sketchUcation

Install the extension via the Preferences->Install Extension button. It will add a "Circle Intersect" item to the Extensions menu and will also create a toolbar/palette named "Circle Intersect".

This extension calculates the true locations of intersections between a SketchUp circle or circular arc and another circle, circular arc, edge, or construction line. It uses the defining metadata (center, radius, plane) of the circle in the mathematical formulas for the intersections instead of SketchUp's polygon representation. It places a guide point at each of the intersections (when the entities are just tangent, there may be only one point).

When applied to partial arcs, the extension treats the arc as if it were a whole circle. That is, it will find intersections that may be beyond the ends of a partial arc. This treatment is important because if any other geometry crosses a circle, it will usually split the circle into several partial arcs.

When applied to a edge, the extension uses the mathematical line containing the edge, that is, it implicitly extends the edge infinitely in both directions to where it intersects the circle.

The extension is meant to be used for purposes such as triangulation without worrying about whether the intersections lie at vertices of the circle or arc representation in SketchUp.

Draw the geometry first, then activate the tool either from the Extensions menu or via its toolbar. Select the first circle or arc, then the other circle, arc, edge, or construction line to intersect. As soon as you click the second entity, the guide points will be added.

Special notes and restrictions: - the entities to be intersected must be coplanar. - the entities to be intersected must be in the same edit context (model, Group or Component) - with the exception of construction lines, the entities may be selected without opening their Group or Component for edit. You can't select construction lines without opening their edit context. - the guide points will be placed in the same context (model, Group, or Component) as the intersecting entities

April 6, 2016 Version 1.0 initial release