Make it Flat or not. If it's arched, you can set either the Spring Height or the Arch Height, and the other dimension will change to maintain the overall height.
If Flat is on, the arch/lintel can be Segmented (separate arch stones) or Solid (a one-piece lintel). With Flat off, the curved arch must be segmented and the Style parameter is hidden.
A Flat arch/lintel has options for the Bearing dimension and Angle at both ends. Example of angle usgae: A brick jack arch.
A segmented arch, Flat or not, will be made of stones measuring, at most, the Stone Max Width. You can have a Keystone, which can have its own Width. To omit the keystone, set the Keystone Height to 0.
The big new feature in this version is the Squiggly Stone option. This will give a (little) more natural shape to the lintel or arch stones. The squiggly parameters and behavior are different depending on whether the arch/lintel is 'Segmented' or 'Solid'.
In the current version, a segmented arch will only be drawn squiggly at scales less than 1/4" (1/2" scale and larger). This is to conserve resources in 3D/section/elevation, because the squiggly arch uses a lot more polygons. If you want to override the scale control, turn on the Force Nicer Arch parameter. I'm thinking about a way to do low-scale squiggly joint lines, but it's not ready at this time.
Note: A solid squiggly lintel is always squiggly, regardless of scale.
The Joint Pen is used to draw the joint lines on a non-squiggly or low-scale arch. This pen should be 150, the usual surface hatch pen. In addition, squiggly arch stones are modeled using this pen, so they don't stand out so much.
Materials: The visible arch/lintel will use the Arch Material. For a Squiggly, Segmented arch, the visible, squiggly stones are actually thin plates applied to the front of the wall. (You can't tell.) Behind that, within the wall, is a regular lintel, built with none of its edges visible. This is so the arch appears consistently in section. This invisible piece takes the material of the edge of the wall. If you look at the shaded view and see a funny color within the arch, check the wall's edge material. (For stone walls, the edge material should be stone so the masonry reveals look right.)
Jambs of two arches
The overhead lines (Cased Op Lines) can be switched off individually.
Here are some 'recipes' for typical applications:
Precast lintel: Flat on, Solid, Squiggly off, lintel bearing>0.
Stone lintel: Flat on, Solid, Squiggly on, lintel bearing>0.
Flat Stone arch: Flat on, Segmented, Squiggly on.
Stone arch: Flat off, Segmented, Squiggly on.
Brick jack arch: Flat on, Segmented, Squiggly off, lintel angle>0.