FormIt is a polyhedral modeling system, so objects like circles, arcs, and splines are represented by a series of straight edges. Similarly, a curved surface like the wall of a cylinder, or a dome, is comprised of a series of planar faces with hidden border edges.
By default, FormIt uses 40 edges, or facets, to represent a circle, and 24 facets to represent a 3D, curved object like a cylinder. For more complex surfaces like a dome, a value of 24 sets the perimeter faceting count, and also impacts how densely faceted the rest of the shape is.
In FormIt for Windows v18 and newer, the curve and surface faceting values are customizable:
Curve Faceting Quality
Changing the Curve Faceting Quality will affect how many facets are used when drawing new circles and arcs in FormIt, as well as when placing primitive shapes. For example, setting this to 64 would create a 64-sided full circle, or a quarter-circle arc with 16 facets.
This value will also affect the quality of circles and arcs imported from SAT files, as well as when baking geometry from Dynamo. You can set this value for all new sketches, or just the current sketch.
For existing curves, you can also use the Rebuild Curve plugin to retroactively rebuild an existing arc or circle with a new faceting count:
Surface Faceting Quality
Changing this global setting will affect the quality of 3D curved surfaces imported from SAT files and when baked from Dynamo.
For example, setting this to 64 then baking a sphere from Dynamo will use 64 faces around the equator of the sphere, plus 64 facets in each of the rings going to the poles of the sphere, which adds up quickly! Use higher values with caution, as it can affect the performance of FormIt in some cases. Once you've got a result that's high quality, you can convert it into a Mesh to improve performance.
When working with Dynamo, you can modify the faceting quality, and hit "Run Graph" in the Properties Panel without changing any parameters, to take advantage of new faceting counts:
As with curves, you can set the surface faceting quality for all new sketches, or for the current sketch only.
Note that faceting values are currently limited to multiples of 4, so when entering numbers manually, FormIt will round to the nearest multiple. You can use the sliders and arrows to cycle through accepted values.