About Round Patches and Round Pieces

To successfully exclude, trim, or extend round geometry, an understanding and accurate identification of round patches and pieces is necessary. A round piece is simply round geometry that is placed at the selected references. A round piece can contain patches. A patch is a neighbor that is tangent to the end of the round piece that is being created. This tangency occurs due to existing model geometry. The following table illustrates round patches and pieces:

One Round Piece with Three Patches	Two Round Pieces without Patches
After you select the edge reference, the system automatically propagates the round piece across all tangent points resulting in tangent segments called patches. In the illustration below, tangency occurs due to the existing round geometry.	After you select two edge references, they system places two separate round pieces at the selected references to create the round. In the illustration below, tangency does not occur due to the vertex. This results in the two overlapping round pieces. The system uses transitions to resolve this discontinuous geometry.
1. Edge reference 2. Patch 3. Patch 4. Patch 5. Existing round geometry	1. Edge references 2. Discontinuous round geometry