I have been getting bugs when I try to intersect faces quite frequently lately. When I intersect a simple cube into a face, the face gets triangulated:
The triangulation can be easily erased, but it is starting to get annoying doing this so often now.
Interestingly, if I scale down all the geometry down by a factor of 10, the triangulation does not happen. I think perhaps there is a mismatch between the precision with which SketchUp deals with one kind of operation (creation of planar faces) and another (intersection of face).
If you observe the image above (and the model attached), you’ll notice that the vertices of the face on the Z-axis varies by a maximum of 0.000414mm - this amounts to 0.000016 inches. As I understand it, SketchUp treats points spaced less than 0.001 inches apart to be the same point for tolerance purposes. But it seems that when dealing with faces/planes (or maybe just the intersection tool), the tolerance is much smaller (by a factor of about 100, I think).
Therefore, I think there is a bug to be resolved here.
On a further note…
I have been getting what I think are tolerance issues quite a lot when dealing faces lately. I have been getting lots of duplicate faces, for instance when bisecting a face with a line. It happens most often with highly developed models, not at the beginning stages of building.
I suspect that rectilinear, axis-aligned geometry start to go ever so out of line (but still within Sketchup’s tolerance), after multiple changes to the axes of a component, which performs transformations to the geometry. For complex models, changing the axes while modelling is something that is very useful, and not something I am prepared to give up just yet.
The model attached is a piece of a larger model I have been working on for some time. You can try to intersect the face with the group, and see the triangulation happen:
Component_11.skp (56.9 KB)