Abstract: This invention concerns automatically generating embroidery stitch patterns in a computer aided design system where areas defined by vector outline shapes are filled with stitches which follow curved lines rather than straight lines. This is done in a way to maintain consistent densities and consistent needle penetration patterns inside the areas. The shapes of the areas may be simple polygons which can be filled in one contiguous segment of curved stitching, or they may be complex or multi-boundary shapes which must be stitched in more than one distinct segments of curved line stitching. The areas are transformed into another coordinate space where known calculation methods for straight line stitching are used to calculate straight line fills of the transformed area.