Sketchup Round Corner Crack

If RoundCorner continues to crack, abandon the plugin. SketchUp's native Follow Me tool is bulletproof.

How to Round Corners Natively:

Note: This requires the edges to be a continuous loop. It creates perfect geometry 100% of the time without crashing, though it takes 30 seconds longer than pressing the RoundCorner button.

Visually, the crack appears as a thin, white, jagged gap or a series of broken lines along the edge where a rounded corner meets the main body of your object. It looks like the rounded piece is separating from the rest of the geometry.

This happens almost exclusively when you use Round Corner (by Fredo6) or Solid Tools on complex meshes. sketchup round corner crack

You don't need to restart your model. Here are the three fastest ways to fix the round corner crack, ranked from "lazy" to "pro."

If you have tried all the above and the extension still fails, you are likely dealing with a degenerate face. Here is the nuclear option:

The primary selling point of RoundCorner is automation. In native SketchUp, rounding a corner on a simple box involves drawing arcs, tracing lines, and manually deleting waste—and that is just a cube. Imagine doing that on a complex piece of furniture.

RoundCorner handles this instantly. You simply select your edges, type in your radius, and hit enter. If RoundCorner continues to crack, abandon the plugin

The "Round Corner crack" isn't a bug in your model—it is a mathematical limitation of SketchUp's kernel. The most reliable fix is always scaling up (Step #2). If you remember nothing else, remember this: Make it big, round it, shrink it back.

Have a specific crack pattern not mentioned here? Export the geometry as an .obj and re-import it—this often resets the triangulation and solves the problem instantly.

When searching for a "proper" feature to round corners in SketchUp, users are usually looking for a tool that is robust, doesn't break the geometry (creating cracks or black faces), and is easy to use.

While the term "crack" might refer to a specific plugin name you heard, it is more likely you are looking for the industry-standard solution to avoid "cracks" (geometry failures) when rounding corners. Note: This requires the edges to be a continuous loop

Here is the breakdown of the proper features and plugins to achieve this:

In the SketchUp community, the "crack" refers to three distinct but related failures when using the RoundCorner extension (by Fredo6):

These issues usually occur when processing high-polygon curves or low-tolerance edges.

Before you throw your mouse, follow this diagnostic workflow. It works for SketchUp 2017 through 2024 (and beyond).