Arc by Points Preferences
Doubleclicking the Arc by Points tool in the toolbox (or pressing the Enter key when the tool is selected) will bring up its preferences dialog:
Rotate at Collisions Tool Location
1. Third Point Indicates Direction
Chooses the mode used to adjust the arc through its endpoints. When enabled, the third point is used to specify the tangent angle of the arc at its endpoint; otherwise, the arc must pass through the third point. Can be toggles on the fly by pressing the key assigned to “Increase Diameter” in the native Keyboard Shortcuts dialog (by default, for English-speaking locales, the right bracket key “]”). (See Arc by Points: Tool Operation)
2. Display Arc Radial Center
When enabled, the arc’s current radial center point will be annotated with a small cross while it is being created.
3. Annotation Color
Allows a choice of colors in which to annotate the arc’s radial center and/or the third point direction line, from among red, blue, magenta, green, black, and grey.
4. Display Radius Value
When enabled, the current radius of the arc is displayed next to the cursor.
5. Snap to Existing Path Points
When enabled, the cursor will snap to anchor points with a red snapping ring even when Smart Guides are turned off.
6. Snap When Path Continuation is Tangent
When enabled, and Third Point Indicates Direction is also enabled, and the arc was started at the end of an open path, then the cursor will snap to positions where the arc continues the open path in a tangent direction, or 180° opposed to it. A small “S” (or “T”, when the path reverses direction) will be displayed above the join point:
Arc by Points Tool - Snap to Tangents Option
7. Automatically Join to Existing Paths
When enabled, and the arc begins or ends at the endpoint of an existing open path, then the arc is joined to that path. Can be toggled on the fly (when dragging the third point) using the J key.
8. Replace Existing Path Segments
When enabled, and the arc starts at an anchor point of an existing path and ends at an adjacent anchor point, the arc replaces the existing path’s segment. Automatically Join to Existing Paths must also be enabled.
9. Retain Selection
When enabled, objects which are already selected when an arc is created will remain selected afterwards.
10. Slow-Drag Divider
Specifies the factor by which the cursor’s movement will be divided when using Slow-Drag (see Arc by Points: Tool Operation). The value can range from 1 to 500, with higher values allowing for smaller movements of the cursor.
11. Informational area
Shows a brief description of each preference control when the cursor is being hovered over it.