Before you give up, try these solutions from simplest to most advanced.
The Round Corner algorithm works by offsetting edges and trimming geometry. When you apply a fillet to a vertical edge that meets a flat top surface, the extension tries to blend the curve into the plane. If the radius of the corner is too large relative to the thickness of the top slab, the geometry collapses into itself, creating "cracks."
In short: The circle of the fillet is trying to eat into a space where there is no more geometry. sketchup round corner crack top
After running Round Corner, Zoom in on the crack.
Before running Round Corner:
Before fixing the problem, you must understand it. The Round Corner plugin works by offsetting, extruding, and stitching geometry. When you apply a fillet to a hard edge, SketchUp’s geometry engine (based on polygons, not true NURBS curves) must triangulate complex intersections.
The "crack top" specifically occurs when the rounding algorithm fails to properly cap or weld the vertices on the uppermost horizontal plane. Instead of a continuous surface, you get: Before you give up, try these solutions from
This is most common when:
If Fredo6 Round Corner consistently cracks your top geometry, switch to these alternatives: This is most common when: If Fredo6 Round
