Subdivision sketch: truncated cones.

These examples show how segment matching can be used to join truncated cones to curved surfaces.

When the support loop around an intersecting shape disrupts the segment spacing of an existing shape, it tends to cause unintended deformation that can generate visible smoothing artifacts. Simplifying the support loop routing, by using the geometry of the existing shape to support the shape intersection, maintains consistent segment spacing and helps reduce the visibility of smoothing artifacts caused by abrupt changes in the topology.

Truncated cone joined to cylinder: This will generally behave like a simple cylinder to cylinder intersection. Align the segments in both shapes and simplify the support loops around the shape intersection whenever possible.

Truncated cone with adjacent cylinder joined to cylinder: Adjust the number of segments in each shape to maintain a relatively consistent geometry density while also aligning the edges around the shape intersection.

Truncated cone with radially clocked cylinder joined to cylinder: Start by aligning the segments in the shapes then add perpendicular support loops, as required, to match the support loops around the base of the shape intersection.

Truncated cone with adjacent cylinder joined to truncated cone: Get the alignment as close as possible then constrain any differences in the shapes to the area between the inner and outer support loops around the shape intersections.

Truncated cone joined to chamfered cylinder: Rotate the intersecting geometry as required and adjust the number of segments in each shape to align the edges around the base of the intersection. Perfect alignment isn't always possible but close enough is usually good enough. Perpendicular edge loops can be routed across the intersecting shape or reduced with a triangular quad.

Angled cylinder joined to truncated cone: Steeper tapers and proportionally larger intersecting shapes tend to amplify the difference between the segment spacing around the extreme ends of the shape intersection. Using the minimum amount of geometry required for each shape can help reduce the overall complexity and make it a lot easier to join the two shapes, without generating unintended shape deformations.

Recap: Adjust the number of segments to align the edges around intersections while also preserving the accuracy of the underlying shapes. Simplify topology routing and use the existing geometry to maintain the segment spacing of curved surfaces. Rotate intersecting geometry to align the edges without adding unnecessary mesh complexity.