SketchUp has a well-known internal limitation where it struggles to create faces with edges shorter than approximately 1/16 of an inch (or 1mm). If your rounding radius is small, or the segments are highly detailed, the plugin tries to generate tiny faces. SketchUp fails to close these loops, leaving visible "cracks" or holes.
Often, the crack isn't a hole; it's a hidden edge or a reversed face. Zoom into the crack top.
SketchUp has difficulty forming very small faces (under 1mm or 1/16 inch). When you round a corner with a high segment count, the resulting faces may be too small for SketchUp to "heal," leaving a gap or crack. sketchup round corner crack top
To fix a problem, you first need to understand its root cause. The "crack top" issue isn't random; it stems from the fundamental way SketchUp's geometry engine works.
SketchUp cannot easily create faces or edges shorter than 0.001 inches (about 0.025 mm). If your model is small, or your rounding radius is tiny, the extension tries to generate geometry below this threshold. SketchUp ignores these tiny segments, leaving a literal hole or "crack" where the new face should be. 2. Non-Manifold or Dirty Geometry SketchUp has a well-known internal limitation where it
If your model is already showing cracks or messy geometry on the top surface, here are the most effective solutions: 1. Reduce the Offset (Radius) Value
If you have already applied the operation and notice small cracks or missing triangles on the top surface, you can heal the geometry manually. Often, the crack isn't a hole; it's a
This gives you total control and eliminates the crack because the top face never touched the rounding algorithm.
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.
: Select the copy, press S , and scale it up by 100x or 1000x .