Converting Circles, Donuts, and Ellipses to Polygons

Circles, donuts, and ellipses are stored in the database as true conics with centerpoints and radii. You might need to convert conics to polygons before streaming out your database for chip production.

The Convert To Polygon command fully supports ROD objects, except for rectangles and multipart rectangles. The command has no effect on rectangles and multipart rectangles.

When you convert a multipart path, the polygon resulting from the master path is a ROD object and takes the name of the multipart path. Subparts, if any, become unnamed, ordinary database shapes (paths and rectangles). Subparts are not converted to polygons.

When you convert any ROD object (except rectangles and multipart rectangles) to a polygon, all alignments to the converted object are deleted.

The Convert to Polygon command does not support blockage and boundary objects. In pre-selection mode, the command fails, and an error message is displayed appear in the CIW. In post-selection mode, the command fails to select the blockage and boundary objects.

To convert a conic to a polygon:

1. In the layout window, choose Edit – Convert – To Polygon.
2. Click the conic that you want to convert.
   The conic is redrawn as a polygon, using many straight-line segments to create each curve.
3. Continue clicking on each conic that you want to convert.
4. Press Esc to stop converting shapes to polygons.
   No conversion happens if you run the Convert to Polygon command on a rectangle or a polygon. A message appears in the CIW if you attempt to convert a rectangle or polygon to a polygon.

Setting Conic Sides

You can set the number of segments used when recreating conics when you convert them to polygons. The minimum number of conic sides is 3, and the maximum number of conic sides is 4000. The default number of segments is 20.

To set the number of conic sides:

1. Choose Options – Editor.
   The Layout Editor Options form opens.
2. Type a value in the Conic Sides field.
3. Click OK.

Related Topics

Layout Editor Options Form

Object Conversion

Instance-to-Mosaic Conversion

Converting Instances to Mosaics

Converting Polygons to Paths

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