Spiral

Module(s): Site Plan

You can use the Spiral tool to create optimized transition arcs. This tool is used for lines and circles that must not intersect and that do not touch.

To create transition arcs

1. Click Spiral (How).
   

   Activate Spiral in one of the following ways

   • Menu bar: Create Terrain Site Plan

   • Palette: Tools Create area in the following module(s):

   Site plan

   • Configuration: Landscaping/Urban Planning Site Plan flyout
2. Click the first element to be joined.
3. Click the second element to be joined.
   The transition arc is drawn in. Any connecting elements are shortened or lengthened accordingly.
4. Press ESC to quit the tool.

Examples of transition arcs

Notes:

• You can specify whether transition arcs connect linearly or quadratically in the Options.
• For a pair of clothoids forming an S-shape, the program uses the same parameter A.
• If you want to create clothoids with modifiable parameters, use the Modify Element Parameters tool.