make it whatever height you need.

  2. b. Select the top 7 parts just made and Rotate/Copy them 90 degrees counter-clockwise and clockwise, rotated at the top of the Scale (to create the Horizontal Scale)
  3. c. Select the 2 Scales and make them a Component (Ionic.Gibbs-Langley.Egg-and-Dart.Scale)
  4. d. Create a grid of Guides on each of the divisions above, by setting the 1st Guide, then using Move/Copy to set the next, and repeating by typing “x”, followed by “8” for the Guides going horizontally down the vertical line, and “6” for the Guides going vertically across the horizontal line (with one side done you can Move/Copy the Guides from one side to the other)

    Create The Egg Profile

  5. e. Draw a quarter-circle Arc (with sides set to 24 segments), clockwise, with it’s Center 3 parts down from the top on the Vertical Scale, with a Radius of 3 parts, it’s Startpoint at the intersection of the 2 Scales, going downwards towards the right (this forms half the top of the Egg)
  6. f. Draw another quarter-circle Arc (of 24 segments also), counter-clockwise, with it’s Center being 6 parts down from the top, also on the Vertical Scale, with a Radius of 2 parts, going upwards towards the right (this forms part of the bottom of the Egg)
  7. g. Draw a diagonal construction Line, starting 4 parts to the left of the Vertical Scale and 3 parts down from the top, going diagonally downwards and rightwards till it reaches the 6th part down from the top along the Vertical Scale (which is also the Center for the lower Arc drawn above), then continue that Line diagonally downwards just past the lower Arc, then Erase the portion of the lower Arc that extends above the Line, and the portion of the Line that extends below the Arc
  8. h. Draw a third Arc (also of 24 segments), using the starting point of the Line just drawn as Center, with the Radius being where the Line meets the lower Arc, and with the Endpoints being the smaller and larger Arcs

    Note: Here it is useful to Move/Copy the 3 Arcs that form half the Egg a short distance away from the rest of the Geometry, Deselect them, then Triple-Click one of the Arcs to make sure it Selects the other two, to verify connectivity between all three Arcs. If it does not check that you increased the number of sides for your Arc tool (I used 24 sides to achieve connectivity).

  9. i. Erase the diagonal line(s), and draw a Line from the bottom Endpoint of the lowest Arc up to the top Endpoint of the highest Arc, Double-Click the Face created, and make a Component (Ionic.Gibbs-Langley.Egg-and-Dart.Egg.profile)

    Create The Shell or Husk Profile1

  10. j. Draw a diagonal construction Line, starting 4 parts to the left of the Vertical Scale and 2 parts down from the top, going diagonally downwards and rightwards till it reaches the Midpoint of the 6th part down from the top, then continue that Line diagonally downwards till it is even with the bottom of the Scale Component
  11. k. Draw an Arc, whose Center is the intersection of the Vertical Scale and the diagonal Line just drawn, starting from the Midpoint of the lowest Part of the Vertical Scale and going counter-clockwise till it reaches the diagonal Line
  12. l. Now draw another Arc, whose Center is the Startpoint of the diagonal Line, going from the Endpoint of the Arc just drawn upwards till it is somewhat above the Horizontal Scale

    Note: The Startpoint of the diagonal line determines how close the upper portion of the Arc is to the Egg, so if you want to narrow the top you can set the Startpoint lower 1/2 or 1 Part, while keeping the 1st Arc Startpoint the same.

  13. m. Erase this diagonal Line, and draw another diagonal construction Line, starting 3 parts to the left of the Vertical Scale and 1 part down from the top, going diagonally downwards and rightwards till it reaches the Midpoint of the 5th part down from the top, then continue that Line diagonally downwards till it is even with the bottom of the Vertical Scale
  14. n. Draw an Arc, whose Center is the intersection of the Vertical Scale and the diagonal Line just drawn, starting from the bottom Endpoint of the lowest Part of the Vertical Scale and going counter-clockwise till it reaches the diagonal Line
  15. o. Again draw another Arc, whose Center is the Startpoint of the diagonal Line, going from the Endpoint of the Arc just drawn upwards till it is somewhat above the Horizontal Scale
  16. p. Erase the diagonal Line, and Draw a Line on the Vertical Scale along the Blue Axis, connecting the bottom Endpoints of the 2 curves, and another Line along the top of the Horizontal Scale, starting at the right Endpoint and going leftwards, intersecting the 2 curves (and creating a Face), then Erase the parts of the Arcs above the Horizontal Scale and the leftover segments of the Line on either side of the Arcs
  17. q. 19. Double-Click the Face just created and make a Component (Ionic.Gibbs-Langley.Egg-and-Dart.Shell.profile)

    The Dart Profile

  18. r. 20. Draw a Line going down from the far right of the Horizontal Scale down to the bottom of the Vertical along the Blue Axis, then continue the Line back up diagonally to 1 Part inwards from the first Startpoint on the Horizontal Scale, then finish by going right to the Startpoint of the 1st Line
  19. s. Note: The above is following the instructions from Gibbs & Langley, but they do not seem to mind or notice that the diagonal line just drawn intrudes into the outer curve of the Shell. An alternate location for the Endpoint of the diagonal line of the Dart would be the actual Endpoint of the outer curve. Since this is only a template, and is going to be adjusted for different types of Egg-and-Dart patterns, I am going to follow the original instructions here, and adjust the positions later.
  20. t. 21. Draw a Line, starting at the intersection of the diagonal Line drawn above and the Guide marking 2 parts up from the bottom, going upwards and leftwards to the very end of the Horizontal Scale on the left side (this will form the top angle of the Dart)
  21. u. 22. Draw another Line, starting from the bottom Endpoint of the vertical Line, and ending at the intersection of the Horizontal & Vertical Scales (this will form the bottom angle of the Dart)
  22. v. Note: Where you place these two diagonal lines will determine the projection of the side of the Dart into the area of the Shell. Placing it as indicated by Gibbs has the point of the side ‘barb’ intrude slightly into the area of the Shell. Langley’s drawing doesn’t make it clear where exactly the first diagonal line should start, but placing on the intersection of the 2nd part and either of the 2 other lines makes the intrusion even worse.
  23. w. The only way I can get the barb to not intrude into the curve of the Shell is to have the 2nd diagonal line go not to the intersection of the Horizontal & Vertical Scales, but 1/2 part over to the right of the Vertical Scale along the Horizontal Scale. I’m not sure why it doesn’t work when I do it the way Gibbs shows it, but it happens like this every time. For the purpose of this template I am going to follow Gibbs’ instructions, but be aware there is a way to draw this without another intrusion into the Shell.
  24. x. 23. Erase the diagonal construction lines, as well as the continuation of the diagonal Line down below the barb
  25. y. 24. Both Gibbs & Langley show another line going from the very bottom of the point of the Dart and continuing up to the Midpoint of the top of the Dart, so if you want to add that you can do so now
  26. z. 25. Triple-Click the geometry just created (so you can get both Faces if you drew the interior Line in the Dart) and make a Component (Ionic.Gibbs-Langley.Egg-and-Dart.Dart.profile)

    The Shell or Husk Back Plan

  27. aa. Note: This is not described in Langley’s text (though he describes everything else), so I am not 100% sure if this is the Plan of the Back, or a ‘Ceiling’ angling down from a flat front to meet the curved Back, or a perspective view (i.e. not a true ‘plan’). I include it here, but take into consideration my uncertainty of it’s purpose when re-using the Profiles.
  28. ab. 26. Draw a temporary Line, coming out a little on the left of the Vertical Scale 2 parts down from the top, then draw an Arc, whose Startpoint is the right Endpoint of the Line just drawn and whose Endpoint is the top Endpoint of the inner Arc of the Shell, making this Arc tangent to the temporary Line
  29. ac. 27. Then draw a Line from the Endpoint of the Arc just drawn, inward along the Horizontal Scale to the Vertical Scale, then down to the Startpoint of the Arc, Double-Click the Face just created and make a Component (Ionic.Gibbs-Langley.Egg-and-Dart.Shell.plan), then Erase the short temporary Line

    Finish

  30. ad. 28. You can now Select all of the Components created above (except for the Scale) and make them a Component (Ionic.Gibbs-Langley.Egg-and-Dart.profiles)
  31. ae. Note: Here I would save this Component to disk, so that it could be used elsewhere, since as a template it could be customized to fit in other locations.
  32. af. Also, I would change the Axes so they are at the top left of the Component (the top centerline of the Egg) as I think that would be the most likely place to insert them.
  33. ag. With the above complete, the Profiles Component can be used as a template to create the Chambers’ specific version to apply to the Ovolo of his Ionic Capital

    An Egg-and-Dart Ovolo for a Cylindrical Capital

    Since Chambers does not provide any instructions for this, I will adapt the design of James Gibbs & Batty Langley.

    As stated above, Chambers does not provide any information on creating this enrichment, and

    the design by Gibbs & Langley is proportioned differently than the Ovolo of the Capital (as indeed are several other sources I looked at). In addition, I tried importing an extract of a scan of Chambers Ionic Order showing just the central Egg-and-Dart of his Ovolo and it appears to be wider than the Ovolo I created as well. I even double checked the dimensions (which at 7 2/3 min high are correct), and the number of Flutes/Wedges (which Chambers clearly shows as 24), to see if I had erred in forming the Component.

    Therefore the steps below are only a rough guide on how to form this enrichment, and the actual shapes are left to the Reader to alter to their liking. I apologize that I can’t offer a more authoritative source for the following, but this is the best that I have been able to come up with.

    The form of Egg-and-Dart that I will show below is based on Chambers’ Plate on the Ionic Order, which shows an Egg with a Shell surrounding it on the sides and bottom, the Shell connecting with the ones on either side via a spur at the top, and with arrow-headed Darts between the Shells coming down from under this spur.

    Note: The following assumes the Ovolo Component is already created and is formed of individual Wedge Components created in the same manner as the Ionic Column Shaft mentioned earlier in the Appendix, with 24 Wedges/Flutes. For a Column with a different number of Wedges/Flutes, adjustments might have to be made.

    Alternatively, you can have just the initial Wedge component created, and skip the first two steps below, simply making a unique copy of it to use.

    In addition, it assumes the existence of the Ionic Gibbs-Langley Egg-and-Dart Component created above, to serve as a guide.

    Initial Setup & Scaling

  1. 1. In Top View, with only the Capital Ovolo Component visible, Open the Component, Select the Wedge Component to the right of the Centerline on the Red Axis, Copy it into memory, Close & Hide the Ovolo Component, then Paste-in-Place, Right-Click and Make Unique

    Tip: If you click just to the right of the center of the round top you should find the correct wedge. The selection box should look like it’s top-left corner is on the center and is even with the midpoint of the right side of the angled selection box.

  2. 2. Open the Wedge copy, turn on Hidden Geometry (click ‘View’, then ‘Hidden Geometry’ on the Menubar), and then click ‘Edit’ on the Menubar, followed by ‘Select All’, then ‘Edit’ again, followed by ‘Unhide’, and ‘All’, then turn off Hidden Geometry, and Close the Component, and Switch to Right View
  3. 3. Insert the Gibbs-Langley Egg-and-Dart Profiles Component so it’s left Edge is positioned on the greatest projection of the Wedge top surface, and angled to the right side of the Wedge centerline along the Green Axis

    Note: The elements of this Component will be used as a rough guide for the various pieces, but will not be followed exactly. My goal was to get a final result looking close to that Chambers’ shows in his Plate on the Ionic Order, so some artistic license is used here to modify the design as I feel necessary. As this is a very subjective measure, use your own judgment in the following steps.

  4. 4. Copy the Component, Hide the original, Paste-in-Place & Explode, then Select the individual Components, Make Unique, and Rename (all I do is replace the ‘Gibbs-Langley’ with ‘Chambers’ and remove the ‘#1’ that SketchUp added; i.e. Ionic.Gibbs-Langley.Egg-and-Dart.Shell.profile#1 to Ionic.Chambers.Egg-and-Dart.Shell.profile)

    Note: Alternatively, you could just Explode the original Component, but the Arcs forming the individual Components need to be adjusted for the following operations to work due to the complex geometry involved, so I feel it is a good idea to keep the original in case it needs to be re-used.

  5. 5. In order to minimize errors later on, the Geometry needs to be simplified, so Open the Egg Profile, and select each Arc and change (or verify) the number of segments forming it so the top two are formed of 12 segments, and the lower is formed of 6 segments, then Close the Component, and repeat for the Shell Profile (making it’s top curves 12 segments and the bottom curves 6 segments) and the Plan Component (making it’s curve 12 segments)

    Tip: The method I use to change the number of Segments per Arc is to Select the Arc, then look at the Entity Info Dialog Box, and where it says ‘Segments’, type in the new number I want and then use the Tab Key to exit out of the Text Field and ‘Set’ the number.

  6. 6. The proportions now need to be adjusted, so draw a temporary Line coming out on the Red Axis from the top right corner of the Wedge till it is even with the 3 Components, then continue down on the Blue Axis till it is past those Components
  7. 7. Select the Dart, and Shell Plan & Profile Components, and use the Scale tool on the middle side grips (going from right to left, which Scale reports as ‘Green Scale about Opposite Point’) to change the width so the right edge is aligned with the temporary Line created above (Scale should report it being ‘On Edge’), then Erase the temporary Lines

    Note: At this point you can see a rough outline of how the elements work together. I feel the Egg looks right, but the Shell is too close to the Egg, and the Dart is too large, so those elements will be adjusted. In addition, the Shell is missing the spur that connects one Shell to another over the Darts, so that will be added in as well.

  8. 8. Open the Shell Profile Component, and draw a Line going up on the Blue Axis off the top left corner of the Shell a short ways (to act as a Handle), then Select it, and Move the bottom Endpoint rightwards (on the larger model’s Green Axis, though the Component will refer to it as it’s Red Axis) till it is even with the joint between the two segments of the Arc on the top of the Ovolo, and then Erase the Handle
  9. 9. The lower part of the Shell needs Moving now, so draw another short Line coming out from the joint where the two Arcs of the inner curve meet, Select the Handle, and using the Endpoint at the joining of the two Arcs Move the Handle 3/16 min to the right (where SketchUp will report ‘On Red Axis outside Active’), then repeat for the outer curve, and Erase both Handles
  10. 10. To add the Spur sitting over the Dart, set a Guide, coming down from the top Edge of the Shell, equal to the lowest point of the Egg-and-Dart Plan, and draw a Line from the intersection of the Guide and the outer curve, going outwards to the right on the Green Axis till it is even with the top right corner of the Wedge, then continue it upwards on the Blue Axis to the top of the Shell, then leftwards till it meets the Shell outer curve again, then Erase the Guide and the Line separating the new part from the old, and Close the Component

    Note: The Dart will have to be altered as well, but this will be done later, when you can judge exactly how much it needs to be adjusted.

    Creating the Front Face of the Shell

  11. 11. Hide the Egg, Plan & Dart Profiles, Copy the Shell Profile Component, Hide the original, Paste-in-Place, Make Unique, and Rename (Ionic.Chambers.Egg-and-Dart.Shell.half)
  12. 12. Open the Ovolo Wedge Component, Select the outer curved Face, Copy it into memory, Close & Hide the Wedge, Open the Shell Half Component, and Paste-in-Place
  13. 13. Now use the Weld Extension to join the separate Arcs forming each of the inner and outer curves of the Shell into a single Arc, then Close the Component
  14. 14. To better ensure the following step works, Move/Copy the Component out a bit, and Scale it up (using diagonally opposite grips for ‘Uniform Scale about Opposite Point’) by 100 %, then Zoom Extents to see the enlarged Component
  15. 15. Open the Copy, use the Push/Pull tool to extrude the Shell Face backwards to the bottom middle point of the curved Face, then Select All, Right-Click, and Intersect Faces with Selection
  16. 16. Cleanup the unwanted parts by removing the flat Face of the Shell Profile, the curved Faces of the Wedge flanking it, the flat top Face, the curved and flat Faces of the Shell facing Front View, the back Face, then all the other Geometry except the new curved Faces of the Shell facing Right and Rear Views
  17. Tip: At this point it is useful to use the Weld Extension, this time specifically to join the segments of the inner & outer arcs forming the sides of the curved Face of the Shell. One method you might use, due to the curved surfaces, is to Double-Click the curved front of the Shell, apply the Weld Extension, then draw short Lines coming off the ‘corners’ where the Geometry would normally ‘break’, then Erase the short Lines.
  18. 17. When done, Close the Component, Erase it, and Zoom Extents again to see the original Component

    Creating the Inside of the Shell

  19. 18. Unhide the Ovolo Wedge Copy and Shell Plan Components, then Rotate the Shell Plan 90 degrees backwards so the curve is closer to the Column Centerline and it is shown on top of the Wedge, then Move it backwards along the Red Axis till it’s front right point is aligned with the top left front corner of the Shell (you don’t want to move it sidewise so it touches, that will be done next)
  20. 19. Select the Plan Component, and Scale it lengthwise on the middle grips (Red Scale about Opposite Point) till it’s front right Endpoint meets the left top Endpoint of the Shell Component

    Tip: Another method would be to Open the rotated Plan, draw a Line going out from the right triangular corner a short way to act as a Handle, Select the Line, and use the Endpoint connecting to the Plan to Move it rightwards till it meets the corner of the Shell Component, then Erase the Handle

  21. 20. Hide the Ovolo Wedge, Unhide the Egg Profile Component, switch to Front View, and create a Rectangle, whose top right corner is the top Endpoint of the centerline Edge of the Egg Profile and whose bottom left corner is the top front corner of the inner curve of the Shell, and make it a Group
  22. 21. Draw a short Line going down on the Blue Axis from the bottom left corner of the Group just made, and then draw an Arc, starting from the top of the Line just drawn, and ending at the front rear corner of the Plan Component, making the Arc tangent to the short Line, then Erase the short Line, and Hide the Group
  23. 22. Open the Shell Component and Select the Edge Arc forming the inner curve, Copy it into memory, Close & Hide the Component, Paste-in-Place, then Select the Arc created on the Face of the Rectangle and the Arc you just Pasted, Cut/Copy them into memory, Open the Plan Component and Paste-in-Place, then Erase the 2 straight Edges of the Plan
  24. 23. Select all 3 Arcs in the Plan Component, and use the Curviloft Extension ‘Skinning of Shapes, Loft junctions following two paths’, then Cut/Copy the Group Curviloft created, Close & Hide the Plan Component, Paste-in-Place, Right-Click the Group and make it a Component

    Note: This will be a temporary Component so you don’t need to rename it.

  25. 24. Copy the Egg Profile Component, Hide the Original, Open the Group Component, Paste-in-Place, and Explode the Egg Profile Component, then Close the Component
  26. 25. Just as before, to better ensure the following step works, Move/Copy the Component out a bit, and Scale it up (using diagonally opposite grips for ‘Uniform Scale about Opposite Point’) by 100 %, and Zoom Extents to see the enlarged Component
  27. 26. Open the Scaled Copy, use Push/Pull to extrude the Egg Face backwards till it goes through the Shell Back, then Select All, Right-Click, and Intersect Faces with Selection
  28. 27. Now Double-Click the two Egg Faces & Erase them, along with the two curved Faces of the Back, along with the Edge corresponding to the Egg centerline, so you end up with only the four curves making up the frame for the Shell Back
  29. 28. Now, Select all of the inner curve (that represents the Egg Profile) and use Weld to join the segments into a single Arc, then Save your work

    Note: Here you may run into a couple of problems, which, no matter how I try, I can’t seem to totally prevent.

    If you cannot select the entire curve and make it a single Arc, then you will have to Zoom in close to the inner curve and find where the individual Segments of the Arc are missing, and add the necessary Line Segments.

    If you can Select the entire curve and Weld it into one Arc, Save your work and see if SketchUp reports any errors, and if so let SketchUp fix them, then go back and double check the Geometry and see if SketchUp inadvertently introduced any errors in the inner curve that now need correcting.

    It might be easier for you to go along the entire length of the inner curve and replace sections that have multiple small Segments with larger single Lines. Just be sure to use Lines and not Arcs, so the connections will be correct in all three directions.

    Due to the way this inner Arc curves both horizontally and vertically as well as diagonally, the Geometry can be tricky to get just right. It is for this reason that I am not keeping the Face that would stretch between these Arcs and will recreate it below, as trying to use the original Face has proven almost impossible without major cleanup of the Geometry associated with the inner curve.

  30. 29. When you can successfully turn the inner curve into a single Arc, use the Curviloft Extension ‘Skinning of Shapes, Loft junctions following two paths’ (this creates the Back Geometry for the Shell), then Close and Erase the large Copy, and Zoom Extents to see the original Group Component

    Note: If the Curviloft Extension doesn’t work, the chances are the inner curve is not completely connected, so go back over the Geometry again.

  31. 30. Unhide the Shell Half Component, Open the Group Component and Copy the Group Curviloft created into memory, then Close & Hide that Component, Open the Shell Half, and Paste-in-Place, then Explode the Group, and Close & Hide the Component

    Creating the Egg

  32. 31. Another profile needs to be created for the Egg, so Unhide the Rectangle Group, the Ovolo Profile, and the Egg-and-Dart Plan & Egg Profile Components
  33. 32. Set a Guide on the Face of the Rectangle at the height where the two upper arcs of the Egg Profile join, then draw a short Line, heading downwards and leftwards following the curve of the Ovolo Profile where it meets this Guide (this will help to form a point of Tangency for the next step)

    Note: The placement of this is somewhat arbitrary on my part. If you place the point of tangency higher on the curve of the Ovolo that alters the proportions of the Egg, so you might want to experiment with different locations to see what produces a shape you are most comfortable with. As stated at the beginning, there is no instructions for doing this that I could find, so it is a matter of personal taste.

  34. 33. Draw an Arc, using the upper Endpoint of the Line just drawn as the Startpoint, and the top rear front corner of the Plan as the Endpoint, so that it is tangent to the short Line drawn above (this will serve as the outer front curve of the Egg), then Erase the short tangent Line
  35. 34. Set a Pair of Guides on the Face of the Rectangle, at the heights where the two lower arcs of the Egg Profile join and at the bottom of the Egg Profile, then draw a short Line, heading upwards and rightwards following the curve of the Ovolo Profile where it meets the first Guide just created (this will help to form a point of Tangency for the next step)
  36. 35. Draw an Arc, using the lower Endpoint of the Line just drawn as the Startpoint, and the intersection of the second Guide created in the previous step and the Arc from the Plan component linking the Plan and the bottom of the Shell Component as the Endpoint, such that it is Tangent to the short line, then Erase the short Line as well as the Guides
  37. 36. Now Erase the Rectangle Group and Hide the Egg Profile & Plan Components, then Copy the Ovolo Profile, Hide the original, Paste-in-Place, Right-Click, Make Unique and Rename (Ionic.Chambers.Egg-and-Dart.Egg.construction)
  38. 37. Cut/Copy the 2 Arcs, Open the Egg Construction, Paste-in-Place, then Erase all but the 2 pasted Arcs and the Arc from the Ovolo joining them together, then Close the Component
  39. 38. Unhide & Open the Group Component, Erase the Group Curviloft created (which is no longer needed), Copy the inner curve Arc into memory, then Close & Erase the Component
  40. 39. Open the Egg Construction Component, Paste-in-Place, and Close the Component
  41. 40. Draw a Rectangle, whose right front corner is the junction of the two upper Arcs of the Ovolo Profile, so that it extends backwards past the Arc from the Shell Back, then Double-Click this Face and make it a Group
  42. 41. Now draw a short Line coming out from the right front corner of the Group just created heading frontwards along the Green Axis, and use the beginning of this Line as the Startpoint for an Arc that terminates where the flat Plane intersects the Arc of the Shell Back (this will form the curvature of the Egg)
  43. 42. Erase the short Line and the Plane Group, Cut/Copy the Arc just created, Open the Egg Construction Component, Paste-in-Place, Select All, and then use the Curviloft Extension ‘Skinning of Shapes, Loft junctions following two paths’
  44. 43. Cut/Copy the Group Curviloft created, Close & Hide the Component, Paste-in-Place, Right-Click, Make Component, and Rename (Ionic.Chambers.Egg-and-Dart.Egg.half), then Hide

    Creating the Dart

  45. 44. With the Shell Half, Dart Profile & Ovolo Wedge Copy Components visible, Move the Dart back towards the Centerline on the Red Axis till it’s upper right rear corner meets the upper right outer corner of the Ovolo Wedge just behind it, then Rotate the Dart till it is aligned with the angle of that first segment of the curve of the Ovolo front

    Note: In my case, using the dimensions above, it comes out as 7.5 degrees.

  46. 45. The Dart needs to be re-sized so it doesn’t intrude into the Shell, so Hide the Wedge, Open the Dart Profile and use Push/Pull to extrude the Face backwards till the upper left point of the Dart intrudes into the Shell to gauge how much you need to Move the Dart point, then Undo the Push/Pull Operation

    Note: There is going to be a curved Face separating the Shell and Dart just a little behind the Shell, so it is acceptable for the Dart to intrude into the Shell just so long as after this backing is created that the Dart is still free of the Shell.

    In my case I moved the point down and to the right about 1/2 minute in both directions.

  47. 46. Draw a short Line as a Handle coming off the left triangular top of the Dart itself, then Select the Line, and, using the Endpoint attached to the Dart, Move it out and down the distance you determined was best from the above operation, then Erase the Line and Close the Component

    Note: You might want to Move the point & extrude so you can determine the form of the Dart that you are comfortable with before you completely finish the operation.

  48. 47. With the Dart re-sized, Copy the Dart Component, Hide the original, Paste-in-Place, Make Unique, and Rename (Ionic.Chambers.Egg-and-Dart.Dart.half)
  49. 48. Hide the Shell Component, Unhide the Wedge, then Switch to Rear View, and, using the existing top and bottom of the Ovolo Arc as your Startpoint and Endpoint, draw an Arc that is slightly shallower (this will form the Face of the Dart, which in Chambers version of the Egg-and-Dart sits back of the Shell a little)

    Note: In my case, having the Ovolo created using Equilateral Triangles, I made the ‘bulge’ be 1 1/4 minutes.

  50. 49. Open the Wedge Component, Double-Click the back Face, Copy it into memory, Close & Hide the Component, Paste-in-Place, draw a Line from the bottom Endpoint of your Arc straight up to the top of the Ovolo on the Blue Axis, then Erase the Geometry to the right of the Line just drawn (looking at it from Rear View), along with the Geometry to the left of the Arc just drawn
  51. 50. Double-Click the Face, Cut/Copy it into memory, Open the Dart Half, Paste-in-Place, then Close the Component
  52. 51. Like before, Move/Copy the Component out a bit, and Scale it up (using diagonally opposite grips for ‘Uniform Scale about Opposite Point’) by 100 %, and Zoom Extents to see the enlarged Component
  53. 52. Open the Scaled Component, and Push/Pull the side of the Ovolo outwards to the left till it is past the point of the Dart, then Push/Pull the Dart itself backwards to the rear Edge of the side of the Ovolo

    Note: Technically I suppose this should be curved to follow the face of the Ovolo, but in reality only a small part of the tip of the Dart would be at a different angle, so I don’t think it is worth the extra effort. If you want to have it curved, you can modify the steps for creating the Wedge below to adapt these steps.

  54. 53. Now Select All, Right-Click, choose Intersect Faces With Selection, then remove all the geometry except for the curved Dart itself along with the Geometry right behind it, then Close & Erase the larger Component, and Zoom Extents to see the original Component

    Note: Do not Double-Click the Dart Face when cleaning up the extra Geometry, as that will remove part of the curved Face of the final Dart.

    Creating the Egg-and-Dart Half-Wedge

  55. 54. Once again Unhide & Open the Wedge Component, Double-Click the back Face, Copy it into memory, Close & Hide the Component, Paste-in-Place, and, using the existing top and bottom of the Ovolo Arc as your Startpoint and Endpoint, draw an Arc that is slightly shallower than the Dart, whose Edge you should see through the Ovolo Face

    Note: In my case, using the dimensions noted earlier, I made the ‘bulge’ be 1 minute.

  56. 55. Now Hide the Dart, and Erase the part of the Ovolo Face to the left of the Arc just made, so you end up with a new, shallower, Ovolo Profile, which you Double-Click and make a Component (Ionic.Chambers.Egg-and-Dart.Core.profile)
  57. 56. Using the same method as used to create the original Ovolo Wedge, create another Wedge using a copy of the Profile above, naming it Ionic.Chambers.Egg-and-Dart.Core.wedge.half

    Note: If you need a refresher, this can be found under ‘Turn a Profile into a Pie-Shaped Wedge and Cylinder’ in the Appendix.

  58. 57. Once the Wedge is made, draw a Rectangle through it’s centerline, with the top right corner at the center joint of it’s curve on top, and the bottom left corner at the apex of it’s bottom on the Centerline, then Double-Click the Face, Cut/Copy into memory, Open the Wedge.half, Paste-in-Place, Select All, Intersect Faces with Selection, and Erase the half frontwards of the centerline of the Wedge, including the portion of the Rectangle projecting out of the curve of the Ovolo

    Note: I create this as a half-wedge as the other elements of the Egg-and-Dart are being created as half elements, and this will facilitate working with those, as well as limiting Geometry.

  59. 58. With the Core Wedge Half visible, Unhide the Shell Half Component, Copy it, Hide the original, Paste-in-Place, and Make Unique
  60. 59. Open the Wedge Half, Copy the outer curved Face & rear flat Face into memory, Close & Hide it, Open the Shell Half Copy & Paste-in-Place
  61. 60. Set a Guide, coming down from the top of the rear Wedge Face, at the height of the bottom of the Spur of the Shell, then draw a Line, starting from the bottom rear corner of that Spur, backwards along the Guide till it reaches the rear Face, Erase the remainder of the rear Face between the outer curve and the Centerline, then Close the Component
  62. 61. Like before, Move/Copy the Component out a bit, and Scale it up (using diagonally opposite grips for ‘Uniform Scale about Opposite Point’) by 100 %, and Zoom Extents to see the enlarged Component
  63. 62. Open the Scaled Component, Select All, Right-Click, and choose Intersect Faces with Selection
  64. 63. Draw a Line from the intersection of the side of the Spur and the curved Face frontwards to the inner corner to create the bottom of the Spur
  65. 64. Now Erase everything but the area under the Spur, leaving that curved front, the rear side of the Shell, and the bottom of the Spur
  66. 65. Close & Erase the larger Component, and Zoom Extents to see the original Component
  67. 66. Unhide the Dart Half, Copy it into memory, Close & Hide it, Open the Shell Half copy, Paste-in-Place, Explode it, then Close the Component
  68. 67. Once again, Move/Copy the Component out a bit, and Scale it up (using diagonally opposite grips for ‘Uniform Scale about Opposite Point’) by 100 %, and Zoom Extents to see the enlarged Component
  69. 68. Open the Scaled Component, Select All, Right-Click, and choose Intersect Faces with Selection
  70. 69. Now Erase the rear Face(s) of the Geometry, along with the Face above the Spur, so that all is left is the bottom of the Spur, the Dart under the Spur, the rear side of the Shell, and the curved Face between the Shell & Dart
  71. 70. When finished, Close & Erase the larger Component, and Zoom Extents to see the original Component
  72. 71. Unhide the Shell Plan, Open it and Copy the top Arc into memory, then Close & Hide it, and Paste-in-Place
  73. 72. Now Select the Arc just Pasted and the Shell Half Copy, Cut/Copy them into memory, Unhide & Open the Core Wedge Half, Paste-in-Place, and Explode the Shell Half Copy
  74. 73. Erase the curved Face of the Wedge Half, along with the front corner of it’s top away from the Centerline (where the curve of the Plan divides it from the rest), along with the front and rear side Faces of the Wedge Half as well as any now unnecessary Lines, then Close & Hide the Component
  75. 74. Unhide & Open the Shell Half Component, and Erase the rear curved Face with it’s associated Line & Arc, then Close it
  76. 75. Now Unhide the Core Wedge Half & Egg Half Components, Copy the Egg & Shell Half Components into memory, Hide them, Open the Wedge Half Component, Paste-in-Place, Explode, and Hide the Edges of the Wedge that are located on either side, then Close the Component

    Assembling the Egg-and-Dart Ovolo

  77. 76. Move/Copy it frontwards a short distance on the Green Axis till it clears the original, then Right-Click, Flip Along Component’s Green, and Move it backwards on the Green Axis till it joins with the original Component
  78. 77. Select both Components and create a new Component (Ionic.Chambers.Egg-and-Dart.wedge)

Adding Sculptural Ornament

With regards to adding sculptural ornament, I will give two examples, one for adding ‘bucrania’ to the Metopes of the Doric Frieze, and the other to adding a Floral Ornament to the Corinthian Soffit.

The Bas-Relief Ornament of the Doric Soffit

As stated earlier, Chambers shows flowers & foliage in his panels, along with winged thunderbolts in the corners. The creation of this bas-relief sculpture is beyond the scope of this book, except in the most rudimentary way. For a brief introduction to adding these sculptural elements to the soffit, see ‘Adding Sculptural Ornament’ in the Chapter ‘Enriching the Orders’.

Note: One thing to keep in mind, is that Chambers advises the ornaments never drop down below the plane of the soffit. The moldings created above are recessed 1 1/2 min into the soffit at their deepest. If you wanted them deeper, you could change the 1/4 min depths to 1/2 min depths (thus adding another 1/2 min total), which would still be within Chambers’ 2 min limit for recessing elements into the soffit.

The Bas-Relief Ornament of the Metopes in the Doric Frieze

DON'T KNOW WHAT THIS IS; NEED TO FIX. y have bas-reliefs of some sort that repeat down the length of the entablature, though frequently having designs that alternate to provide some variety.

These ornaments can be virtually anything, and Chambers goes into some detail about what he thinks is and isn’t proper to place there. A few things he stresses are that there should not be too many different designs (advocating only two different designs) and that they should be symmetrical about the composition, so they are the same on either side of the center of the building or room. He also stresses that the bas-relief ornamentation should not project out farther than the triglyphs flanking them.

The Doric Bucranium

The ‘bucranium’ is the skull of an ox or cow, and is frequently found in Roman & later Friezes, especially in the Metopes of the Doric Entablature.

For this example, I used the Plate from Chambers’ Treatise, where he shows one of these symbols in the Metope of his Doric Mutulary Order.

  1. First I scanned the image (from Dover Publications wonderful reprint of Chambers’ Treatise) at 300 dpi greyscale, then opened it in The GIMP (an open-source raster editing program) and cropped out just the square Metope containing the bucranium, and saved that as it’s own file.
  2. I opened up SketchUp, and created a new File (Chambers.Bucranium) for the project
  3. Then I created a square 45 min wide by 45 min tall, with it’s bottom Midpoint on the Origin point, and the Plane standing vertical on the Blue Axis

    4. Note: The above dimensions are the size of the intended destination, the Metope, between the Triglyphs of the Doric Order.

  4. Next I imported the cropped image into SketchUp (via ‘File’, ‘Import’), and placed the image onto the Plane I created above, then Selected All and made it into a Component (Metope.Image)
  5. Next I turned on X-Ray View, drew a Line from the top Midpoint down to the bottom Midpoint of the Component, and started to ‘trace’ over the image using different SketchUp tools

    6. Note: Turning on X-Ray View was necessary to see Geometry being created on top of the Component.

  6. The actual process of tracing can’t be gone into too much, as it will differ so much based on your source image, but I started by creating a Centerline, then setting Guides at different locations comparable to parts of the image (such as the tips of the horns, or tops of the eye sockets), and then mainly used the default Bezier Extension, along with the Line & Arc tools, to provide an outline of the major elements of the image I wanted to replicate in three dimensions, each of which was created it’s own Component to ease with construction

Note: The actual image from Chambers was not symmetrical, but I did not need to go into that level of detail as to create unique halves, so I only traced over the right side, which I could then mirror to form the entire skull.

One general method that could be used would be to import an image of whatever decoration you wanted to add, use SketchUp’s native tools (like the Line, Arc, Circle, or Bezier tool) to outline the forms to get Faces, then use Push/Pull to raise or lower different sections to get a rough outline approximation of the form, then Hide the Edges, so the raised areas have a more softer look.

Note: For more realistic representations I would advise looking at the numerous tutorials on sculptural work using SketchUp that can be found either in books or online in Internet sites.

To create this type of bas-relief ornaments, I Import appropriate images into SketchUp, trace over them to get the level of detail I want, then used Push/Pull tool to add some depth to the different Faces. How much you want to work on them would be determined by how much they would be visible, what forms you are using, and how much additional Geometry you want to add to your Model.

Search for “sculpting with sketchup” for example.

The Hanging Pinecone of the Dentil Entablature

This is alternately referred to as a Pinecone, an Acorn, or even a Pineapple (according to Robert Chitham).

The Dentil Pinecone

The Dentils run along the Entablature, in front of the Dentil Fascia, but at the corners they end at the edge of the Fascia, leaving a blank spot on the corner. This is frequently filled with an ornament in the form of a hanging pinecone.

As was stated in the Chapter on the Doric Order, detailed sculptural decoration is beyond the scope of this book. However, a simple set of instructions can be found in the section The Hanging Pinecone of the Dentil Entablature in the chapter Enriching the Orders.

The Rosette of the Eye of the Ionic Volute

Note: Chambers shows an ornament of some kind on the face of the eye. Serlio refers to this as a ‘rosette’, so you can add any type of round ornament in bas-relief here if you wish (though I would wait until the rest of the capital is finished first).

The Honeysuckle Sprig Ornament of the Ionic Capital

Plate 74 in Architectural Drawing by Wooster Bard Fields Composite