@youngosg said: t = Geom::Transformation.scaling 2 There is an issue with this method - it doesn't produce the same transformation as Geom::Transformation.scaling(2, 2, 2) The former change the 16th value in the matrix - instead of scaling the components. I'm not sure why it was implemented as such, but several render engines have had issues with that. I think even SU have issues in some cases. Think we have an issue filed to change it.

I've also had this happen frequently. It may be due to the dividing line not being completely closed. Try drawing lines from the dividing edge to the outer edge, to hone in on where the gap is. If the above suggestion from myself or others do not work, I've also found that it's sometimes due to distance of the model from the origin or if the model is too small, messing with Sketchup's calculations. Try moving it back to the origin (changing axis location does not move the origin) or scaling the model up by 1000 (and back down after you're done working on it, if needed).

Try the groups' .bounds if they 'touch', then some_group.bounds.max.x OR .y OR .z and some_other_group.bounds.min.x OR .y OR .z might be coincident ?? Especially if the are simple boxes...

@dan rathbun said: My point remains valid. You CAN see the code. You can see what exceptions the API methods raise internally themselves and their messages for ArgumentError and TypeError exceptions. It is in fact not easy to see where all the errors are raised from. I was struggling with that the other day while I was working on an issue. There are a lot of utility methods that might raise errors and it's not easy to see all the code paths. I didn't intent to make an excuse to not so anything, but the majority of the API was made many years ago - long before anyone on my team was around. Tracing down all of them would be a lot of work. Would have been easier had it been done since the design, but alas. Just wanted to give some insight to why things are such as they are. It doesn't mean we don't agree with you. That the documentation is not the best is well known, and you know I've ranted for years about it. One thing we really do want is a new documentation site - a new developer site.

or, to make a discrete selection and use the move tool

@fluffy82 said: I would just draw a guideline through both points, no need for complicated scripts or plugins ^^ The OP did ask for a Plugin that did this... But yes, there are many ways to judge this 'visually'...

If the inner part is truly separate you can triple click it and delete. As you say it is a solid,I assume that it is separate.

Why didn't you ask your real question in the first place?

Three videos on how to close a hole! Awesome!